The objective of this study was
to provide an improved exposure assessment for the reanalysis of two well-conducted,
peer-reviewed epidemiology studies that reported an increased risk of bladder cancer
associated with chlorinated drinking water and THMs in Iowa and Ontario. An improved
exposure assessment would provide more complete information on THMs plus haloacetic
acids (HAAs), including class sums and individual species, formed during chlorination
and alternative disinfection processes. Because bladder cancer has a long latency period,
up to several decades, historical DBP data (back to 1900 in Iowa and to 1940 in Ontario)
were required for the reanalysis. Historical databases contain very limited DBP data, and
there are no estimates for past DBP occurrence prior to the mid-1970s. Although THM
data have been collected routinely since the 1980s, most utilities did not start measuring
HAAs until the 1990s. Therefore, this research proposes that, through models and
correlations, it is possible to estimate past DBP levels based on present trends and
knowledge about changes in source water/treatment practices, in both the present and
past. Such estimates can provide an improved exposure assessment for the reanalysis of
epidemiology studies, such as the Iowa and Ontario studies.
Includes 4 references, tables.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 270 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 9 |
| Published : | 11/01/2002 |
