Instead of eliminating vegetables, the intake of fruits and veggies should be increased to take up a large portion of the diet, if not constitute the whole diet, if you are looking to improve your digestion. In the mucosa, T cells are found in two locations: Reliability, validity and accuracy - what do they mean? How do I stop my stomach from making weird noises? Yes, but only organic soy milk.
My diet usually consists of: I am pretty pissed off right now because I feel like I am running out of things to eat! But then again… reading some of these comments made me sad, realizing there are people out there that have even less to choose from than I do. I guess the harsh reality is that we probably all need to start living in a bubble and drinking distilled water….
Hi Mel, this might be helpful, I remember reading this article in my local paper about years ago. I was eating about servings of vegetables each day, 3 of which were raw. After about a year and a half I developed pains in my upper abdomen. I read this article and it turns out the vegetables were likely causing it. I cut way back and am slowly adding a small amount back daily. The pain left almost immediately. It was almost like a constant gas pain that got better or worse sporadically, but was always there.
Thank you so much for this article! It helped me so much. I was doing the exact same thing. Having way too many vegetables and a raw salad everyday. I juice my vegetables, and after I make sauerkraut, put it in a french press and just drink the brine. I cant take probiotic pills because of the resitstant starch.. I mess up once and its back to square one…I only eat grass fed beef, juiced vegetables with nutritional yeast and himalayn salt and turmeric, and like 5 avocados a day.
I do drink coffee, but not so much. Kim, I of course have stomach issues too but I can eat small romaine salads and small potions or cooked veg. I eat fish very often , tuna, salmon, shrimp, cod etc. I eat EVOO and avocados and small portions of nuts. NO carbs other than green veggies. Do you eat fish? Red meat can be hard to digest.
Grains and starch will mess me up faster than anything. I am reading everything everyone is eating…brines, veggy presses, seafood, bits of salad and nuts…no carbs or dairy.
All I can eat and be able to leave the house to work all day nornally, is rice krispies, rice chex, rice crackers, rice cakes…and dairy to go with the cereal, and cottage cheese or thin cheese slices to go with the crackers cakes. I could have beef or chicken if I could afford it, but I am unemployed. When I did work, I subbed by day, taught night school, and worked at a greenhouse seasonally. What kept me alive was night school and now that it is gone…no money for anything.
I wish there was a doctor that cared to find out, but I have never found one. Cheese and dairy are expensive. Buy chicken or ground turkey instead. I could never eat rice and dairy or I would be in pain all day.
They are the worst. Find some undairy, ungrains you can have. Most of us have very restrictive diets. You are not alone. I am not trying to be dense here, but I really have no idea.
Rice is the only thing my body likes. As there are soy milks and almond milks. I know what to stay away from so that I am not in serious agony, but I still have trouble making it from , as an example, without having to be in the bathroom a lot, daily.
So, I have no idea what non-grain, non-dairy thing, except plain meat, there is out there. I assume I would still get sick if all I ate was meat. Take a look at this blog. I should have said NO grains or dairy. I would go for almond milk before any other kind including soy. If your body liked rice and dairy you would not be in the bathroom all the time.
I eat meals of proteins about 3 oz on a small salad with olive oil and a few shredded veggies. I eat small amounts of nuts and other veggies. Simple, nutritious and keeps the stomach happy. I also keep meal sizes small. As for what you can afford I have no advice. Have you ever tried fasting to give your system a cleanse?
Occasionally I eat BF and nothing until dinner. There is not one single veggy or fruit I can have in any quantity if I want to leave the house. But never eating again, will be hard.
Fine if I am staying home, really bad if I am working 16 hours a day, which I used to do when doing day and night school. I can get a free colonoscopy, but I would have to pay out of pocket for the biopsy, even on Obummercare.
I am currently unemployed with three worthless college degrees they used to be worth something, but not anymore , and paying the premium is more than I can afford…but I do it anyway, and then never see a doctor ever…no matter what. I read your posts. Sounds a lot like what my son goes through. He was diagnosed with Chrons. Finally after 10 hours in the ER they did admit him, once admitted the doctor saw him he ordered a colonoscopy. They biopsied and diagnosed Chrons.
My son filled out the paperwork and that was the end of it. Please check into this route. If you are eating at less as you are and having as many stools as you are having you are probably becoming very malnourished.
I was born at 24 weeks, and I have never been able to eat things easily, but as I get older I lose more and more items. I recently lost my job and I will have to get two or three part-time jobs, if I can find them with my college degrees, as I have not been able to get back into my field. I am living on Rice Krispies, Rice Chex, rice crackers, plain cooked rice, old-fashioned cooked oatmeal. I do not have trouble with white gluten and have never tested positive for a gluten problem, and I can have dairy…so other than rice things and oatmeal, I have Italian bread and cheese.
I can still have days where I am totally unable to go to work. I also have steroid shots, when I can afford them for my skin…and my behind can become very raw after a day of wiping. I had a barium enema in and I was told I was fine. I pooed from Sunday to Saturday with cleaning out and then trying to get the barium out and it took weeks of only having liquids to get my butt skin to heal…I never wanted to poo again.
I was a high school math teacher and it was hard to stay in my room from 7: They closed my school during the first week of school without warning…and there are no teaching jobs in September and I am overqualified for everything with three college degrees…so there is little hope at finding a job that will allow me to go to the bathroom when I need to do.
I just called them and that is what they said. Thus, trying to get further medical help is all but futile at this point. I have been where you are as far as the insurance thing goes and not having much money for food…. I would highly recommend you go check out the website healthygutgirl.
I have come a long way with healing muself with everything I have learned from healthy gut girl. Make bone broth super cheap and sip all day, fermented veggies and coconut water kefir.
Take HCL and digestive enzymes. Stay away from dairy. Jennifer you seem to be going through a lot. I struggle with the same. No matter what you eat you will be in agony. Do you have close friends? Or a support system? You need to start talking to people and getting things off your chest more often. Or call befrienders or samaritans. I believe that if you start to resolve the emotional issues it will help a lot and then you can truly focus on the diet and what to eat. Hello Jennifer, I was born premature and I experienced a realization that I have probably suffered from hyper-sensitivity issues all my life.
Thank you for understanding, not many people do. Thus, I have to eat very, very little. Say one bowl of old-fashioned cooked oatmeal each evening. That means having no life…just existing to pay bills. Lots of people do it, but not forever.
I have spent the last eight years working three jobs, that just happened to work around each other. But there is nothing interesting to eat or fun to do. I just spent several hours applying for a job and now I will do laundry.
The point is that I should have been given a disclaimer from the doctors that saved me. Something along the lines that I would never be normal and I should at the very least be allowed to use the bathroom whenever I need to do and not jeopardize my job.
As a math teacher, that is not possible. I subbed by day, taught night school so 16 hour days , and worked at a greenhouse seasonally often alone. However, I knew the days off, had a few understanding teachers that would watch both rooms…hard to do, but we did it…when I had an extreme emergency.
Otherwise I would simply hold it and hit the bathroom before school, during planning, lunch, after school, during evening dinner break, and be very sore by the end of the day. But that is only seasonal. This time of year I always had weekends off. Now I am looking at subbing by day, and working evenings and weekends at a grocery store…if they hire me.
