Division of Environmental Health Sciences, University of California, Berkeley School of Public Health, Berkeley, California, USA.
Division of Epidemiology, University of California, Berkeley School of Public Health, Berkeley, California, USA.
Environ Health Perspect. 2022 Jan;130(1):17002. doi: 10.1289/EHP9468. Epub 2022 Jan 5.
Hundreds of thousands of biodigesters have been constructed in Nepal. These household-level systems use human and animal waste to produce clean-burning biogas used for cooking, which can reduce household air pollution from woodburning cookstoves and prevent respiratory illnesses. The biodigesters, typically operated by female caregivers, require the handling of animal waste, which may increase domestic fecal contamination, exposure to diarrheal pathogens, and the risk of enteric infections, especially among young children.
We estimated the effect of daily reported biogas cookstove use on incident diarrhea among children old in the Kavrepalanchok District of Nepal. Secondarily, we assessed effect measure modification and statistical interaction of individual- and household-level covariates (child sex, child age, birth order, exclusive breastfeeding, proof of vaccination, roof type, sanitation, drinking water treatment, food insecurity) as well as recent 14-d acute lower respiratory infection (ALRI) and season.
We analyzed 300,133 person-days for 539 children in an observational prospective cohort study to estimate the average effect of biogas stove use on incident diarrhea using cross-validated targeted maximum likelihood estimation (CV-TMLE).
Households reported using biogas cookstoves in the past 3 d for 23% of observed person-days. The adjusted relative risk of diarrhea for children exposed to biogas cookstove use was 1.31 (95% confidence interval (CI): 1.00, 1.71) compared to unexposed children. The estimated effect of biogas stove use on diarrhea was stronger among breastfed children (2.09; 95% CI: 1.35, 3.25) than for nonbreastfed children and stronger during the dry season (2.03; 95% CI: 1.17, 3.53) than in the wet season. Among children exposed to biogas cookstove use, those with a recent ALRI had the highest mean risk of diarrhea, estimated at 4.53 events (95% CI: 1.03, 8.04) per 1,000 person-days.
This analysis provides new evidence that child diarrhea may be an unintended health risk of biogas cookstove use. Additional studies are needed to identify exposure pathways of fecal pathogen contamination associated with biodigesters to improve the safety of these widely distributed public health interventions. https://doi.org/10.1289/EHP9468.
尼泊尔已经建造了数十万个生物消化池。这些家庭层面的系统利用人类和动物的废物来产生清洁燃烧的沼气，用于烹饪，从而减少了家庭因燃烧木柴炉灶而造成的空气污染，并预防了呼吸道疾病。这些生物消化池通常由女性照顾者操作，需要处理动物废物，这可能会增加家庭粪便污染，接触腹泻病原体，并增加肠道感染的风险，尤其是在幼儿中。
我们估计了在尼泊尔卡瓦普区，每天报告的沼气炉使用对 0-5 岁儿童发生腹泻的影响。其次，我们评估了个体和家庭层面的协变量（儿童性别、儿童年龄、出生顺序、纯母乳喂养、疫苗接种证明、屋顶类型、卫生设施、饮用水处理、粮食不安全）以及最近 14 天急性下呼吸道感染（ALRI）和季节的效量修正和统计交互作用。
我们对一个观察性前瞻性队列研究中的 539 名儿童的 300,133 人日进行了分析，使用交叉验证靶向最大似然估计（CV-TMLE）来估计沼气炉使用对腹泻发生率的平均影响。
家庭报告过去 3 天中每天有 23%的观察人日使用沼气炉。与未暴露的儿童相比，暴露于沼气炉使用的儿童腹泻的相对风险为 1.31（95%置信区间（CI）：1.00，1.71）。与非母乳喂养儿童相比，沼气炉使用对母乳喂养儿童腹泻的影响更强（2.09；95%CI：1.35，3.25），与雨季相比，沼气炉使用对腹泻的影响在旱季更强（2.03；95%CI：1.17，3.53）。在暴露于沼气炉使用的儿童中，最近患有 ALRI 的儿童腹泻的平均风险最高，估计为每 1,000 人日 4.53 例（95%CI：1.03，8.04）。
这项分析提供了新的证据，表明儿童腹泻可能是沼气炉使用的一个意想不到的健康风险。需要进一步的研究来确定与生物消化池相关的粪便病原体污染的暴露途径，以提高这些广泛分布的公共卫生干预措施的安全性。
