Articles - Arsenic and chromium in hair samples from Woburn, MA
of Zurich who died in 1360 (19)] suggest that As in hair may be used as a biomarker, even in samples that are several hundred years old. Although similar studies of the Cr content of historic hair samples have not been reported, it has been demonstrated that Cr within hair strands in not easily removed, even upon washing with shampoos and organic solvents (20); thus, it is reasonable to expect that Cr levels in decades-old hair sam- ples will reflect the levels at the time Cr was initially incorporated in the hair. The rela- tionship between As and Cr in hair and drinking water has been demonstrated in studies in which populations exposed to ele- vated levels of As and Cr in their drinking water were found to have significantly higher concentrations of these elements in their hair than control populations (21-24).
19 years; the remaining samples were from adults over 19 years of age.
Elemental analysis. To distinguish ele- ments incorporated in the hair during growth from those that were deposited on the outside of hair strands, the samples ini- tially were washed with both acetone and
water according to a hair cleaning proce- dure described elsewhere (25). After drying in a fume hood at room temperature, the samples were irradiated with a thermal neu- tron flux of 8 x 1012 n/cm2/sec for 12 hr. The samples were then cooled for 2-3 days, washed again with acetone, and transferred
In this study we compared As and Cr concentrations measured in the hair of Woburn residents with estimates of each donor's access to water from wells G and H. We posited that if As and Cr were present in the well water, then individuals consum- ing the water would have incorporated As and Cr into their hair in proportion to the amount of well water consumed. We used instrumental neutron activation analysis to determine the As and Cr concentrations of the hair samples, a model of the Woburn water distribution system to estimate access to wells G and H, and linear regression analysis to determine whether As and Cr concentrations in hair samples were depen- dent upon access to well water in a statisti- cally significant manner.
Hair collection. The samples used in this study were obtained from Woburn resi- dents who saved locks of hair cut from their children or themselves before, during, and/or after the period when wells G and H were in use. The samples, many of which had been stored in photograph albums and scrapbooks, were placed indi- vidually in air-tight polyethylene bags and transported to the laboratory for analysis. For each sample, the donor's sex, age, and address at the time the hair was cut were recorded, as were the month and year of the haircut. For 14 of the samples collected between 1964 and 1979, the month that the hair was cut was not known so only the year was recorded. A total of 82 samples were collected, representing 56 donors and 34 different residences. Twenty-six of the samples were cut between 1938 and 1963, 36 were cut between 1964 and 1979 (the period during which wells G and H were in operation), and 20 were cut between 1982 and 1994. Seventy-two samples were from children between the ages of 1 month and
Figure 1. Map of the Aberjona watershed.
Superfund site boundary
Environmental Health Perspectives * Volume 105, Number 10, October 1997