I have no money for food, so it should be less of a problem. So, it would have been nice if the doctors that made sure I lived, also cared about the quality of life. Or that my current doctor could write the same thing. A cashier would be bad as you have to stay at your register, as an example. I found your post by accident. The most obvious thing here to me is the dairy.
If you do nothing else, get rid of dairy and see if that takes care of the issue. Live on brown rice if you have to for awhile. Jennifer, I have a lot of trouble with my body, with the digestion, absorption probably malabsorption, leaky gut, Candida fermented foods!
The bottom line is learning to trust my body and my inner guidance and that means Divine, too, for instance, dialoguing question and answer guidance. Part of my healing from extreme, complex abuse from birth until 28 years of age is writing out stream of consciousness from my inner world and drawing the pictures from different parts of my broken self. Doing that has lessened over the years but want to pay attention to that more as it helps me see more clearly what is going on in the un-subconscious which is even more important to me than the other, what is called the conscious part of the self.
All that I went through, which was tons of stuff, all held within the cells of my membranes and organs…. Talk on just the physical level does not do it for me. The emotional and feelings seem to be walked around, never mentioned or shunned. Everything is linked for me, physical, emotional, spiritual. It would mean finding the right people to give you supportive commentary and letters, etc. Having all those jobs in your condition seems like too much to expect for you and impossible?
Or is there another way to take this burden off your shoulders while you find out how to heal. I no longer sub by day and teach at night, with the greenhouse seasonally. I had 15 months without anything but subbing and the greenhouse, and I was living on savings. I ate mostly Cream of Rice hot cereal…it was tolerated well, but sooooo boring. I now work fulltime as a math teacher, and work the greenhouse seasonally.
Then I am planning all weekend. I have to be careful what I eat, so I am not living in the bathroom during the week…I could get fired, and I need this job. Thus I may never be able to afford meat. Life is stressful which makes bowel problems worse and food-wise very boring.
I will live dangerously and make a pot of soup over Thanksgiving and Christmas breaks…cheap, easy, and yummy, even if there is no meat…it will still taste incredible.
Hi, I was just reading this because I have digestive issues and thought that maybe I could give you something to help. You can juice one cabbage and drink it 4 times a day and then you eat whatever diet you can at the time and after a few weeks or months however soon you want to try start adding in more foods and seeing if your body can handle them again.
Best of luck to you! I have never had good results with cabbage. I found a really nice soy free stock, so I could try to make my own soup, as all canned varieties contain soy. However, it was spring break and I was not working, so I thought I would brave trying it to see if it was better than canned soup.
I have been to my new Obummercare doctor office three times in three years for the free yearly checkup, and saw three different people…and all they do is look at me like I am from outer space when I tell them my digestive issues.
Thus, I have to make my innards as happy as possible…and that means Cream of Rice hot cereal…horribly boring meal after meal, day after day. I was trying to eat like I did decades ago. Gas, seizing, cramping, pain, bathroom problems, and I could not figure it out.
Maybe a smaller salad would do, maybe something with it could help, like it says here on this site, what a thought! But I like health, keep a good weight, eat right, but now, things have changed. I am not thirty or forty now, or fifty. So I find less is more now. I have fixed the problem, and then I went on this site, and found yes, less of certain vegetables, and some of another kind are good, and do not cause me the problems..
I take a probiotic after meals, that helps. Fermented food does not agree with my gut except Keefer so far. Will read more now. Over the months, and while also taking Xifaxan, Motil Pro, and enzymes, I have seen gradual improvement, but still suffer debilitating symptoms.
I find this very interesting as I have been a vegetarian for several years.. With that has come some problems.. Bloating, chronic constipation and Ill health.. Having stumbled on a book called Fibre Menace and reading your article I have been enlightened. Could you perhaps give me some suggestions on your daily diet.. I a a little confused with regards to soluble and insoluble fibers… A new door has been opened to me and I am determined to get well Many thanks Nicky. I seem to have a great deal of trouble with the insoluble veggies.
I think I am going to return to the potatoes and sauerkraut that I was raised with. I also recently had a colonoscopy. I can eat starchy veggies, and cooked veggies, but even if I boil and puree one zucchini or some bok choy, I get instant cramps.
I am way skinny, so cannot afford diarrhea. It seems that my probiotic, Culturelle, is also giving me diarrhea, so had to stop it. Recently I added Butterhead lettuce to my smoothie and it constipated me then I could not stop going to the bathroom. A really useful article! However, the indigestion problem got worse. And now I see your post, I think I should try to eat less, quantity and kind, vegetable and more meat. Can you take presript assist probiotics if you have SIBO???
I learned this lesson the hard way…I used to consume huge servings of high fiber vegetables and man did they do a job on my gut. Now, I limit the variety low fodmap and the serving size and life is much better.
Love your article Chris! But it gets worst with animal intake fullness and nausea and with cherries severe bloating. Do not eat fiber unless is steamed and easy to digest like carrots, zucchini or pumpkin. Eat proteins and healthy fats along with betaine hcl or digestive enzymes, it help a lot. I constantly feel a lump in my throat, maybe mucus.
Silvie, This is me exactly!!!! Pylori 15 months ago, and have the same issues as you!! I also have celiac disease. I am trying to eliminate corn and dairy. Also processed food and sugar. There are days when I only have one small meal or just some bread. I do like some meat, small potions, no more pasta or processed food. I have a general question for whomever might have even a suggestion. Blood work and overall energy has shown low-T and was put on armor thyroid. I try and get tons of sleep, drink lots of water, exercise regularly, epsome salt soaks, hot lemon water, decaf coffee, lots of vitamin c and magnesium.
Diet, lifestyle, or other suggestions would be much appreciated! Thanks for your time. This might seam odd, but had same problems, What I learned through my journey is to listen to your body, simple as. Used to be vegetarian- loads of raw veggies and fruits, always bloated and constipated.
I have a daughter just diagnosed with IBS-C. She has been a vegan for awhile. She changed her diet to mostly raw in December to combat the IBS. It worked briefly and then it stopped working. She is back on laxatives. She has had an endoscopy which revealed lactose intolerance. I partly blame the raw foodists who she follows that tout the life saving benefits of their lifestyle.
It may be for some, but not for all. My daughter will not eat meat ever as an ethical matter. She needs to try the lowFodmap diet to see if it will help. We are in a tough situation. That is a tough situation. I was in a similar one. For example, certain kinds of tofu firm, I think , small amounts of lentils and possibly whey protein are acceptable. I have been suffering with ibs since 2 years ago. There are certain food that some website list can be eaten by ibs person that cause me stomach cramp and diarrhea.
Like potato,sweet potato and yam and even tomato. Now, i am afraid to eat any vegetables or fruits. Banana and apple are very harmful for me. May I suggest to your daughter that eating a whole foods diet will put less pressure on her. I am celiac, lactose intolerant, have difficulties digesting raw vegetables and have a great many food sensitivities.
I cook roast grill steam all my veggies, and mostly with a healthy oil added, and cooked at lower temps. Including a healthy fat in most of my meals helps with feeling satiated as well as adding being healthful. Avacodos olives coconut oil to name a few. Tonight my dinner was steamed corn and peas, artichokes in vinegar, an avacodo and wild pink salmon canned. Live by what feels good and being open to following different ways of eating.
