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Planned Water-related Research Activities

Investigation to Assess Risk Factors for Well Water Contamination after Flooding

Investigation to Assess Risk Factors for Well Water Contamination after Flooding

Objective: To assess risk factors for well water contamination after flooding.

Background: About 15% of the US population, or nearly 50 million people, obtains their drinking water from sources not protected by the Safe Drinking Water Act, such as private wells. CDC recently reported that the percentage of waterborne disease outbreaks associated with these unregulated sources of drinking water is increasing. Even when well-constructed and maintained, wells are at risk for contamination from flooding. Wells can become contaminated by human pathogens such as Escherichia coli O157:H7, Giardia, Cryptosporidium, and enteric viruses, nitrates from fertilizer, and pesticides applied on nearby lands. There is minimal information about which characteristics of flooding events are the most important risk factors for well contamination. This project looks at contaminants in flood water to assess their potential public health significance.

Methods: In May 2010, Nashville, TN experienced significant flooding following heavy rainfall. HSB staff traveled to Nashville in May to collect 10 floodwater samples, and subsequently in June and August, 2010 to collect well water samples from flooded and non-flooded wells. In April 2011, Kentucky experienced significant flooding. From May 1–4, at team worked with the Kentucky Department of Public Health (KDPH) to collect flood water samples from 4 different affected regions of Kentucky. From July 25–26, a team collected follow-up surface water samples from these same locations.

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Comparing Contaminant Exposures in Local Dolphin Populations to those in People Eating the Same Local Seafood

Comparing Contaminant Exposures in Local Dolphin Populations to those in People Eating the Same Local Seafood

Exposure to contaminants in fish, dolphins, and humans

Objective: We are conducting three pilot studies to see whether dolphins can be sentinels for exposure to and accumulation of environmental contaminants in human populations that share the same coastal resources.

Background: Small fish eat smaller marine animals. Bigger fish eat smaller fish. Dolphins eat bigger fish. Sharing the top of this marine food chain with dolphins are people who also eat fish. Environmental contaminants that accumulate in the marine food chain put human populations at risk for exposure. Common environmental contaminants found in the marine environment include chemicals such as polychlorinated biphenyls (PCBs), dioxins, and chlorinated pesticides. These compounds linger in the environment long after production or use has ended and they accumulate in the fat of marine life and people.

Methods: We conducted pilot studies in three locations – northern Biscayne Bay, FL; Charleston Harbor, SC; and Sapelo Island, GA to see if people who eat locally caught fish have similar exposures to dolphins that eat the same fish. In each location, we asked questions, collected seafood meal samples, and took blood samples of nine people who ate seafood caught in local waters at least twice a week. We plan to compare the levels of chemicals measured in these 27 individuals with levels found in their seafood meals and with levels found in dolphins that live nearby.

Results: Data analysis is planned to be completed and published during 2015. For more information see our Sapelo Fact Sheet [PDF - 255 KB]

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4 Villages: Investigation of Unregulated Water Use and a Household Survey in 4 Rural Alaskan Villages

4 Villages: Investigation of Unregulated Water Use and a Household Survey in 4 Rural Alaskan Villages

Objective: 1. To characterize water quality in various surface drinking water sources and other unregulated water sources in four rural Alaska villages; 2. To characterize drinking water quality in homes; 3. To evaluate household water source, use, storage and handling practices to assess public health risks and develop appropriate public health education messages; and 4. To determine if water hauling behaviors or water contamination risks vary between summer and winter seasons.

Background: The use of unregulated drinking water sources represents a potential public health risk for communities with these water sources not routinely treated or tested for biological or chemical contaminants. Though some rural Alaskan villages are being connected to regulated community water, many villages still rely on water hauling from unregulated water sources for their drinking water. This study will take a comprehensive look at water quality and contamination drinking water sources used by four select Alaskan villages which will include rivers, wells, tundra ponds, and other surface water sources.

Methods: We worked with the Alaskan Native populations, CDC Arctic Investigations Program, Alaska Native Tribal Health Consortium (ANTHC), and the local communities during a two-week field study in both March and August, 2010. Both of these data collection periods were preceded by a training we developed to prepare the 14 individuals participating in our field teams with the understanding and technical expertise to conduct work in the villages.

This study investigated unregulated drinking water sources used for drinking water sources near the four selected villages. These water sources were sampled and tested for a panel of inorganic chemicals, concentrations of persistant organic chemicals (e.g., PCBs, dioxins, chlorinated pesticides), and microbial contaminants (e.g. total coliforms, E. coli, Cryptosporidum, Giardia, norovirus, enterovirus, and Salmonella). The regulated water treatment facility in each village was also tested for all of the above contaminants for comparison. A household survey was also conducted to include all 300 households within the four villages. At each household a sample of water from each drinking water source used by the household was collected. These water samples will be analyzed for inorganic chemicals and bacterial contamination (total coliform and E. coli). In addition, one adult in each household was interviewed regarding drinking water source, use, and handling practices, knowledge and beliefs regarding water safety, and self-reported health effects. The household surveys were conducted in close collaboration with ANTHC and the local community supervisor for each village. This study was repeated in 5 villages in both the summer and winter seasons using the same population for comparison.

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Evaluation of Water Cistern Contamination and Health Risks in the Navajo Nation

Household Survey of Drinking Water Sources and Contaminant Exposures at the Navajo Nation

Investigation of Drinking Water exposures in Unregulated Water Sources at the Navajo Nation

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