Paper No. 5
Presentation Time: 9:30 AM
CONCENTRATIONS OF TCE AND OTHER TOXICS DELIVERED TO THE PLAINTIFFS' HOMES IN THE 'A CIVIL ACTION' TRIAL
In the 1986 federal trial described in the book and movie A Civil Action, the plaintiffs alleged that contamination from two properties was captured by municipal wells G and H in Woburn, Massachusetts and ingestion of the toxic chemicals caused severe health effects including childhood leukemia. A recent epidemiologic study showed a positive association between gestational exposure to water from wells G and H and the occurrence of childhood leukemia. The study used a water distribution model to estimate the water from wells G and H delivered to residences across the city. Temporal variations in the concentrations of TCE and PCE produced by wells G and H are not included in the study. To provide insight into the possible TCE and PCE exposures at residences across the city and at each plaintiffs residence between 1964 and 1979, when wells G and H periodically operated, we linked the results of a contaminant transport model to the water distribution model. The water distribution model, which divided the city into water districts and accounted for mixing with uncontaminated water supplied by six wells in other parts of the city, calculated the monthly fraction of water from wells G and H that each water district received, which varied spatially and temporally across the city due to management of pumping rates and schedules in the eight municipal wells. To estimate TCE + PCE concentrations likely delivered to residences, simulated concentrations of TCE and PCE in wells G and H from the contaminant transport model were multiplied by the fraction of water contributed from wells G and H to each water district. TCE and PCE exposure histories for the 54 water districts indicate that more than 4000 residences likely received concentrations of TCE + PCE exceeding the 5 ppb. Many residences likely received concentrations of TCE + PCE greater than 5 ppb for more than 100 months. The gestational TCE + PCE exposure histories of the mothers of the seven plaintiff children indicate that six of the women were exposed to TCE + PCE and that the degree of exposure varied greatly depending on the date of birth, the water district in which they lived, and the concentrations of TCE and PCE produced by wells G and H during the time of gestation. The results suggest that the worst exposures likely were in the range of several hundred ppb TCE + PCE for several continuous months.