I eat one large meal towards the end of the day. Start my day with fresh lemons in water warm and room temp, never cold and fruit only until mid day with nuts and dried fruit until my meal. I found a big difference when I ate fruit alone and first part of day. I am 49 and really in the best health ever. Listen to your body. Stay away from processed and read labels. Less then five ingredients and they have to be real.
Never things that say or include the word natural. I can also eat some goat cheese and some tofu but am having problems digesting all things soy, all legumes. Eating canned salmon agrees with me but not cooked. I also eat a lot of potatoes and root veggies. I also try to include organic and definitely non gmo. Sorry for lengthy response but just wanted to say and show you have to listen to your body.
Keep reading and learning. For those that ask, I am a whole food eater with celiac and lactose intolerant. I bring food to share wherever I go. Last night I brought roasted root veggies and halva. My platters were first to go. Carry snacks with you at all times. Just came back from 2 months in India and made it work food wise. It has helped me in all aspects of my life.
Thank you for writing such informative information concerning how those, like myself, have digestive issues with insoluble vegetables. By reading this article it made me realize why my digestive system reacts to insoluble vegetables the way it does. Right now I am on a low residue diet and only eating soluble vegetables, mostly carrots and beets and finding my stomach so much happier. If only the doctor that cares for you would share what one should and should not eat when the digestive system is so delicate, not just during an occurrence of diverticulitis but afterwards as well.
Keep your articles coming and thanks for all you do! Oh my God thank you for your article!!! But yep, tons of insoluble fiber on an empty belly, and always a variety. I highly recommend Kefir to anyone experiencing digestive probs. Thank you for your article. I have been having issues with my stomach swelling for about 8 months now and I have not been able to pinpoint what it is.
Lately I have been eating healthy I am not overweight, just getting closer to 40 and I am trying to be healthier. Every time I eat a salad I love salads my belly swells and I am gassy for days after.
I believe it has to be the vegetables. When I eat cooked vegetables it is not so bad. This really is no good because it takes away a lot of my quick healthy snacks and I love my snacks. Oh well, I guess. How about drinking a lot of water? I had a salad almost three years ago and that is the last time I have had anything except for potatoes since. That experience led to a lot of pain, severe dehydration, throwing up, and diarrhea.
Though it may help some, not all people that will help. I started juicing a couple weeks ago and eating fresh veggies often. It looks like that might actually be my problem! Thanks for the article. Only way I can eat most veggies and some fruit is by boiling them until they are limp and than puree ing them and making it like baby food.
Most the people that have posted seem to be under weight and here I am about 80 pounds to lose. Tho I eat very little as I have so many intolerances and bouts of bloating and diarrhea.
Have a very hard time losing anything. Have a hard time eating anything. Something has to give. I also cannot eat most vegetables and most fruits. I am also lactose intolerant as well. No juice and no red wine. I need to lose about 80 lbs as well. I love tomatoes but when I have them even making a sauce I am in the bathroom for two days.
Thanks for the article on soluble foods and insoluble foods. I have very bad IBS, and I think raw vegetables really create havoc in my stomach. One thing for sure is that I have to lose weight.
On wiki it says broccoli is a soluble fiber but here it says insoluble. I had HUGE histamine and food intolerances. Again, in 8 weeks of insulin I can eat as much canned fish as I want and drink red wine and gained all my lost weight back. Point is, have you had your blood sugar tested? Hi, google high carb diet cures diabetes. Also google diabetes — disease of fat cells. I think it will turn your health and world around. Type one diabetes does not result from poor eating habits as Type two often does.
I really wish Chris Kresser would address the problem of histamine intolerance and fermented foods. For the last 8 months I have developed food sensitivies all over the place. I am down to meat and vegetables to control the dizziness from the histamine. I have been eating egg yolk, liver, beef, chicken.
I am lined up with a Naturapath to get to the root cause, but it seems like forever for the appointment to get here. Sadly, I put a tsp of sauerkraut juice in my steamed greens today and felt the histamine right away. I went to a GI to get some tests.
I have pain on my left side high under the ribs. My allergist said, Candida overgrowth and the GI said, no, just take antihistamines and antacids and eat wheat every day. If I eat rice or oats and potatoes, then I feed Candida if I have it! What are the answers? Thinks It might be candida like you mentioned in lungs or track. I have a clean colonoscopy… I have to do three of the following… Oregano oil under my thong will help with candida issues. Kale interferes with thyroid function and make you feel quite sick and tired.
INQUIRE So far, The oregano oil is helping with candida issues… I started 4 drops under my tong once a day the burning is less acute… I will cook veggies for two weeks to see if it helps… I am a very healthy person… I should not be sick.
For the fungi candida… You could take probiotic formula for the gut flora.. Please see your specialist or general practitioner. Seeking medical advice from a blog is really really wrong.
Three different professionals could give you entirely contradictory advice. Each will charge you money for it.
I saw at least 10 different specialists and M. None of them had a clue what was going on. All they did was presribe more and more pills to treat the symptoms, not the cause which never worked. The doctors never even tried to find a cause and they certainly never looked at nutrition. Most of the people reading this blog HAVE seen many doctors, to no avail, and are now desperate.
You should have a hair mineral analysis done through one of Dr. They do Nutritional Balancing Science and test the hair for necessary minerals and heavy metals. Little did I know that these things in the body are the cause for just about all ill health.
Once they get your personal test results, they tell you what supplements to take to change your body from within so it can heal from the inside out. It changed my health and my life. His website has hundreds of articles explaining almost every condition you could think of.
I found the Blood Type Diet very helpful in determining the right diet for me. Every person I know who has tried it says it has worked for them. For most people the complete elimination of gluten grains or grains in general as well as dairy alleviate a lot of their troubles.
Then it was all down hill from there! Grease is NOT my friend. Before I had my gallbladder removed I had been doing the Suzanne Sommers Diet and lost a temendous amout of weigh only to gain and then some back. Now, my diet is meat, and bread; crackers, rice boiled veggies small amount.
I get so bored with my diet, I just crave fruits and veggies! I forget about that awful gut wrenching pain I get when I eat fruits and veggies. I call it food amnesia. Just the other day, I had bought some carrots for my daughter to nosh on afterschool.
I also had a juicer that I bought years ago and had never taken out of the box. Receptor activation results in expression of genes, the products of which contribute to defending the organism against infection. Purpose of the molecule: Coordination of a non-adaptive defense reaction on a local and a systemic level. We will first consider abstract strategy, then practical mechanisms. In case an epithelial barrier is breached, it is essential to confine the ensuing bacterial infection to this area.
The most dangerous development possible would be the distribution of these pathogens via the blood over the entire organism, a life-threatening complication termed sepsis.
This can be prevented by enhancing permeability of the small blood vessels and closing the draining venules by clotting. The lymph node with its many phagocytes acts as a filter, preventing further spreading.
