Pesticide Residues in Man - Pesticides: Evaluation of Environmental Pollution - page 477

TABLE 15.3
Pesticide Residues a in Urine Samples Collected from Adult American Citizens b

The 95th Percentile
Concentration ( μ g/L)
2,5-Dichlorophenol 98 790
2,4-Dichlorophenol 64 64
1-Naphthol 86 43
2-Naphthol 81 30
3,5,6-Trichloro-2-pyridinol 82 13
Pentachlorophenol 64 8.2
4-Nitrophenol 41 <6
2,4,5-Trichlorophenol 20 <6
2,4,6-Trichlorophenol 9.5 <6
2,4-Dichlorophenoxy acetic acid 12 <6
2-Isopropoxyphenol 6.8 <6
7-Carbofuranphenol 1.5 < 6
Source: Adapted from Hill, R. H., Jr., Head, S. L., Baker, S., et al. 1995. Pesticide residues in urine
of adults living in the United States: Reference range concentrations. Environ. Res. 71:
99-108.
a Number of targeted analysts: 12.
b Number of subjects: 1000.

Pesticide/Metabolite Frequency (%)

analytes were frequently found: 2,5-dichlorophenol (in 98% of adults); 2,4-dichlorophenol
(in 64%); 1-naphthol (in 86%); 2-naphthol (in 81%); 3,5,6-trichloro-2-pyredinol (TCPY) (in
82%); and pentachlorophenol (in 64%). The 95th percentile concentrations (95th PCs) for the
above metabolites were 790, 64, 43, 30, 13, and 8.2 μg/L, respectively. The 95th PCs for other
analytes were found to be less than 6.0 μg/L (Table 15.3). Exposure to p-dichlorobenzene
is ubiquitous; naphthalene and chlorpyrifos are also major sources of pesticide exposure.
Exposure to chlorpyrifos appears to be increasing. Although pentachlorophenol exposure
is frequent, the exposure appears to be decreasing. The obtained reference range of con-
centrations provides information about pesticide exposure and serves as a basis against
which concentrations in the subjects who may have been exposed to pesticides can be
compared.
A total of 1146 American inhabitants took part in a voluntary investigation for measur-
ing pesticide residues in their urine (Heudorf and Angerer 2001). All of them stated that
they had never used chlorpyrifos in their homes. Spot urine samples of the study par-
ticipants were analyzed for six metabolites of OP insecticides (dimethylphosphate (DMP),
diethylphosphate (DEP), dimethylthiophosphate (DMTP), diethylthiophosphate (DETP),
dimethyldithiophosphate (DMDTP), and diethyldithiophosphate (DEDTP)) using a very
sensitive gas chromatographic method with mass-selective detection and a limit of detec-
tion of 1 μg/L. No evidence of increased internal exposure due to former chlorpyrifos
application was found either in children or in adults in these homes (>4 years ago). The
median values and 95th percentiles of the urinary metabolite concentrations in 484 adults
were (μg/g creatinine) as follows: DMP: 15.5 and 102.5; DMTP: 13.5 and 125.8; DMDTP: <1
and 13.1; DEP: 2.1 and 11.6; DETP: <1 and 6.4; and DEDTP: both <1. The urinary metabolite
concentrations in children less than 6 years of age were higher; this was caused mainly
by lower creatinine concentrations. To conclude, no increase in the internal exposure due
to former indoor application of chlorpyrifos was found, and the reference values pub-
lished for internal OP exposure in adults in Germany were confirmed. However, as shown