Pesticide Residues in Fish - Pesticides: Evaluation of Environmental Pollution - page 362

TABLE 13.1
Common Side Effects of Pesticides

Environmental Component Side Effects

Abiotic Residues in soil, water, and air

Plants Presence of residues, phytotoxicity, vegetation changes

(due to the use of herbicides)

Animals, birds, insects, etc. Residues, physiological effects, mortality in certain wild

life species, mortality of beneficial predators and
parasites, insect population changes (outbreak of
secondary pests), genetic disorders

Man Biochemical changes, residues in tissues and organs,

effect of occupational exposure, mortality and
deformations

Food Presence of the residue

resulted in serious health implications to man and his environment. There is now over-
whelming evidence that some of these chemicals do pose potential risk to humans and
other life forms and unwanted side effects to the environment (Table 13.1).
No segment of the population is completely protected against exposure to pesti-
cides, and the potentially serious health effects, though a disproportionate burden, are
shouldered by the people of developing countries and by the high-risk groups in each
country.
Ideally, a pesticide must be lethal to the targeted pests but not to the nontarget spe-
cies, including man. Unfortunately, this is not the case. So the controversy of use and
abuse of pesticides has surfaced. The rampant use of these chemicals, under the adage,
“if little is good, a lot more will be better,” has played havoc with human and other
life forms.

13.1.2 Adverse Effects of Pesticides

Carson in 1962 warned that organochlorine (OC) compounds could pollute the tissues
of virtually every life form on the earth, the air, the lakes, and the oceans, including the
fish that live in them and the birds that feed on the fish. Later, the US National Academy
of Sciences stated that the DDT metabolite DDE causes eggshell thinning and that the
bald eagle population in the United States declined primarily because of exposure to
DDT and its metabolites. Organochlorine pesticides (OCPs), which act in a similar way
as natural hormones, may lead to disorders of the endocrine system in animals and
humans (endocrine disruptors) (Trudeau and Tyler 2007) and reduction in reproduction
of animals and humans (Hart et al. 2003; Henny et al. 2008). Gregoraszczuk et al. (2008)
reported a stimulatory effect of environmental organic contaminants extracted from the
liver oil of Atlantic cod on testosterone, 17β-estradiol, and progesterone secretion by por-
cine ovarian follicular cells. Golec et al. (2003) observed morphological abnormalities in
sperm as well as decreases in sperm count, percentage of viable sperm, and fecundity
rate in male humans exposed to pesticides. Endocrine disruptors are being increasingly
implicated in infertility, menstrual irregularities, spontaneous abortions, birth defects,
endometriosis, and breast cancer (Bhatt 2000). Many studies indicate that OCPs may
damage the immune system and cause defects in the male reproductive system, low
sperm concentration, and increased incidence of cancer (Porta et al. 1999; Taylor and
Harrison 1999; Abell et al. 2000).