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Some of the reasons I don't spray pesticides ...
sherwindu wrote:
Glenna Rose wrote: [major snippage] [] They have scared people to death about getting cancer from chemicals, and know they can charge big bucks if they just stick the 'organic' label on their produce. Organic certification can be a long arduous process. The requirements are stringent (at least here in Canada). So, are you saying people don't get cancer from chemicals? How naive you appear to be. Yes, people who don't wash their produce properly. However, there is usually a much reduced amount of chemicals on fruit, since the sun burns most of it off. Are you sure about that? Then how come they keep finding it in fruit ... among other things? ------------- POPs found in all foods: wvlc.uwaterloo.ca/biology447/modules/ module5/Jepidemilologyarticle/pesticidesinfoodpdf.pdf [] Based on data from the US Food and Drug Administration, this article provides a brief overview of POPs residues in common foods in the United States food supply. The analysis focuses on 12 chemical compounds now targeted for an international phase out under the Stockholm Convention on POPs. The available information indicates that POPs residues are present in virtually all categories of foods, including baked goods, fruit, vegetables, meat, poultry, and dairy products. Residues of five or more persistent toxic chemicals in a single food item are not unusual, with the most commonly found POPs being the pesticides DDT (and its metabolites, such as DDE) and dieldrin. Estimated daily doses of dieldrin alone exceed US Environmental Protection Agency and US Agency for Toxic Substances Disease Control reference dose for children. Given the widespread occurrence of POPs in the food supply and the serious health risks associated with even extremely small levels of exposure, prevention of further food contamination must be a national health policy priority in every country. [] -------------------------------- Yes, but previous contributors to the thread opened up this aspect that these chemicals affect the whole world. In actual fact, they do. Here's why. If someone in India dumped DDT into the ocean, how long do you think it would take to get to the Gulf of St. Lawrence? Would you believe less than 2 weeks? It's called The Grasshopper Effect (http://www.ec.gc.ca/science/sandemay/article2_e.html), and it's just one of the ways that toxics travel around the world. This is why DDT, which has been banned in NA since the 70's, is still found in the belugas of the St. Lawrence. This is why they constantly need to replenish the Peregrine Falcons in the wild release programs. Pesticides (and/or their breakdown products) that were used from the 40's to the 70's are still out there in the food chain. Pesticides permeate every body of water on the planet and are highly detrimental to aquatic life: http://rainbow.ldgo.columbia.edu/edf/text/ddt.html [] Worldwide, levels of DDT are between 1 and 10 ng/l in estuaries and coastal areas, and between 0.1 and 1 ng/l in the open sea (Kennish, 1994). While DDT concentrations in surface waters are largely controlled by the concentration of DDT in the atmosphere, the ocean serves as a sink for DDT (Iwata et al., 1993). [] In the Arctic, the highest concentrations of DDT in surface waters are reported near the Indigirka River in the East Siberian Sea (2.5 ng/l) and in the vicinity of the Ob' River in the Kara Sea (2 ng/l, Melnikov and Vlasov 1992). DDT in belugas generally ranges from 1 to 5 ug/g in the Alaskan and Canadian Arctic (Muir et al., 1990; Careau et al., 1992; Schantz et al., 1993). Note that these values are about 1 million times higher than DDT levels in seawater. An average of 58 ug/g was measured in belugas from the St. Lawrence estuary, a high value indicative of past heavy use of DDT as a pesticide in eastern Canada (Muir et al., 1990). New data indicate that the White Sea is similar to the St. Lawrence estuary, with a value of 64 ug/g (Muir and Norstrom, 1994). [] Once ingested, DDT and its metabolites accumulate in the fatty tissues of organisms. Today, birds and mammals continue to retain both DDD and DDE, in part from retention in fat, and in part from uptake of residual contamination. An important concern with DDT is that it becomes concentrated as it is transferred up the food chain. In an aquatic environment, DDT at a concentration of 0.001 to 0.01 ppb (- or m? check), results in a 0.1 ppm concentration in aquatic invertebrates, 0.2 to 2 ppm in fish, and 10 ppm in birds (Edwards, 1973). Because pesticide residues can be transferred to offspring through excretion in the egg, progeny may begin life with an elevated body burden of DDT. [] --------------------------------------- More about Belugas and pesticides: http://ehp.niehs.nih.gov/members/199...uise-full.html Overhunting in the 1rst half of the century was the