Pesticide Residues in Man - Pesticides: Evaluation of Environmental Pollution - page 493

1200

DDTs
PCBs
HCB
β-HCH

1000

800

600

400

200

0

BMI (kg/m 2 ) Gender Age (yr) Occup. class Educational level

Sociodemographic characteristics.

FIGURE 15.15
Serum concentration of POPs in Catalan (Spain) population by sociodemographic characteristics. Note:
DDTs = (p,p′-DDT and p,p′-DDE). PCBs = (PCB congeners No. 118, 138, 153, and 180). BMI, body mass index.
Occupational classes I, II, and III are nonmanual workers, and classes IV and V are manual workers. Educational
level: WFE, without formal education; Primary I and II: first and second primary schooling stages. (Data refer
to Porta, M., Gasull, M., Puigdomènech, E., et al. 2010. Distribution of blood concentrations of persistent organic
pollutants in a representative sample of the population of Catalonia. Environ. Int. 36: 655-664.)

interindividual differences were up to 7700-fold. POP levels differed significantly by gen-
der, age, BMI, educational level, and parity (Figure 15.15). The authors concluded that
exposure to POPs remains common, a vast majority of the population has much lower
blood concentrations than a relative minority, and the population distributions of POP
are hence highly skewed to the right. Shifting distributions toward lower concentrations
requires more energetic policies and population strategies.
The blood serum of the cacao farmers and their domestic water sources were analyzed
for insecticide residues in selected cacao growing communities of Southwestern Nigeria
(Sosan et al. 2008). The farmers were grouped into five exposure periods based on their
years of involvement in insecticide application: <5 years, 5-9 years, 10-14 years, 15-19
years, and >20 years. The residue analyses revealed that 42 out of the 76 farmers had
residues of diazinon, endosulfan, propoxur, and lindane in their blood; and 47.6% out
of these farmers belonged to the >20-year exposure period. About 34% of the farmers
had diazinon with a mean concentration of 0.067 mg/kg, 29% endosulfan (mean = 0.033
mg/kg), 23% propoxur (mean = 0.095 mg/kg), and 17% lindane (mean = 0.080 mg/kg) in
their blood ( Figure 15.16 ). The residues of lindane, endosulfan, and propoxur in all the
exposure duration categories were found to be far below the no observable adverse effect
level (NOAEL), while diazinon residues detected in the blood serum of the farmers in
all the exposure duration categories exceeded the NOAEL of 0.02 mg/kg for the insecti-
cide. The authors concluded that cacao farmers in Southwestern Nigeria may have been
occupationally exposed due to insecticide application for mired control in their cacao
plantations; and the exposure at times was of such magnitude so as to be hazardous to
the farmers and their respective communities.