Application of stable isotope of water and a Bayesian isotope mixing model (SIMMR) in groundwater studies: a case study of the Granvillebrook and Kingtom dumpsites.

The increase in groundwater salinity of the two major dumpsites in Sierra Leone has been a major concern for stakeholders. Therefore, this study employed geochemical and stable water isotope analyses to investigate the factors controlling groundwater salinity. The proportional sources of the groundwaters were also evaluated using the Bayesian isotope mixing model. The geochemical analysis showed that the groundwater chemistry in the Granvillebrook dumpsite is controlled by water-rock interaction and evaporation while that of the Kingtom is dominated by water-rock interaction and precipitation. The biplot of deuterium (δ2H) versus oxygen (δ18O) composition relative to the global meteoric water line confirms that the groundwaters of the study areas are of meteoric origin. The linear plot of electrical conductivity versus δ18O depicts that mineralization is the major factor impacting the groundwater salinity in the study areas. The stable isotope mixing model in R (SIMMR) suggests that 96.5% of the groundwaters in the study areas are recharged by precipitation while only 3.5% originated from surface water. The SIMMR model also depicts that groundwaters in the Granvillebrook dumpsite have been bridged by leachate (33.0%) and domestic wastewater (15.2%) while for the Kingtom dumpsite, 13% and 21.5% are contaminated by leachate and domestic wastewaters. Contrary to other previous studies, this research confirms the feasibility of using the Bayesian isotope mixing model to quantify the factors influencing groundwater salinity.

Caregiver perceptions of the food marketing environment of African-American 3-11-year-olds: a qualitative study.

OBJECTIVE: To assess caregivers' perceptions of the extent to which the food marketing environment influences food consumption among African-American children (aged 3­11 years) in order to generate potential strategies to make the marketing environment more favourable to healthier eating. DESIGN: Individual semi-structured interviews with caregivers were conducted by trained community leaders to ascertain their awareness of and perceptions about food marketing environments contributing to African-American children's food consumption. SETTING: Six predominantly African-American communities in metro Birmingham, Alabama, USA with high proportions of school-age children and lower-income residents. SUBJECTS: Caregivers (n 25) were predominantly female (93 %) and either parents/guardians (64 %) or grandparents (28 %) of African-American children aged 3­11 years. Caregiver mean age was 43 years and 46 % had lived in their current residence for over 10 years. RESULTS: Caregivers reported all aspects of the food marketing matrix as supporting unhealthy eating among African-American youth. Child preference for foods higher in fat and sugar, lower pricing of less healthy foods, limited access to healthier food retailers and targeted advertisements were particularly influential on the food selection, acquisition and consumption of children. Company loyalty, corporate sponsorship of local events and conflicts over parental v. food company responsibility contributed to less consensus about the overall impact (positive or negative) of food companies in African-American communities. CONCLUSIONS: While caregivers perceived aspects of their food marketing environments as primarily contributing to unhealthy eating among African-American children, framing the demand for changes in the food marketing environments of African-American youth may be particularly challenging.