Pesticide Residues in Man - Pesticides: Evaluation of Environmental Pollution - page 485

100

93.5

90

Urban population
Rural population

80

70

60

50

43.9

40

30

22.3

20

19.8

17.4

20

14.8

13

10

7.3 7.5

6.3 6.3

10

2.5

0

∑HCHs ∑DDTs HCB Aldrin Dieldrin HE Endosulfan

sulphate

Detected pesticides

FIGURE 15.7
Mean concentration (μg/L) of organochlorine pesticide residues in human serum samples from urban and rural
populations in Portugal. ∑HCH includes α-, β-, and γ-isomers. ∑DDT includes p,p′-DDE, p,p′-DDD, o,p′-DDT,
and p,p′-DDT. HE, Heptachlor epoxide. (Adapted from Cruz, S., Lino, C., and Silveira, M. I. 2003. Evaluation of
organochlorine pesticide residues in human serum from an urban and two rural populations in Portugal. Sci.
Total Environ. 317: 23-35.)

higher than mean total HCH levels, and HCH levels were slightly higher in rural popu-
lation, while all the other estimated pesticide residues were higher in urban than rural
population (Figure 15.7). This situation can be due to higher consumption of animal-origin
foods and dairy products by urban population (DeVoto et al. 1998). According to Cruz et al.
(2003), Portugal imports animal- and vegetable-origin foods from Asia and Latin America
where DDTs are still in use. Urban populations preferentially consume these imported
products, once they have higher accessibility to this kind of products, while rural popula-
tions tend to consume the products they grow.
Focusing on the data illustrated in Figure 15.8 , it appears that the levels of total HCH and
total DDT tend to be higher in men than in women either in urban or rural Portuguese pop-
ulation. Other studies, in Germany, Japan, and Senegambian region, also reported higher
levels of HCH isomers in males (DeVoto et al. 1998; Hanaoka et al. 2002). Studies conducted
in the United States, Belgium, and Egypt (Ahlborg et al. 1995; Charlier and Plomteux 2002;
Soliman et al. 1979) have also reported mean total DDT levels in men higher than those in
women. According to Cruz et al. (2003), such results could suggest that lactation is a route
of excretion, as there are studies that indicate the transfer of OC residues to breast milk
(Waliszewski et al. 1999b). Even OP-toxic residues, such as chlorpyrifos, have shown to be
transferred through lactation to suckling rats (Mansour and Mossa 2010).
Previous reports established a relationship between age and OC residue levels (Stehr-
Green et al. 1988; Soliman et al. 1979; Voorspoels et al. 2002). Figures 15.9 and 15.10 illus-
trate the total concentration levels of HCHs and DDTs in urban and rural populations in
Portugal (Cruz et al. 2003). The latter investigators reported that younger groups have
higher levels of detection of the analyzed OCP residues, causing suspicion that exposure
to pesticide residues continues to happen.