Improving data quality in community-based seafood consumption studies by use of two measurement tools.

A seafood consumption study w as conducted in Glynn County, Georgia, to address concern about bioaccumulation of mercury from a nearby hazardous waste site in people who ate potentially contaminated seafood from this area. Seafood consumption levels were ascertained with two data collection tools: a questionnaire and a dietary diary. The use of two instruments allowed for more detailed analysis to reveal discrepancies in responses between the two instruments, to improve reliability of study results, and to reduce recall bias. Implementation of the questionnaire was relatively easy and provided a broad characterization of consumption patterns in the area. The dietary diary was more time-consuming, resulting in a reduction in participation rates. It provided, however, more detailed information with which to address community concerns about adverse health effects from mercury exposure. Overall, individuals who participated in this study were able to make broad generalizations about the amount of seafood in their diet but were less accurate in estimating specific seafood consumption levels. In addition, the level of concordance between the questionnaire and the dietary diary was low with respect to seafood consumption levels. For investigators examining consumption patterns in a community, the decision to use a questionnaire, a dietary diary, or both will be influenced by the objectives of the study, the level of community concern, the number of study staff, and available resources.

Neurobehavioral evaluation for a community with chronic exposure to hydrogen sulfide gas.

In May 2000, the Agency for Toxic Substances and Disease Registry of the US government conducted a health investigation in response to community concerns regarding ambient and indoor hydrogen sulfide (H(2)S), odor, and health symptoms in Dakota City, Nebraska. The objective was to determine whether adult residents in an area with repeated exposure to H(2)S showed poorer performance on neurobehavioral tests than unexposed residents. Study participants were required to meet age (#10878;16 years of age) and length of residency (2 years) eligibility requirements. A battery of computer-assisted standardized neurobehavioral tests was administered in English or Spanish. A questionnaire was used to collect information about participants, demographic and health status. Three hundred forty-five people agreed to participate. After the exclusion of 10 persons, analyses were conducted on 335 participants; 171 residents in the target area and 164 residents in the comparison area. The two groups were comparable in demographic characteristics and various health conditions. Overall, neurobehavioral test results for the target and comparison groups were similar. Residence in the H(2)S-exposed area was associated with marginally poorer performance on a test of memory, namely, match to sample score, and a test of grip strength. However, these differences were not significant. Deficits in overall neurobehavioral performance were not associated with exposure to H(2)S in this study.