Aichi Prefecture, which has a dense industrial area, is one of the sites in Japan where the levels of zinc are elevated. However, currently, there is no clear evidence of the source of zinc in this prefecture. This study aims to assess zinc concentration and load in a river and identify the main sources of zinc pollution. We conducted a 20‐month survey to identify the temporal and spatial variation of zinc in river water, particularly in the Aizumame River. Using Flame Atomic Absorption Spectrometry, the total fraction of zinc concentrations was determined for nine sampling stations (five points in the mainstream and four points in the tributaries). The results show that the average of zinc concentration was lower during the irrigation period than in the non‐irrigation period. However, the load during the irrigation period was higher. During irrigation, the river discharges were higher resulting in a lower concentration. The highest zinc concentration was 0.139 mg/L in June 2017. Based on this study, the main zinc source was identified from industrial areas which on average contributed about 3,400 g/day into the mainstream. These results became more evident during the non‐irrigation period when only industrial discharges contributed zinc load into the mainstream.

中文翻译：

---

河流水中锌污染的研究：基于灌溉计划的平均质量平衡

工业区密集的爱知县是日本锌含量高的地区之一。但是，目前尚无该县锌源的明确证据。这项研究旨在评估河流中的锌浓度和负荷，并确定锌污染的主要来源。我们进行了为期20个月的调查，以查明河水中锌的时空变化，特别是在会津玛美河中。使用火焰原子吸收光谱法，测定了九个采样站（主流中的五个点和支流中的四个点）的锌浓度总含量。结果表明，灌溉期间锌的平均浓度低于非灌溉时期。但是，灌溉期间的负荷较高。在灌溉期间，河水流量较高，导致浓度较低。2017年6月，最高锌浓度为0.139 mg / L。根据这项研究，主要工业来源的锌主要来源被确定，平均每天向主流地区贡献约3,400克。在非灌溉时期，只有工业废水将锌负荷带入主流，这些结果变得更加明显。