Physico-Chemical and Biological Characteristics of Faecal Sludge in Pit Latrines with Depth

Abstract

There is limited information about the characteristics of faecal sludges in ordinary pit latrines. Knowledge of the physico-chemical and biological characteristics of pit sludge from different layers of the pit apart from providing an indication of the nature of pit contents endeavoured to provide information and decision support for managing pit latrines during their normal lifespan. Therefore, this paper was aimed at investigating the physico-chemical and biological characteristics of pit sludge samples to equip latrine owners with environmental and health implications of this sludge. Legislation that establishes regulations specifically for the treatment and discharge, enduse, or disposal of faecal sludge is therefore essential. Thus, faecal sludges sampled from ten (10) pit latrines were subjected to laboratory analyses with particular reference to selected parameters. From the study, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solids (TS), moisture content, suspended solids (SS) and volatile solids (VS) showed decreasing trend throughout as the pit depth increased. Temperature presented double scenarios, increasing initially and decreasing afterwards with the highest values within 0.4m to 0.6m pit depth in all the pit latrines. Efforts to understand and mitigate the health effects of particulate matter (PM) air pollution have a rich and interesting history. This review focuses on six substantial lines of research that have been pursued since 1997 that have helped elucidate our understanding about the effects of PM on human health. There has been substantial progress in the evaluation of PM health effects at different time-scales of exposure and in the exploration of the shape of the concentration-response function. There has also been emerging evidence of PM-related cardiovascular health effects and growing knowledge regarding interconnected general pathophysiological pathways that link PM exposure with cardiopulmonary morbidity and mortality. Despite important gaps in scientific knowledge and continued reasons for some skepticism, a comprehensive evaluation of the research findings provides persuasive evidence that exposure to fine particulate air pollution has adverse effects on cardiopulmonary health. Although much of this research has been motivated by environmental public health policy, these results have important scientific, medical, and public health implications that are broader than debates over legally mandated air quality standards.