At the same time, leukocytes are recruited from the blood to the primary infection area and endothelial cells are instructed to help them pass. Occasionally, they come too late, and the bacteria have already spread. Everywhere in the body, macrophages are activated by the distributed bacteria. Everywhere in the body, the coagulation cascade is kicked off, together with the fibrinolytic cascade, consuming all available clotting factors disseminated intravascular coagulation and causing profuse bleeding.
Once these processes are under way, they are extremely difficult to stop. Most patients in this condition are lost. This causes fever, the sensation of feeling sick with conservation of energy, but mobilization of energy to produce more defense equipment: All these effects increase the chances of successfully fighting back the infection.
The induction of proteases in inflammatory cells may lead to considerable tissue destruction, as seen in rheumatoid arthrits and in fistulating Crohn's disease. Viruses seem to be less readily detected by non-adaptive mechanisms than bacteria, fungi or parasites. This is probably due to the fact that they are produced in human cells, making their appearance "less unfamiliar" than that of other pathogens. We are therefore equipped with special innate systems to deal with viruses: Interferons IFNs were named for their ability to interfere with virus replication.
Three types of interferons were originally described, depending on the cell type used for purification: They have therefore been subsumed under the heading "type I-interferons". Type-I-interferons are signaling molecules secreted by virus-infected cells with the aim of slowing or inhibiting virus replication in neighboring cells. Again, this buys time to mount a more efficient, adaptive immune response. Most viruses, when replicating in human cells, give rise to intermediates consisting of long double-stranded RNA.
This type of RNA normally does not exist in human cells, which only contain RNA-molecules with very short double-stranded parts between loops. Consequently, the appearance of long stretches of double-stranded RNA is a pathogen-associated molecular pattern for potential viral infection, stimulating expression and secretion of type I-interferons. In contrast to some other PRRs, these are expressed by virtually all cell types.
One of the induced proteins is P1-kinase. By phosphorylating eukaryotic translation initiation factor eIF2, it inhibits ribosomal mRNA translation. This severely restricts replication opportunities for any virus infecting these cells, as it relies on the host cell machinery to produce virus proteins. Of course, this harsh measure negatively affects host cell functioning as well. A second anti-viral mechanism is activated by induction of the oligoadenylate synthase enzyme.
This enzyme oligomerizes ATP by catalyzing unusual 2'-5' bonds normally, nucleotide connections are 3'-5'. Additional proteins induced by type I-interferons facilitate the initiation of an adaptive immune response to eventually eliminate the virus. These include MHC class I molecules see section 2. R ecombinant type I interferons are injected as therapeutics. Viral infections would seem like logical indications, but interferons are both expensive and have considerable adverse effects, e.
Their application is therefore limited to life-threatening viral diseases, e. Additional applications are unrelated to viral infections, but are a logical consequence of interferons' effects.
Natural killer NK cells are similar in appearance and function to cytotoxic T lymphocytes, but lack the receptor T cells are using to identify virus-infected cells the T cell receptor: So how do they recognize cells that should be killed? One of the cellular properties activating NK cells may be characterized by the catch phrase missing or altered self. NK cells are important in the early phases of defense against certain viruses, but also against other infectious agents, as well as for the elimination of rogue cells to prevent tumor formation.
They express two types of receptors: The inhibiting receptors KIR- once acronym for killer inhibiting receptors , now more neutrally killer cell immunoglobulin-like receptors sense the presence of normal MHC-I molecules on cells probed by the NK cell. A cell with normal MHC-I will be left alone. Many viruses, especially herpes viruses, inhibit MHC-I expression in infected cells. Viruses using this trick have a selective advantage later on, as these cells cannot be identified as infected by cytotoxic T cells explained in sections 2.
Yet, with this strategy they make themselves vulnerable to attack by NK cells. In addition, NK cells may be activated by alternative mechanisms.
In some cells, this happens as the result of oncogenic transformation. The importance of this mechanism has been shown in the early defense against the protozoon Leishmania , which is spread by sand flies. Although NK cells are part of the non-adaptive immune system, they can also be directed to target structures by antibodies, in a mechanism termed antibody-dependent cellular cytotoxicity ADCC.
One big problem in defending against pathogens is that they reside in different compartments: To be able to fight pathogens in all these various circumstances, a broad spectrum of tools had to be developed.
Especially useful tools to combat extracellular pathogens are antibodies. IgM always consists of five joined immunoglobulin units, IgA sometimes of two. A few technical terms used in immunology: Functionally, an antibody has a variable and a constant region. While the constant region is encoded in the genome, and as such determinate like any other protein, the variable region is generated by a most unusual process referred to as rearrangement, involving cutting and pasting DNA.
The immunoglobulin's variable region binds antigen. An antigen is everything that is able to elicit an adaptive immune response. Its chemical composition is of minor importance. Antigens include, but are not limited to, polypeptides, carbohydrates, fats, nucleic acids and less frequently than commonly perceived synthetic materials. A certain minimum size is required. Very small molecules only function as antigens, so-called haptens, when coupled to larger carriers.
Antibodies recognize fairly large, three-dimensional surface structures. Any non-covalent binding force can be used to establish this contact: Antigen binding is therefore reversible. In most cases, a biological macromolecule contains several independent structures able to elicit an antibody response, so-called antigenic determinants or epitopes.
Conversely, two very different macromolecules which by chance share a certain three-dimensional structure may be bound by the same antibody, a phenomenon known as cross-reaction. All these statements refer to antigens bound by antibodies. Antigens recognized by T-lymphocytes are more narrowly restricted: If a certain protease is used to digest the Y-formed antibody, three fragments result: In early experiments, this fraction was successfully crystallized, giving the fragment the name Fc fraction crystallizable.
As this is the "back" end of an antibody, many cells of the immune system have receptors binding to it: The affinity of most of these receptors is too low to bind single, free antibodies for longer periods of time. Only after antigen-binding, resulting in larger immune complexes, cooperative binding between several Fc ends and their receptors leads to rapid internalization by phagocytosis, providing a mechanism for rapid antigen clearance.
Bacteria, viruses and parasites in general are antigenic. After a lag phase of at least five days, which we must survive with the help of innate immunity, B-lymphocyte-derived plasma cells will produce specific antibodies. These antibodies then bind to the pathogens. How does this help us? Depending on pathogen, antibodies can help by at least five different mechanisms: For example, these may be virus-infected cells exposing viral envelope proteins in their cell membrane.
Neutralizing viruses or toxins means studding them from all directions with antibodies, so that they are no longer able to make contact with their receptors. To enter a cell, each virus makes contact with one specific protein, which we call its receptor. Of course, the protein was not intended to be a virus receptor; it has some physiological function that is quite different.
For example, HIV human immunodeficiency virus misuses the lymphocyte transmembrane protein CD4 as its receptor. CD4 is important for lymphocyte functioning, which we will look at in section 2. For some viruses unfortunately not for HIV , it is possible to induce neutralizing antibodies, either by the infection itself or by vaccination. For example, vaccination against hepatitis B virus HBV is very effective. The vaccine contains recombinant envelope protein, HBs-antigen, and induces neutralizing antibodies.
If HBV later enters the body, it is immediately studded with antibodies. Unable to enter the liver cell, it remains completely harmless and is soon phagocytized and degraded. Some bacterial diseases, like tetanus or diphtheria, are not so much caused by the bacteria themselves, but rather by toxins they produce. These bacterial toxins also work by binding and misusing cellular proteins, directing the cells to do something that is in the interest of the bacteria.