probable cause for this population to dwindle from several thousand animals to the current estimate of 500. The failure of the population to recover might be due to contamination by organochlorine compounds, which are known to lead to reproductive failure and immunosuppression in domestic and laboratory animals and seals. [snip] Overall, St. Lawrence belugas might well represent the risk associated with long-term exposure to pollutants present in their environment and might be a good model to predict health problems that could emerge in highly exposed human populations over time. -- Environ Health Perspect 103(Suppl 4):00-00 (1995) ---------------------------------- Organochlorine levels in whales tissue samples from Trent University: http://whale.wheelock.edu/bwcontaminants/results.html ---------------------------------- Global Pesticide Release Database from Environment Canada: http://www.msc-smc.ec.gc.ca/data/glo...nowledge_e.cfm [] Organochlorines, which are stable and vapour-forming, can be carried by air currents for long distances. Eventually they condense and are deposited on land and water, particularly in cold climatic regions. Oganochlorine residues have been detected in air, water, soil, sediment, fish, and birds global wide. They have also been found in remote areas, such as open oceans and polar regions. If they contaminate the food supply of animals, organochlorines become more concentrated as they move up through the food chain. For this reason, the highest levels of organochlorines are found in species at the top of the food chain: human beings, fish-eating birds, and marine mammals. [] ----------------------------- POP's such as aldrine, dieldrine, endrine, chlordane, DDT, heptachlore, hexaclorobenzene, mirex, chlordecone, lindane, and toxaphene, build up in tissues. ---------------- wvlc.uwaterloo.ca/biology447/modules/ module5/Jepidemilologyarticle/pesticidesinfoodpdf.pdf All living organisms on Earth now carry measurable levels of POPs in their tissues. POPs have been found in sea mammals at levels high enough to qualify their bodies as hazardous waste under US law, and evidence of POPs contamination in human blood and breast milk has been documented worldwide. There is strong evidence that exposure to even miniscule amounts of POPs at critical periods of development— particularly in utero—can cause irreversible damage. The effects of such exposures may take years to develop, sometimes appearing first in the offspring of exposed parents. [] ----------------- As we are at the top of the food chain, humans get the most concentrated doses of contaminants. Among whales, the females are less toxic than the males. Studies revealed that the reason for this is that females release the toxins from their fatty tissues into their milk. (http://whale.wheelock.edu/bwcontaminants/results.html) It's the same for humans. There are also indications that, due to their interactions inside the body, pesticide cocktails can be more toxic than the same amount of a single pesticide. ---------------------------------- Oraganochlorines in human breast milk: http://oregonstate.edu/instruction/bi301/pesthist.htm DDT (as DDE, a breakdown products from DDT) also appeared in the fatty tissues of seals and Eskimos, far from any area of use, indicating that, because of its persistence, it was being transported for long distances in the atmosphere and then being washed from the atmosphere by rains. It also showed up in human breast milk at remarkably high concentrations -- so high that the milk couldn't legally be sold through interstate commerce if it were cow's milk! DDE is the most widespread contaminant in human milk around the world. When you think about it, human breast fed babies are way up there on the food chain, and are thus very susceptible to the effects of biomagnification and bioconcentration. For persistent compounds like DDT (or other persistent compounds, such as dioxins or PCB's -- see "POPs," below) human milk is the most contaminated of all human foods. Typically, concentrations of organochlorines (such as DDT) in human milk are 10 - 20 times higher than in cow's milk, and prevailing levels are often greater than those allowed in commercial food stuffs. [] ----------------------------- http://ca.water.usgs.gov/pnsp/rep/fs09200/ Human exposure to organochlorine pesticides has been documented by studies detecting these compounds in various human tissues, including breast milk. Consumption of contaminated food (including fish and shellfish) is a major route of human exposure to organochlorine pesticides. [] Organochlorine compounds tend to be stored in high-fat tissues within the body, but can be mobilized during lactation or starvation. Levels of some organochlorine compounds in human tissues in the United States do not appear to have declined, at least through the early 1980s. Examples include DDT in breast milk and dieldrin in adipose tissue (fat). [] --------------------------------- Body stores of pesticide are also associated with breast cancer: http://www.breastcancerfund.org/site...70679&ct=90190 So why is there that much pesticide in the environment? Who's using it all? Trends in Pesticide Use: "One major environmental science text book asserts that the average US homeowner uses 2 - 6 times more pesticide per acre than do farmers." http://oregonstate.edu/instruction/bi301/pesttren.htm [] We will focus on farms, because farmers consume (that is, use) about 77% of all pesticides in the US. However, it is important to realize that the problem isn't all related to farm uses. It is estimated that about 10% of the land area in the US (including forests, lawns, etc.) is treated annually with pesticides. Home gardeners are often some of the most extravagant ? and sloppy ? users!) (One major environmental science text book asserts that the average US homeowner uses 2 - 6 times more pesticide per acre than do farmers.) In the US, the total pounds of pesticide active ingredients applied on farms increased 170% between 1964 and 1982 (the increase was 33 fold between 1945 and 1990). These figures related only to the agricultural sector. In evaluating these increases, it is important to remember the increased toxicity of pesticides; one pound of active ingredient for current products is many times greater than one pound for earlier generations of pesticides in terms of toxicity. One might think that this trend was driven by increasing agricultural acreage over this time? Recall, during this time, total acres under cultivation basically decreased , so the increase in pesticide use wasn't driven by increased agricultural acreage. [] ------------------------------ So, obviously, more is less. http://www.nationmaster.com/graph-T/env_pes_use In the US, an average of 1599 kg of pesticide are used for each hectare of cropland, that's 3525 lb per hectare. 1 hectare= approx. 2.5 acres, so that makes it about 1,410 lbs of pesticide per acre. So if home gardeners are using just twice that amount, it comes to 2,820 lbs of pesticide per acre. If they all stopped using pesticides, it would be a significant amount not going into the environment. This group is about the home gardener, not about major farming conglomerates, or undeveloped countries that do not have irrigation available and other such advantages that lead to good production. There's a lot more to famine than pesticide spraying. No amount of pesticide will control the locust infestation plaguing parts of Africa today. And ... That good irrigation is what gets pesticides into the water table: Pesticides in Ground Water: http://ca.water.usgs.gov/pnsp/pestgw...2001_Text.html ------------------------- Pesticides found in all the bodies of water on the planet. http://ca.water.usgs.gov/pnsp/index.html ------------------------- PESTICIDES ANALYZED IN NAWQA SAMPLES: Use, Chemical Analyses, and Water-Quality Criteria http://ca.water.usgs.gov/pnsp/anstrat/index.html#t3 ------------------------- Like everything else, pesticides can be misused. The evidence suggests that they ARE being misused. And the more they're misused, the less effective they'll be. And too often are. I have neighbors that use them as a matter of course. I never have and have no problem with undesirable bugs. Probably because the pesticides are acting in your yard as well. They're easily airborne. I truly believe each of us can make a difference, and do, good or bad. Glenna That is irrefutably true. :-) For people who persist in spraying, IPM is the better way. Spraying can be cut in half using IPM methods. Better for the environment, the pocket book, and the back. An entomologist, who works at the big research station near here developing IPM protocols for peaches, told me that the main reason for IPM is that bugs adapt too readily to pesticides. Pesticides work really well for a few years and then start to be less effective as the bugs adapt. The big worry is soon there won't be any pesticides that work. IPM strives to keep pesticide use to a minimum, so that when it is used, it works. The added bonus for growers is lower cost, and better yield. IPM borrows from successful organic principles, such as predatory control, and the proper timing of applications. Now that the life cycles of pest insects are better understood, controls (natural or otherwise) can be tailored to be more effective. That's why I try to learn about every single new bug, or problem, that I find. For instance, I found out the plum curculios like the cool, dampness and lack of sun in the middle of the tree. I checked my tree, and the plums on the outside, that get sunshine through most of the day are the healthiest. I think I need to prune my tree to get more light into the middle ... now all I have to do is learn more about proper plum tree pruning. EV |
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