Journal of Water and Health Vol 07 No 2 pp 185–207 © IWA Publishing 2009 doi:10.2166/wh.2009.073

There appears to be very good epidemiological evidence for a relationship between chlorination
by-products, as measured by trihalomethanes (THMs), in drinking water and bladder cancer,
but the evidence for other cancers, including colorectal cancer appears to be inconclusive
and inconsistent. There appears to be some evidence for a relationship between chlorination
by-products, as measured by THMs, and small for gestational age (SGA)/intrauterine growth
retardation (IUGR) and preterm delivery, but evidence for other outcomes such as low birth
weight (LBW), stillbirth, congenital anomalies and semen quality appears to be inconclusive
and inconsistent.
The overall aim of the HIWATE study is to investigate potential human health risks (e.g. bladder
and colorectal cancer, premature births, SGA, semen quality, stillbirth, congenital anomalies)
associated with long-term exposure to low levels of disinfectants (such as chlorine) and DBPs
occurring in water for human consumption and use in the food industry. The study will comprise
risk–benefit analyses including quantitative assessments of risk associated with microbial
contamination of drinking water versus chemical risk and will compare alternative treatment
options. The outcome will be improved risk assessment and better information for risk
management. The work is divided into different topics (exposure assessment, epidemiology, risk
assessment and management) and studies.
Key words | cancer, chlorination, disinfection by-products, epidemiology, reproductive health, risk
assessment