Vaccinating babies with inactivated versions of these toxins produces neutralizing anti-toxin antibodies. If a child later is infected, it will not even notice, as the disease-causing toxins cannot bind to their receptors: Complement-activation via the classical pathway: IgM and two of the four subclasses of IgG activate complement. The Fc portion of these antibodies binds complement component C1q, with further steps unfolding as described in section 1.
Free soluble antibodies are not able to activate complement. How is this important, as complement is also activated via the alternative and lectin pathways? Antibodies make the process much more efficient: More complement pores are formed, with a better chance of bacterial lysis.
In addition, immunoglobulins are opsonizing in their own right, via Fc-receptors on phagocytes. Complement receptors are also important for immune complex-waste management. CR1 is not only present on leukocytes, but also on red blood cells, binding to C3b that has been deposited on immune complexes. With that, erythrocytes become the garbage truck for immune complexes, transporting them to spleen and liver, where phagocytes will take them off their backs.
If this transport system is overwhelmed, soluble immune complexes will deposit at sites of filtration, e. IgM is a pentamer consisting of five Y-formed units arranged in a circle. It is always the first immunoglobulin coming up in response to an infection, gradually declining afterwards.
The ability of IgM to activate complement is so strong that a single bound IgM-"crab" functions as a landing platform for C1q. This is different from IgG, where at least two IgG molecules have to bound at a distance allowing C1q to go in between.
By its size, IgM is mainly confined to blood plasma; it is simply too big to squeeze through between endothelial cells. IgG is the standard model antibody, appearing later during an immune response than IgM. IgG is the only class of antibodies transported across the placenta, equipping a newborn child for months with antibodies against pathogens "seen" by its mother.
Half-life of IgG in blood is approximately 21 days, about double that of IgM. IgG reach high molar concentrations in plasma, a prerequisite for effective neutralization of viruses or toxins. IgA , of which two subclasses exist IgA1 and IgA2 , can be found as a monomer in the blood, but its main function is to protect "outer" epithelial surfaces.
To get there, it has to be produced in the submucosa as a dimer joined by a J-chain. An epithelial cell, e. There, it is released by cleavage of the receptor. SC protects sIgA from proteolytic digestion in the intestinal tract.
Its strong glycosylation localizes and concentrates sIgA in the thin mucus layer lining the epithelium. There, sIgA prevents viruses, bacteria and toxins to make contact with their respective receptors by keeping them near the surface of the mucus lining, a mechanism termed immune exclusion.
IgE developed as a tool to fight parasites worms and protozoa. If a worm penetrates the epithelial barrier, it binds to and crosslinks specific IgE, resulting in mast cell degranulation. Additional IgE will bind to the parasite.
Mast cells release histamine and other molecules attracting eosinophils. An inflammatory reaction, induced via H1 receptors, facilitates the movement of eosinophils, which are guided in their chemotaxis by H4 receptors. In developed countries, parasite infections today are less common.
A problem arises when the immune system confuses innocuous entities such as inhaled tree or grass pollen with dangerous parasites.
Normally useful IgE then becomes a liability, inducing hay fever or bronchial asthma. IgD is found together with IgM on the cell membrane of newly produced B lymphocytes, and in negligible amounts in plasma.
Soluble IgD is not currently thought to have a function in defense. In patients, it is possible to measure concentrations of either an entire immunoglobulin class e. In the past, antigen-specific antibody concentrations were routinely expressed as a "titer". One typical example for such a vintage test would be the complement binding reaction, where upon the addition of a serum dilution and complement, test erythrocytes either lyse or don't lyse.
A patient's serum was diluted 1: If lysis was seen at dilutions 1: Frequently, it was expressed reciprocally: We will look at three of the numerous test systems to determine antibody concentrations: For all three, monoclonal antibodies are required.
Originally, simple antisera were used to detect specific biomolecules, including human antibodies. A laboratory animal such as a rabbit was immunized with the purified molecule in question example: Yet, such an antiserum, in lab jargon called "polyclonal antibody" is far from a precision tool. It contains a smorgasbord of antibodies against all antigens the lab animal has been in contact with.
These side specificities can completely distort the test results. A monoclonal antibody obviates the specificity problem, as it constitutes amplified replicas of a single antibody produced by a single B cell. However, generating a monoclonal antibody is a time-consuming and tedious procedure.
In the usual procedure, a mouse is repeatedly immunized with the antigen of interest, in our example human IgM. After several weeks of injections with human IgM, the mouse will produce antibodies against human IgM. Many of the B cells producing these antibodies will reside in the mouse's spleen, which is removed to get hold of these cells. At this point, it would seem straightforward to take these cells into culture and simply harvest the desired antibody, yet the cells would stop proliferating and die very soon.
To endow them with unlimited survival and proliferation potential, they are fused to a mouse tumor cell line that has exactly these properties. In addition, the tumor cells have a biochemical Achilles' heel that is later used to get rid of unwanted cells. Fusion of cells can be performed by a simple lab procedure using polyethylene glycol. It's the goal of the next step to have only the desired fusion cells survive.
Unfused or fused B cells are no problem- they die automatically after a few days. Unfused or fused tumor cells are a problem: To kill them, a trick is used. The tumor cell line is deficient in an enzyme important to recycle purine nucleotides, hypoxanthine-guanine phosphoribosyltransferase HGPRT.
To survive, the tumor cells constantly synthesize new purine bases, for which they need tetrahydrofolic acid. The trick is to block the regeneration of tetrahydrofolic acid by adding its antagonist aminopterin to the culture. Following fusion, the bulk of cells is cultivated in HAT -media, named for containing h ypoxanthine the recycling starting point , a minopterin and t hymidine which also could not be produced without tetrahydrofolic acid. Tumor cells die, as they are now completely unable to produce purine nucleotides.
B cells die anyway. After some time in culture, only these cells remain, which we refer to as hybridoma cells, implying a fusion cell that grows like a lymphoma. These represent all varieties of B cells originally present in the mouse spleen.
Many will not produce any antibody at all, many will produce antibodies unrelated to our antigen, and only few will produce high-affinity antibodies to human IgM.
How to find them and get rid of the others? The next step is limiting dilution: The volume is chosen in a way that statistically, there is only one single hybridoma cell in every other well. Whatever grows up will thus be monoclonal, meaning stemming from one single cell.
Hybridoma cells secrete their antibody into the medium, or culture supernatant. The last remaining challenge is to find the two, three or five cell clones producing antibody against our antigen among the hundreds or thousands of clones producing something else or nothing at all. For that, an immunological assay usually ELISA, see below is used with our antigen, human IgM, as a bait to test all culture supernatants for the presence of antibody binding it.
Once found, the hybridoma cell clone can be expanded and cultured virtually indefinitely, and monoclonal antibody can be purified from its culture medium in large quantities. Today, monoclonal antibodies against most diagnostically important macromolecules are commercially available. In addition, monoclonal antibodies are increasingly being used as drugs, e. However, as they mostly originate from the mouse, they would elicit an immune response in humans HAMA: Therefore, "humanized" monoclonals are used, where all parts of the mouse antibody not directly required for antigen binding are replaced by their human counterparts.
