Pesticide Residues in Man - Pesticides: Evaluation of Environmental Pollution - page 482

outlines the general picture of these pollutants in different foodstuffs. Seafood con-
tained the highest level of DDTs (4726 ng/g lipid weight), while the highest level of HCB
(199 ng/g lipid weight) was found in tea leaves. Based on the authors' report, DDT and
its metabolites were prominent compounds in most of the foodstuffs. In particular, mus-
sels contained noticeable residues of DDTs (34,000 ng/g lipid weight), which are one to
three orders greater than the reported levels in the bivalves in other Asian countries.
Concentrations of HCHs, CHLs, HCB, and PCBs in foodstuffs were generally low, sug-
gesting small amounts of inputs into the environment. Considering that foodstuffs are a
main source of human exposure to contaminants, the greater concentrations of DDTs and
HCHs in Chinese people might be due to extensive usage of these compounds as agricul-
tural pesticides in the past. Continuous monitoring and epidemiological studies of OCPs
in humans are warranted in China.
In Mexico , eighty human abdominal adipose tissue samples from Veracruz and 80 sam-
ples from Puebla were analyzed and the obtained results were compared among both pop-
ulations (Waliszewski et al. 2010). The results from Veracruz showed higher contamination
levels (mg/kg on lipid base) compared with Puebla: β-HCH: 0.072 versus 0.029; p,p′-DDE
(dichlorodiphenyldichloroethylene): 2.364 versus 0.726; o,p′-DDT: 0.022 versus 0.025; p,p′-
DDT: 0.192 versus 0.061; and ∑-DDT: 2.589 versus 0.806. The population of Veracruz and
of Puebla divided by sex, origin, and cause of death presented no statistical differences.
The comparison between sexes (women and men groups) in Veracruz and Puebla indi-
cated significantly higher levels in Veracruz and resulted in statistically significant dif-
ferences. Calculating possible risks (odds ratios, ORs), p,p′-DDE (OR = 5.04) and o,p′-DDT
(OR = 2.93) revealed a significantly higher risk for the Veracruz population. The study
indicated prolonged DDT exposure of Mexicans caused by its sanitary use in the past and
the persistence of its residues in soil and air.
15.4 Pesticide Residues with Respect to Human
Sociodemographic Characteristics
This issue has been partially demonstrated in Section 15.3. More data on age and race
effects, ethnic differences, social classes, and geographical variations are given below.
Although most human exposure to OCPs can probably be linked to dietary contamina-
tion, other factors, such as age (Zumbado et al. 2005), gender (Lino and da Silveira 2006;
Petrik et al. 2006), lifestyle (Deutch et al. 2003), and type of habitat (Zumbado et al. 2005;
Lino and da Silveira 2006; Petrik et al. 2006), have been reported to be good predictors of
OC levels in human populations.
The public health risks of pesticides depend not only on how toxic various compounds
are, but also on how many people are exposed, what their risk-related demographic, socio-
economic, and health profiles are, what kinds of pesticides they are exposed to, and the
extent and routes of exposure (WRI 1996). Four large groups are potentially exposed to
pesticide hazards: (1) Farmers and farm workers; (2) Workers and laborers in pesticide
factories; (3) Populations that live in areas of intensive pesticide use or production; and (4)
Populations exposed to persistent pesticides that bioaccumulate in food. Groups within
the general population that can be exposed to high levels of bioaccumulated pesticides
include (1) Habitual consumers of fish, livestock, and dairy products; (2) Fetuses and
nursing infants whose mothers' bodies have accumulated substantial levels of persistent