Gwenzi Willis, Marumure Jerikias, Makuvara Zakio, Simbanegavi Tinoziva T, Njomou-Ngounou Emma Laureane, Nya Esther Laurentine, Kaetzl Korbinian, Noubactep Chicgoua, Rzymski Piotr
Grassland Science and Renewable Plant Resources, Faculty of Organic Agricultural Sciences, Universität Kassel, Steinstraße 19, D-37213 Witzenhausen, Germany; Leibniz-Institut für Agrartechnik und Bioökonomie e.V. (ATB), Max-Eyth-Allee 100, 14469 Potsdam, Germany.
Department of Physics, Geography and Environmental Sciences, School of Natural Sciences, Great Zimbabwe University, Off Old Great Zimbabwe Road, P.O. Box 1235, Masvingo, Zimbabwe; Department of Life and Consumer Sciences, School of Agriculture and Life Sciences, College of Agriculture and Environmental Sciences, University of South Africa, South Africa.
Sci Total Environ. 2023 Jun 25;879:163179. doi: 10.1016/j.scitotenv.2023.163179. Epub 2023 Mar 31.
Pit latrines are widely promoted to improve sanitation in low-income settings, but their pollution and health risks receive cursory attention. The present narrative review presents the pit latrine paradox; (1) the pit latrine is considered a sanitation technology of choice to safeguard human health, and (2) conversely, pit latrines are pollution and health risk hotspots. Evidence shows that the pit latrine is a 'catch-all' receptacle for household disposal of hazardous waste, including; (1) medical wastes (COVID-19 PPE, pharmaceuticals, placenta, used condoms), (2) pesticides and pesticide containers, (3) menstrual hygiene wastes (e.g., sanitary pads), and (4) electronic wastes (batteries). Pit latrines serve as hotspot reservoirs that receive, harbour, and then transmit the following into the environment; (1) conventional contaminants (nitrates, phosphates, pesticides), (2) emerging contaminants (pharmaceuticals and personal care products, antibiotic resistance), and (3) indicator organisms, and human bacterial and viral pathogens, and disease vectors (rodents, houseflies, bats). As greenhouse gas emission hotspots, pit latrines contribute 3.3 to 9.4 Tg/year of methane, but this could be an under-estimation. Contaminants in pit latrines may migrate into surface water, and groundwater systems serving as drinking water sources and pose human health risks. In turn, this culminates into the pit latrine-groundwater-human continuum or connectivity, mediated via water and contaminant migration. Human health risks of pit latrines, a critique of current evidence, and current and emerging mitigation measures are presented, including isolation distance, hydraulic liners/ barriers, ecological sanitation, and the concept of a circular bioeconomy. Finally, future research directions on the epidemiology and fate of contaminants in pit latrines are presented. The pit latrine paradox is not meant to downplay pit latrines' role or promote open defaecation. Rather, it seeks to stimulate discussion and research to refine the technology to enhance its functionality while mitigating pollution and health risks.
坑式厕所被广泛推广用于改善低收入地区的卫生状况，但其污染问题和健康风险却受到了草率的关注。本叙述性综述提出了坑式厕所悖论：（1）坑式厕所被视为保障人类健康的首选卫生技术；（2）相反，坑式厕所却是污染和健康风险的热点地区。有证据表明，坑式厕所是家庭处置危险废物的“万能”容器，包括：（1）医疗废物（新冠疫情个人防护装备、药品、胎盘、用过的避孕套）；（2）农药及农药容器；（3）经期卫生用品（如卫生巾）；（4）电子废物（电池）。坑式厕所成为了热点储存库，接收、容纳并随后将以下物质传播到环境中：（1）常规污染物（硝酸盐、磷酸盐、农药）；（2）新兴污染物（药品和个人护理产品、抗生素耐药性）；（3）指示生物、人类细菌和病毒病原体以及病媒（啮齿动物、家蝇、蝙蝠）。作为温室气体排放热点，坑式厕所每年排放3.3至9.