Antibody concentrations in patients' sera can be measured by many methods; the most common one is ELISA e nzyme- l inked i mmuno s orbent a ssay. To ascertain a recent infection with a specific virus, a test for IgM against that virus could be performed as follows. First, the wells of a microtiter plate are coated with virus or virus protein.
Then, the wells are incubated with diluted patient serum: After washing thoroughly, monoclonal mouse antibody against human IgM is added. This is the same antibody we produced in the previous section, but now has been linked to an enzyme such as horse radish peroxidase. If there was anti-virus IgM in the patient's serum, the enzyme-linked antibody will bind, too. If the serum contained no anti-virus IgM, the enzyme-linked antibody will be subsequently washed away.
Finally, a colorless substrate molecule is added, which is metabolized to a bright color pigment by horse radish peroxidase. The amount of color, proportionate to the amount of anti-virus IgM in the patient serum, is photometrically quantified. Color means the patient has IgM against the virus; no color means no anti-virus IgM is present. An analogous parallel test could be run using another monoclonal antibody against human IgG, to check whether the patient had been infected with the same virus a longer time ago.
Western blots are used, for instance, as a confirmation test to diagnose HIV infection. HIV proteins are denatured and solubilized using the detergent SDS, separated via a polyacrylamide gel and transferred to a paper-like membrane. This blot with bound virus proteins is then subjected to basically the same steps as described above for the virus-coated plastic well in the ELISA.
The membrane is first treated with diluted patient serum, then with an enzyme-linked monoclonal antibody against human antibody, finally with substrate, with washing steps in between. If the patient has antibodies against HIV, this will show in the form of colored bands on the membrane.
Sometimes, for instance in autoimmune disease, it is important to test whether a patient has antibodies against certain tissue structures, without knowing the exact molecule the antibody might recognize. To assay whether a patient has anti-nuclear antibodies, cells or a tissue section are applied to a glass slide and incubated with a droplet of diluted patient serum. If antibodies are present that bind to some nuclear structure, they can again be detected using a mouse monoclonal against human antibody, in this case coupled to fluorescent dye.
If the patient has antinuclear autoantibodies, the nuclei will be brightly visible in the fluorescence microscope; in the absence of ANA, they will remain dark. For an overview whether normal amounts of IgM, IgG and IgA are present in human serum, immunoelectrophoresis is informative.
First, serum proteins are separated electrophoretically in a gel. Then, rabbit anti-human serum is applied to a groove running in parallel to the axis of separation. The rabbit antiserum diffuses through the gel towards the separated human proteins. Precipitation arcs form where serum proteins and antibody meet, allowing to identify three separate arcs for IgM, IgG and IgA. In case of IgA deficiency, that specific arc would be missing.
How is it possible that we are able to form antibodies against virtually any antigen on the globe? Antibodies are made of polypeptide chains, and polypeptides are genetically encoded, yet the human genome only consists of approximately 25, genes.
Even if the majority of them encoded antibodies, that wouldn't do the trick by far. The answer to this conundrum has been found: The variable region of an immunoglobulin is formed by portions of both the heavy and the light chain. The variable portion of the heavy chain is not linearly encoded in the genome, bat rather in separated gene segments of three types, V, D and J v ariable, d iversity and j oining.
Importantly, each of these segments is present in multiple, slightly different variations: A complete heavy chain variable region exon is randomly cobbled together by juxtaposing one V, one D and one J segment by a cut and paste process at the DNA level.
Then, normal DNA repair proteins directly rejoin the segments. In all, there are 65x27x6 ways to recombine the segments, resulting in 10, different heavy chain possibilities just by rearranging the building blocks. But that is not all. The rejoining process is somewhat messy: This mechanism is called junctional diversity or imprecise joining.
Light chain genes are individually manufactured along the same lines, with the difference that they do not have D segments, just V and J segments. Combining randomly generated heavy with randomly generated light chains adds another level of variability. Somatic recombination is performed in immature B cell precursors in the bone marrow. Maintenance of a productive reading frame is monitored by specific quality control mechanisms.
Successful assembly of a heavy chain, for example, is signaled via a specific kinase, BTK Bruton's tyrosine kinase. In the absence of a BTK signal, implying frame shifts in both heavy chain genes, the now useless maturing B cell enters apoptosis. Once an entire antibody has successfully been assembled, it is expressed as a transmembrane protein in the form of a B cell receptor.
The difference between B cell receptor and secreted antibody is in a transmembrane domain, encoded by a separate exon, that can be added or omitted by alternative splicing. In the course of an adaptive immune response, especially if the antigen cannot be eliminated quickly, an additional mechanism adding to overall variability and allowing development of high-affinity antibodies comes into play: In B cells rapidly proliferating in germinal centers of lymphoid follicles, those regions within the rearranged VDJ heavy chain or VJ light chain exons that encode the protein loops making direct contact with the antigen undergo somatic mutation at a rate that is approximately thousandfold of normal.
These complementarity determining regions are therefore also called hypervariable regions. What is the mechanism behind this mutation rate? In all cells, one of the most frequent forms of DNA damage is spontaneous hydrolytic deamination of cytosine, resulting in uracil. AID is only active in genomic regions that are intensely transcribed, as the two DNA strands have to be slightly separated for the enzyme to work.
Deamination is equivalent to a point mutation: Some of these mutations will increase antibody affinity, and the respective B cells will be able to hold on to antigen for longer and consequently receive a stronger stimulus to proliferate. Somatic hypermutation over time thus favors a shift to antibodies of higher affinity.
In summary, four different mechanisms contribute to the generation of antibody diversity: Antibody diversity is thus caused by a DNA-based random generator. That seems kind of an oxymoron: How is it possible that a random generator develops in this rigid system? Comparing different species, we find that all vertebrates, from fish to man, use some form of RAG-based random generator to enhance defense against infections. Interestingly, a few primeval jawless fish species like lamprey and hagfish do not.
If we take a look at our genome, we do not find a sleekly designed, minimalistic high tech machine. Rather, it resembles a confusing accumulation of ancient sediments. Between and overlapping active genes, it contains many copies of "molecular nonsense machines" like retroviruses and transposons, most of them inactivated by mutations.
What do I mean by "molecular nonsense machines"? Imagine a contraption with the sole ability to produce copies of itself. Given sufficient resources, that would soon result in an avalanche of these machines.
Viruses, in principle, are nothing else. Another type of nonsense machine is a unit of DNA containing the information required to produce enzymes with the ability to excise the unit from surrounding DNA and implanting it elsewhere.
This is what we call a transposon. In the Silurian, to million years ago, the following genetic accident happened in a fish: Yet, it could still be healed if the transposon re-excised itself. This structure was the nucleus of our antibody- and T cell receptor-loci, which evolved by numerous locus doublings followed by mutational drift.
B and T cell receptors correspond to the original transmembrane protein, the RAG proteins to the transposon's nucleases. Usually, all that remained from the original transposon were its left and right demarcations for excision, short base sequences we now call recombination signal sequneces RSS.
