Pesticide birds

Once OPs enter the body, they are mainly metabolized in the liver, gastrointestinal tract, malpighian tubulc.s, and body fat by mixed function oxida.ses, which further increase their toxicity. Oxidative desulfuration of OPs leads to maximum anticholincstera,se activity. To consider the possible toxic effect of OPs, it is necessary to take into account the type of chemical and the species in question because there are wide differences. For example, in vertebrates, after one. single exposure to OP pesticides the recovery time from the amicholincsicrase effecl-s ranges from I to 3 weeks, whereas only approximately 1 day is necessary to recover from exposure to a CM pesticide. Birds and mammals have similar metabolic responses to anticholinesterase pesticides. However, birds tend to be more sensitive to their toxic action, probably due to lower levels of metabolizing enzymes. 

The effects of pollution can be direct, such as toxic emissions providing a fatal dose of toxicant to fish, animal life, and even human beings. The effects also can be indirect. Toxic materials which are nonbiodegradable, such as waste from the manufacture of insecticides and pesticides, if released to the environment, are absorbed by bacteria and enter the food chain. These compounds can remain in the environment for long periods of time, slowly being concentrated at each stage in the food chain until ultimately they prove fatal, generally to predators at the top of the food chain such as fish or birds. 

The detrimental effect of organochlorine pesticides on reproductive success in birds of prey is well established following the crash of some populations during the 1950s and 1960s. Links have been established with the DDT metabolite, DDE, the cyclodiene pesticides and Although many raptor species... 

Although eggshell thinning attributable to DDE exposure has occurred in birds in the UK, the lethal and siiblethal effects of the cyclodiene pesticides aldrin, dieldrin and heptachlor are also believed to have contributed to the population effects, particularly in the case of the sparrowhawk and peregrine falcon. Following the withdrawal of DDT and the cyclodienes from use in the UK, Europe and North America, bird of prey populations that were severely affected have shown partial or complete recovery. ... 

Prohibit the advertisement, supply, storage and use of pesticides unless they have been approved. Pesticides includes herbicides, fungicides, wood preservatives, plant growth hormones, soil stenlants, bird or animal repellants. 

Despite the use of 2.5 million tons of pesticide worldwide, approximately 35% of potential crop production is lost to pests. An additional 20% is lost to pests that attack the food post-harvest. Thus, nearly one-half of all potential world food supply is lost to pests despite human efforts to prevent this loss. Pesticides, in addition to saving about 10% of world food supply, cause serious environmental and public health problems. These problems include human pesticide poisonings fish and bird kills destruction of beneficial natural enemies pesticide resistance contamination of food and water with pesticide residues and inadvertent destruction of some crops. 

As explained in Section 5.2.3, p,p -DDE is much more persistent in food chains than either p,p -DDT or p,p -DDD, and dnring the 1960s when DDT was still extensively used, it was often the most abundant of the three compounds in birds and mammals found or sampled in the field. Since the widespread banning of DDT, very little of the pesticides has been released into the environment, and p,p -DDE is by far the most abnndant DDT residue found in biota. While discussing the ecological effects of DDT and related compounds, effects on population numbers will be considered before those on popnlation genetics (gene frequencies). 

Fry, D.M. (1995). Reproductive effects in birds exposed to pesticides and industrial-chemicals. Environmental Health Perspectives 103, 165-171. 

Hart, A.D.M. (1993). Relationships between behaviour and the inhibition of acetylcholinesterase in birds exposed to organophosphorous pesticides. Environmental Toxicology and Chemistry 12, 321-336. 

Koeman, J.H. (Ed.) (1972). Side Effects of Persistent Pesticides and Other Chemicals on Birds and Mammals in the Netherlands. Report by the Working Group on Birds and Mammals of the Committee TNO for Research on Side Effects of Pesticides. TNO-Nieuws 27 527-632. 

Peakall, D.B. (1985). Behavioural responses of birds to pesticides and other contaminants Residue Reviews 96, 45-77. 

Ratcliffe, D.A. (1970). Changes attributable to pesticides in egg breakage frequency and eggshell thickness in British Birds. Journal of Applied Ecology 7, 67-107. 

Walker, C.H. (1983). Pesticides and birds— mechanisms of selective toxicity. Agriculture, Environment, and Ecosystems 9, 211-226. 

Walker, C.H. (2003). Neurotoxic pesticides and behavioral effects upon birds. Ecotoxicology 12, 307-316. 

Risebrough RW. 1986. Pesticides and bird populations. Curr Omithol 3 397-427. 

Studies may be designed for estimating exposures to a wide array of wildlife, including birds, mammals and amphibians. Many regulatory requirements involve birds, and less emphasis is currently placed on other species. As regulatory requirements evolve, ecological risk assessments will be required for more species. This may require alternative approaches for food item analysis to allow estimates of pesticide ingestion. 

Distributions of pesticide concentrations in potential food items for avian species are required to estimate the contribution of food to exposure of birds in different regions where the test chemical may be used. On treated fields, detectable CEF residues were found in 102 of 207 earthworm samples. No earthworm samples collected from control fields (N = 28) contained detectable CEF. Average CEF concentrations in earthworms reached maxima 1-4 days post-application (Table 3). Mean CEF residues in earthworms fell below 0.1 qg g after 8 days post-application. This... 

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