Cancer risk and drinking water quality

Arsenic is a known contributor to the development of bladder and kidney cancer yet is commonly found in Nova Scotian well water due to that province's geology. By comparing data on Nova Scotia's cancer rates and arsenic exposure in drinking water, Dr Parker hopes to give policy-makers more accurate information about the actual risk of cancer development due to arsenic in well water. Project summary: Arsenic is known to cause kidney and bladder cancer when consumed in large enough quantities. Arsenic is a material that occurs naturally in some rock types. Arsenic present in rocks can enter drinking water supplies, especially if drinking water is obtained from a drilled or dug well. This research will use a variety of techniques to estimate potential exposure to arsenic in drinking water in Nova Scotia. Dr Parker's team will use this information to assess cancer risk in relation to this arsenic exposure. Previous research: Previous research shows that arsenic is a Class 1 cancer-causing material. However, most studies that have investigated the risk of cancer in relation to arsenic in drinking water have looked at areas where arsenic exposure is very high. The risk of cancer in relation to arsenic levels in drinking water that are around the national acceptable limit guidelines of 10 micrograms per litre is not well understood. One particular problem associated with these types of studies is that measuring arsenic exposure and arsenic consumption is difficult. Project description: Dr Parker's team will use existing cancer incidence and case-control data to provide an estimate of the geographic distribution of bladder and kidney cancer in Nova Scotia. They will use existing well water data in Nova Scotia to estimate arsenic exposure and use data on drinking water sample and toenail clippings from another study to estimate the relationship between arsenic in study participant's bodies and their drinking water (from a sample of Nova Scotia residents). They will link the cancer data to these different measurements of arsenic exposure in Nova Scotia residents to identify how much bladder and kidney cancer in Nova Scotia is influenced by arsenic in drinking water. Impact and relevance: Arsenic is known to cause cancer and it is a material that is commonly found in drinking water in Nova Scotia that is obtained from water wells. Other areas of Canada and elsewhere in the world that have the same geology as Nova Scotia also have problems with arsenic in drinking water. Public and environmental health policy requires accurate information about the health risks of environmental pollutants to ensure that legislation and environmental controls protect human health. In Nova Scotia private waters wells that supply nearly half of the population with drinking water are not regulated and do not have to be tested for arsenic. By establishing how high the risk of bladder and kidney cancer is in relation to arsenic in drinking water, this study will have an impact on population health by ensuring that government and health specialists are aware of the impact of this risk factor - a risk factor that can be dealt with by treating water supplies using appropriate technology.