Of all transposon copies, only one, on chromosme 11, maintains active nucleases: Once a variable region has been successfully generated by rearrangement, it can be handed down from one isotype to another. These cells now produce IgG, having undergone class switch. Note that the variable region has remained exactly the same. The antibody binds the same antigen with the same affinity, only it's now of the IgG isotype. Probability and type of class switch are influenced by cytokines released by T-lymphocytes and other cells.
Class switch occurs spatially and temporally parallel to somatic hypermutation, in the germinal centers of secondary follicles. Both processes are initiated by the same enzyme, AID. Gene segments for heavy chain constant regions have switch regions that easily form single chain DNA loops.
In these temporary loops, AID deaminates cytosine, leading to uracil. This is in fact a targeted and accelerated version of a process occurring regularly in our cells, spontaneous deamination by hydrolysis. Uracil in DNA constitutes a "wrong" base that is quickly eliminated by a dedicated repair system. If the same happens at the opposite strand a few nucleotides further down, a double strand break occurs.
In case of class switch recombination, this form of DNA cleavage occurs simultaneously at two distant locations. Isn't it dangerous to have antibodies generated randomly? One would expect some useful antibodies, depending on the type of infections encountered. But more antibodies are likely to be useless and some might be even dangerous, causing autoimmune disease if they by chance bind to structures of our own body.
B cell clones having rearranged antibodies recognizing ubiquitous self-antigens undergo apoptosis at an early stage clonal deletion or change into a "frozen" state from which they cannot be reactivated clonal anergy. However, these protective mechanisms do not work perfectly, sometimes allowing autoantibodies to be produced. The distinction between useful and useless antibodies is made by infecting pathogens.
New antibodies are rearranged all the time in newly developing B cells in the bone marrow. Once it is clear that they don't recognize frequent self-antigens, they migrate to peripheral lymphatic tissues and wait. Most wait in vain, and eventually die. In case of an infection, an invading pathogen will encounter a broad array of antibodies, sitting as "B cell receptors" on resting B cells in lymph nodes or other lymphoid tissue.
If one out of a million of B cell receptors fits an antigen of the pathogen, this specific B cell is induced to proliferate, while all other B cells don't react. This is called "clonal selection": The difference between B cell receptor and secreted antibody is a transmembrane domain at their terminus of the heavy chain that is included or excluded by alternative splicing.
As our immune system is constantly engaged fighting subliminal infections, there are a lot of "useful" proliferating B cells at any point in time. Thus, the proportion of useful B cells among the total is actually higher than expected from the randomness of antibody generation.
Antibodies are sharp-edged tools, always involving the risk of autoimmune damage. It would be extremely dangerous if a single contact between B cell receptor and antigen were sufficient to unleash large-scale antibody production.
Therefore, in analogy to a gun, the release of a "safety catch" is required as a safeguard before a B cell can be activated. This is accomplished by a complex process summarily designated "T cell help". An exception to this rule are so-called T cell independent antigens. In many cases, these are linear antigens with repetitve epitopes which are able to crosslink multiple B cell receptors or additional pattern recognition receptors.
This activation merely leads to production of IgM, usually of modest affinity. Neither class switch nor affinity maturation is possible in the absence of T cell help. To understand how T cells function and interact with other cells, some information on lymphoid tissues and organs, T cell receptor and MHC is required.
In the bone marrow, hematopoietic stem cells give rise to lymphoid progenitor cells. From these, B cells differentiate in the bone marrow, although the name B cell is derived from a gut-associated organ in birds, the b ursa Fabricii , that doesn't exist in humans. Lymphoid progenitors also migrate to the t hymus located on top of the heart , where they undergo complex quality assurance procedures that allow only a small fraction of these thymocytes to leave the thymus as mature naive T cells explained in section 2.
Lymphocytes travel mainly via the bloodstream. APC leave the bloodstream to widely roam tissues. Eventually, all types of cells meet again at the peripheral lymphatic organs: LYMPH NODES seem static in the microscope, but should better be compared to the transit area of a big international airport, with oodles of cells arriving and leaving all the time. Lymph nodes have several inlets and an outlet. Afferent lymphatic vessels reaching the most peripheral lymph nodes transport the interstitial fluid filtrated from blood capillaries.
With the lymph flow, dendritic cells loaded with ingested material drift to the lymph nodes, e. In case of an infection, lymph flow increases dramatically, carrying with it pathogens and their antigenic molecules, outside and inside of activated macrophages and dendritic cells. Thus, a lymph node is a local command center with continuous real-time information on the antigenic situation in the periphery.
India ranks a low out of countries in the Environmental performance Index This report is produced by the researchers of Yale and Columbia University in association with the World Economic Forum. Environmental pollution is a serious problem of the industrialized societies. The industrial development and the Green Revolution have adversely affected the environment.
People have converted the life supporting system of the entire living world into their own resources and have vastly disturbed the natural ecological balance.
Serious degradation and depletion have been caused due to the overuse, misuse and mismanagement of resources to meet the human greed. Environment pollution is defined as the unfavorable alteration of our surroundings. These changes could be in the physical chemical or biological characteristics of land air or water that harm human life and other living things. Population explosion, rapid industrialization deforestation unplanned urbanization scientific and tech logical advancement etc.
The major causes of environmental pollution. Nearly 35 percent of India total land area is subjected to serious environmental pollution. Three fourths of the earth consists of water yet there is scarcity of potable water. In India allay the sources of water lie rivers lakes ponds and wells have been polluted and are unfit for drinking. As a result of the increased use of fertilizers, the rivers seas and oceans have become contaminated with harmful pollutants.
Industrialization has led to urbanization. The migration of rural population to the cities in search of work has created an unhealthy environment. It has led to overcrowding and establishment of slum areas. Towns and cities are full of smoke ,fumes dirt dust rubbish gases foul smell and noise.
Nuclear explosions and nuclear tests also pollute the air. The spread of radioactive materials into the air has increased. This radioactive pollution may cause cancers, abnormal births and mutations in men.
The Taj Mahal in Agra is affected by the fumes emitted by the Mathura refinery. Reports estimate that the monument would get defaced within a span of twenty years because of the harmful effluents of the emission from the refinery. Water pollution adversely changes the quality of water. It disturbs the balance of the ecosystem and causes health hazards. Water becomes polluted by the presence or addition of inorganic and organic or biological substances.
Industrial effluents which are dumped into the rivers further add to the water pollution levels. Soil pollution usually results from the disposal of solid and semi solid wastes from agricultural practices and from insanitary habits. The soil gets heavily polluted by hazardous materials and micro organisms, which enter the food chain or water and create numerous health problems.
The emission of greenhouse gases has led to climatic changes. The increase in pollution has resulted in global warming. Global warming is an average increase in the Earth temperature due to greenhouse effect as a result of both natural and human activity. The term climate is often used interchangeably the term global warming. The ice caps in the polar regions have begun to melt fast. This has resulted in the rise of the water level of the seas and oceans.
Grass sprouting in Antarctica and snowfall in the desert of the united Arab emirates are all the warning signals of global warning. Pollution causes different types of diseases. Air pollution causes allergies asthma lung cancer and bronchitis.
