2007-07-18 03:50:42 · 12 answers · asked by akar integral 2 in Environment ➔ Other - Environment
Sure...what is the question!
2007-07-18 03:58:37 · answer #1 · answered by Geno 2 · 0⤊ 0⤋
So to repeat answer to same question:
The problem with "pollution" is that it is understood in so many different ways. Some people think pollution is the same as contamination but it is not. Scientifically just about everything is contaminated meaning that it is not a pure chemical or pure substance but is a mix of desirable and undesirable components. When you barbeque a beefburger you actually form toxic and harmful substances on the surface by burning some of the fat. Ironically, this mixture of burnt fat and protein is what makes it taste so good and people continue to eat and enjoy such "contaminated" food without coming to harm. It really all a question of degree. Small quantities of contamination in air, water, soil, food are inevitable. There is only one chemical known which is 100% man-made and not naturally occurring. That is PCB or polychorinated biphenyl. Everything else occurrs naturally and we are exposed to "harmful" chemicals all day every day. Now some of us are more resistant to exposure than others in the same way as some of us are genetically more susceptible to disease than others. There is therefore no single level or quantity where something is 100% safe. There is always a risk. Pollution is considered to be a level of contamination which significantly increases that risk to the extent that "normal" life is obstructed.
Take the example of dissolved oxygen levels in fresh water - streams, lakes etc. Water is saturated with oxygen at about 10 mg/l. It varies with temperature but we can take 10 as a benchmark figure. Once a stream has formed, there will always be some contamination with substances which consume the dissolved oxygen so many streams and rivers actually balance out at 6 to 8 mg/l. As oxygen is consumed by the contamination, more oxygen is dissolved from the air to maintain normal aquatic life. Fish and other organisms can mostly tolerate oxygen levels down to 6 easily and down to 4 with some difficulty. When the oxygen level falls below 4 then some species do not do well and if it drops to less than 1 then only a few species can survive. Therefore in general terms we would tolerate an actual level of 6+ mg/l in a river and call it unpolluted but we would be concerned at <6 mg/l and would call that water polluted.
Same goes for air quality, soil quality and so on and so forth.
2007-07-19 04:19:52 · answer #2 · answered by oldhombre 6 · 1⤊ 0⤋
Just try to explain in your own words, what you think causes pollution, i.e - big power stations belching out , car exhaust fumes, the getting rid, by cutting down the trees in the rain forests, etc, also people not doing enough to recycle, and in general too much waste from people being selfish. hope this is what you want. just try your best that is all you can do.
2007-07-18 11:00:42 · answer #3 · answered by ROBERT M 4 · 0⤊ 0⤋
You haven't told us what the question is. It sounds like you haven't bothered to try for yourself. Have a go first and then ask for help if you really need it.
2007-07-18 11:02:13 · answer #4 · answered by Zoe S 3 · 0⤊ 0⤋
Well, whats the question.
2007-07-18 10:55:12 · answer #5 · answered by Mr. Cadillac Jones 2 · 0⤊ 0⤋
You forgot to ask the question.Thanks for the easy two points
2007-07-18 13:03:16 · answer #6 · answered by Yafooey! 5 · 0⤊ 1⤋
global warming
2007-07-21 17:55:48 · answer #7 · answered by william m 1 · 0⤊ 0⤋
If it's homework, you should do it yourself. Otherwise, you learn nothing.
2007-07-18 11:15:16 · answer #8 · answered by jdkilp 7 · 0⤊ 1⤋
Your right you do need help.
2007-07-18 11:00:16 · answer #9 · answered by wwgiese 2 · 0⤊ 0⤋
Please let us know the question! Then we might be able to help!
Or try google it yourself: http://en.wikipedia.org/wiki/Pollution
2007-07-18 10:54:27 · answer #10 · answered by grpr1964 4 · 0⤊ 0⤋