Pesticide Residues in Man - Pesticides: Evaluation of Environmental Pollution - page 498

The workers spraying methomyl, a carbamate insecticide, showed significant ECG
changes, indicating cardiotoxic effect of methomyl (Sayed et al. 1992). In addition to imbal-
ances in the immune system, various kinds of skin diseases including pigmentation on the
exposed parts have been reported in the workers handling pesticides (Sharma et al. 1986).
Data on reproductive toxicity collected from 1106 couples engaged in spraying of OC,
OP, and carbamate insecticides in cotton fields and from unexposed workers (1020) gave
the following reproductive performances for the former and the latter groups (Rupa et al.
1991): (a) Abortions (26% vs. 15%); (b) Still births (8.7% vs. 2.6%); (c) Neonatal deaths (9.2%
vs. 2.2%); and (d) Congenital effects (3% vs. 0.1%).
A cytogenetic study revealed a significant increase in chromatid breaks and gaps in the
chromosomes in the peripheral blood in the grape garden workers exposed to pesticides
(Rita et al. 1987). The workers spraying HCH, DDT, malathion, and cyfluthrin for malaria
control showed increased levels of serum IgG (malathion exposure) and serum IgA (cyflu-
thrin exposure) (Karnik et al. 1993).
In another study, the thyroid function of the formulators exposed to a combination of
pesticides in the organized sector was examined. Total T3 was significantly suppressed in
the formulators, while a marginal decrease (7%) was noticed in the T4 level. The TSH lev-
els were also elevated by 28%, but the rise was statistically insignificant (Zaidi et al. 2000).
These formulators had significantly low serum cholinesterase activity and high serum
BHC content, indicating appreciable exposure to their working environment.
Twenty blood samples randomly selected from four different villages of Punjab were
analyzed for 14 OCs and 14 OP pesticides by Mathur et al. (2005). The results revealed
that the total number of pesticides detected in the blood samples from Punjab was 15 out
of the 28 pesticides analyzed, which indicated that each person is exposed to and carries
a body burden of multiple pesticides due to a combination of direct and indirect expo-
sure to these pesticides. The total OCP residues accounted to approximately 0.14 mg/L,
of which total DDT metabolites reached approximately 0.065 mg/L. Total OP pesticide
residues accounted to approximately 0.23 mg/L, of which monocrotophos recorded the
highest concentration level (~0.095 mg/L) among the other three detected OP pesticides
(chlorpyrifos, malathion, and phosphamidon) (Table 15.8). The authors concluded from
their study that human pesticide residue is a biological index of pesticide exposure and

TABLE 15.8
Organochlorine and Organophosphorus Pesticide Residues (mg/L) in Human Blood
Samples from Villages of Punjab, India
Organochlorines

Organophosphorus

Pesticide/Metabolite Concentration Pesticide/Metabolite Concentration

t-HCH 0.057 Chlorpyrifos 0.0662

Heptachlor 0.0006 Malathion 0.0301

Aldrin 0.0062 Monocrotophos 0.0948

Dieldrin ND Phosphamidon 0.0366

Chlordane 0.009 Total OPs 0.2278

t-DDT 0.0652

t-Endosulfan 0.0046

Total OCPs 0.1424

Source: Adapted from Mathur, H. B., Agarwal, H. C., Johnson, S., and Saikia, N. 2005. Analysis of pesticide

residues in blood samples from villages of Punjab. CSE/PML/PR-21/2005, 41, Tughlakabad
Institutional Area, New Delhi 110062, pp. 21 + Annex III.