Radioactive pollutants cause respiratory problems paralysis cancer and other disease. Excessive noise pollution can lead to deafness anxiety stress increase in the rate of heartbeat and other health problems.
In order to fight this menace of pollution vigorous efforts should be made the anti pollution law should be strictly implemented. In order to check water pollution sewage and the factory waste should be planted everywhere and vehicles should be made eco friendly. Public education and awareness of the relationship between climate change and human health is a key to deal with these problems more effectively.
General awareness is a must to save our planet from destruction. A ll the nations of the world should work united to control environmental pollution. Plato lamented the destruction of soils and forests in ancient Greece.
Dickens and Engels wrote eloquently of the wretched conditions spawned by the Industrial Revolution. But the surge in concern about environmental quality over the last three decades has been uniquely widespread and impassioned. Appreciation of the material and spiritual importance of a healthy natural environment has spread. Perhaps the most dramatic intellectual shifts are occurring in the Third World, where understanding of the ecological under spinning of human life-largely lost in the post-war dreams of industrialisation is on the rise.
The new interest in environmental quality complements recent shifts in thought among development theorists, many of whom now stress the need to address the basic needs of the poor directly rather than hope that the benefits of growth will trickle down to them.
Improving the lot of the under-class and protecting environmental quality can be mutually-supportive goals. Both internationally and within nations, the new appreciation of our bonds with nature has spawned new institutions and policies-new UN and governmental agencies, new laws, altered aid programmes, new international treaties.
Yet for the most part, responses remain inadequate to the needs. For the most urgent need today is to protect and preserve what remains of the environment. To do that one has to understand the meaning of pollution and consider ways of tackling it. It takes place through changes in energy patterns, radiation levels, chemical and physical constitutions, and abundance of organisms.
It includes release of materials into atmosphere which make the air unsuitable for breathing, harm the quality of water and soil, and damage the health of human beings, plants and animals. Air pollution in one form or another has accompanied human society from the beginning. In the nineteenth and early twentieth centuries, many cities of Europe and the US were covered with black shrouds of smoke.
Despite the successes registered against smoke, the pollution of city air by other products of coal combustion above all, Sulphur dioxide and by nitrous oxides, hydrocarbons, petroleum wastes, and carbon mon.
Strong evidence indicates that prevailing levels of air pollution contribute to the development of chronic respiratory diseases emphysema, asthma, and chronic bronchitis besides short-term respiratory afflictions as well. And those living near smelters and refineries often face increased cancer risks because of the toxic substances spewing from smoke-stacks. Over the last 25 years, many countries have begun trying to regulate the flow of pollutants in the air, Air pollution can no longer be addressed as simply a local urban problem.
Thermal pollution of water. In general, pollution from so-called point sources like sewage pipes and factories is under progressively better control. But the contamination of waterways from diffuse sources-run-off from farmlands which tends to carry fertilizers, pesticides, and organic matter, and from urban areas, which often carries oil, metals, and other pollutants-remains largely uncontrolled and is on the increase in most countries. Acids and heavy metals falling with the rain constitute additional sources of water degradation.
The problem of water pollution is growing day-by-day; today a great many people are deprived of disease-free potable water, as almost all the sources of water-from seas to wells-are increasingly being infested with different kinds of pollutants.
Soil pollution usually results from the disposal of solid and semi-solid wastes from agricultural practices and from insanitary habits. Fallouts from atmospheric pollution also contribute to soil pollution. Direct pollution of the land by pathogenic organisms is also important. Thus the soil is heavily polluted day-by-day by hazardous materials and micro-organisms, which enter the food chain or water and are consequently ingested by man.
As a result, there are numerous health problems. Those bacteria which are transmitted from air to soil infect man causing bacillary dysentery, cholera, typhoid and paratyphoid fever. Flies which breed or get in contact with the contaminated soil become carriers of disease organisms. The eggs of some of the parasitic worms get incubated in the soil and both the eggs and larvae are infective. Radioactive pollution of the environment is due to the increase in natural background radiation, emerging from the activities of man involving the use of naturally occurring or artificially produced radio-active materials.
The chances of radioactive materials Spreading into the air have increased extensively as a result of the discovery of artificial radio-activity, and particularly due to the development of atomic bomb and of techniques of harnessing nuclear energy. Biological organisms including human beings are subjected to radioactive contamination either by consumption or inhalation.
Chronic exposure to radiation leads to leukemia in an individual and affects even an unborn child. Thermal pollution denotes the impairment of the quality of environment air or water by a rise in its temperature.
The processes of life involve many chemical reactions, and the rate of these chemical reactions vary according to the changes in temperature. Apart from biochemical reactions, temperature is considered vitally important to physiology and in controlling reproductive cycles, digestion rates and respiration rates. The effects of thermal pollution are mainly seen on aquatic animals, particularly fish, on whom the human society so much depends.
The modern world has a new pollution to face-that of noise. The scientific approach for considering noise as a pollutant is by decibel. Apart from industrial noises the sources generally are loudspeakers, motor vehicles, trains, aircrafts, processions and rallies.
Noise need not just lead to deafness. Research has shown that noise pollution is capable of causing ulcers, abortions, cardiovascular diseases, congenital defects and hypertension.
The first and most important cause of pollution is the growing population. The earth is now crowded with people, and all of them consume resources and create wastes. If the per capita amounts of pollutants and wastes were to remain constant, the residue loading of the environment would rise precisely in relation to the growth of population. This is acceptable within certain limits, given the capacity of air, water and land to absorb, dilute, carry away and otherwise render pollutants harmless.
But, unfortunately, in many places these limits have either been reached or have been exceeded. Another important factor is the rapid industrialisation and haphazard urbanisation all over the world.
The natural processes which keep the planet habitable in the short-term are primarily cyclic. Materials moving through these cycles utilise solar energy and return to their original state before other processes start. In contrast, modern technology causes materials to be removed from the limited geological deposits or from living systems to be eventually discharged as wastes. Not only do these wastes act as pollutants of the natural cycle but they also alter the composition of the atmosphere and disturb the balance of solar radiation.
The ability of the biosphere to withstand these stresses is further decreased by such conversion of complex natural ecosystems to simple ones. Haphazard urbanisation makes it quite difficult to provide and maintain the required civic amenities. Some cities have become so large and so crowded that the municipalities fail to properly maintain the sewage, provide clean drinking water or adequate garbage removal facilities.
The deterioration of natural systems in poor and marginal areas is at once a symptom and a cause of the extreme misery in which hundreds of millions live. The pollution problems cannot be isolated from questions of economic progress, political stability, social awareness, migration and international aid.
Indeed, many types of localised environmental degradation have global implications. To some degree their causes are also international. Through their way of life and the behaviour of their multinational corporations, citizens of the North can affect environmental conditions in the South. More important, the extent of the extreme poverty that gives rise to so much ecological damage and human suffering is influenced by international monetary, trade, technological and aid policies.
The struggle to preserve global environmental quality is unavoidably intertwined with the struggle to improve the lot of the global under-class. The problems are rooted in the society and the economy-and in the end in the political structure, both national and international. Foresters know how to plant trees, but not how to devise methods whereby villagers in India, the Andes, or the Sahel can manage a plantation for themselves.