Pesticide Residues in Man - Pesticides: Evaluation of Environmental Pollution - page 491

Carreño et al. (2007) monitored the levels of 14 OCPs in the blood of 220 young males
(mean age: 20.75 years) in Southern Spain. Aldrin, dieldrin, endrin, lindane, methoxychlor,
endosulfans, and DDT and its metabolites were identified. Detectable concentrations of
p,p′-DDE were found in 96% of serum samples. Among the remaining DDTs, o,p′-DDD
was the most prevalent, detected in 65% of serum samples. Detectable concentrations of
endosulfan I or II or their metabolites endosulfan diol or endosulfan sulfate were found
in all the samples; endosulfan diol was the most frequently detected metabolite (92%), fol-
lowed by endosulfan sulfate. Results indicate that men of reproductive age in Southern
Spain have been and are exposed to OCPs. HCB, dieldrin, endosulfan sulfate, and p,p′-
DDT levels were associated with the mother's employment in agriculture during preg-
nancy. On the other hand, the ratio of p,p ′ -DDT to p,p ′ -DDE, which may indicate whether
the exposure was in the distant (low ratio) or recent (high ratio) past, was estimated at 0.7
in their study. This ratio suggests the influence of the restriction and prohibition of DDT
and the decrease in exposure to these compounds over the past few decades.
Also in Southern Spain, another study (Lopez-Espinosa et al. 2008) was conducted to
assess the presence of 16 OCP residues in 52 fat samples collected from boys with a mean
age of 7 years (0-15 years). No pesticide was found in more than 50% of the samples,
except for p,p′-DDE (79% of the samples; median, 710 ng/g lipid). After this compound,
the most frequent pesticides were o,p ′ -DDT (17%; median, 330 ng/g lipid) and o,p′-DDD
(15%; median, 1510 ng/g lipid). No statistically significant association was found between
p,p′-DDE or ∑DDTs and the birth year, birth weight, gestational age, infant feeding his-
tory or the age, weight, height, or Quetelet Index at the time of sampling. The lack of
correlation between the presence of the main metabolite, p,p′-DDE, and that of the par-
ent compounds, o,p′-DDT and p,p′-DDT, suggests that children were exposed mainly
to the metabolite rather than to the commercial pesticide, which was banned 30 years
ago. By contrast, among the currently used OCs, endosulfan was positively correlated
with the presence of its metabolites, suggesting exposure to the commercial products.
In this respect, it may be useful to mention that children can be exposed to OCPs in
utero via the placenta (Lopez-Espinosa et al. 2007) and after birth via lactation (Solomon
and Weiss 2002) and infant formula (Cressey and Vannoort 2003). Diet is an important
potential route of pesticide exposure in older children (Patandin et al. 1999). Children
are especially vulnerable to pesticide exposure because they consume a larger amount
of food and water relative to their body weight as compared with adults. Also, the types
of food consumed by children differ from those consumed by adults, that is, children's
diet contains more milk products and more fruits and vegetables (Bearer 1995), which
are known sources of exposure to fat-soluble or persistent and less persistent pesticides,
respectively. Infants may also bear additional exposure risks because of their tendency
to explore their environment with their mouths, their closeness to the ground, and the
longer time they spend playing outdoors (Garry 2004; Bearer 1995). Finally, the develop-
ing organ systems of children are more sensitive and their bodies have a limited ability
to detoxify pesticides (Bearer 1995).
Table 15.6 shows data of OCP residues in the blood of 220 young males aged 18-23 years
(Carreño et al. 2007) and in the adipose tissues of 52 boys aged 0-15 years. (Lopez-Espinosa
et al. 2008).
Porta et al. (2008) reviewed the adverse effects of POPs on human health and the impact
of policies aiming to reduce human exposure to POPs, which warrant monitoring the body
concentrations of POPs in representative samples of the subjects. While numerous ad hoc
studies are being conducted to understand the effects of POPs, only a few countries con-
duct nationwide surveillance programs on human concentrations of POPs, and even lesser