Graduate School of Global Environmental Studies, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
Life Science School, Khulna University, Gallamari, Khulna 9208, Bangladesh.
J Water Health. 2021 Dec;19(6):946-958. doi: 10.2166/wh.2021.111.
Seasonal and gender impacts have not been well considered in fecal exposure assessment, especially in low- and middle-income countries. This study examined the seasonal and gender impacts on fecal exposure trends in children through daily living activities in an urban slum in Bangladesh. We determined Escherichia coli concentrations in seven types of environmental samples (n = 232) and the activity data of children via diary recording, questionnaires, and interview surveys. Daily and monthly exposures were stochastically estimated for drinking, eating, pond bathing, well bathing, and hand-to-mouth contact. Of the five pathways, pond bathing and drinking contributed a large part of the daily and monthly exposure. Significant seasonal differences were observed in daily exposures for bathing, which were higher in the rainy season (2.59 × 10 CFU/day for boys and 6.19 × 10 CFU/day for girls) than in the dry season (1.69 × 10; 4.30 × 10), because of longer pond bathing time and more contaminated bathing water in the rainy season. In contrast, eating had significantly higher exposure in the dry season (3.71 × 10; 3.22 × 10) than the rainy season (1.50 × 10; 1.24 × 10) due to the higher dish contamination. Significantly higher daily exposure was observed in the bathing for boys than girls, as boys spent longer time for bathing at a heavily contaminated pond.
在粪便暴露评估中，季节性和性别影响因素尚未得到充分考虑，尤其是在中低收入国家。本研究通过在孟加拉国一个城市贫民窟中对儿童的日常活动进行调查，研究了季节性和性别对粪便暴露趋势的影响。我们通过日记记录、问卷调查和访谈调查，确定了七种环境样本（n = 232）中大肠杆菌的浓度和儿童的活动数据。通过随机估计，我们确定了儿童通过饮水、饮食、池塘洗浴、井水洗浴和手口接触五种途径的日暴露量和月暴露量。在五种暴露途径中，池塘洗浴和饮水是日暴露量和月暴露量的主要来源。洗浴的日暴露量存在明显的季节性差异，雨季的日暴露量（男孩为 2.59×10 CFU/天，女孩为 6.19×10 CFU/天）高于旱季（男孩为 1.69×10；女孩为 4.30×10），这是由于雨季池塘洗浴时间更长，洗浴水更脏。相比之下，由于雨季餐盘污染程度较低，饮食的日暴露量在旱季（男孩为 3.71×10；女孩为 3.22×10）明显高于雨季（男孩为 1.50×10；女孩为 1.24×10）。由于男孩在污染严重的池塘中洗浴时间更长，因此男孩的日暴露量明显高于女孩。
