Volatile Organic Compounds of the Tap Water in the Watarase, Tone and Edo River System

Ohmichi, Kimihide; Ohmichi, Masayoshi; Machida, Kazuhiko

doi:10.1265/jjh.59.45

Cited by 4 publications

(4 citation statements)

References 2 publications

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“…The main water source for these prefectures relies on the Tone River system (Tone River and Edo River). The Tone River basin features a high population, and rivers flow into human activity areas 27 , 28 . Moreover, these prefectures are located downstream of the Tone River and exhibit a long residence time before being taken in as raw water.…”

Section: Resultsmentioning

confidence: 99%

Distribution of inorganic compositions of Japanese tap water: a nationwide survey in 2019–2024

Hori,

Shozugawa,

Takizawa

et al. 2024

Sci Rep

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A nationwide survey of inorganic components of tap water all over Japan was conducted from 2019 to 2024. In this survey, 1564 tap water samples were collected, and an additional 194 tap water samples were collected from 33 other countries. The water samples were analyzed for 27 dissolved inorganic components, with a primary focus on the distribution of major and trace components, including Ca, Mg, K, Na, Cl−, NO3−, SO42−, total-hardness, Al, Fe, Cu, Mn, and Zn. The Japanese tap water hardness was 50.5 ± 30.2 (± 1σ SD) mg/L, classified as soft water according to the World Health Organization (WHO) classification. The average content of each major component in Japanese tap water tended to be lower than those in other countries. Furthermore, Piper trilinear diagrams were used to categorize Japanese tap water types. The dominating water types were the Ca–HCO3 and mixed types, which had a nationwide distribution. Japanese tap water generally complied with Japanese and WHO drinking water criteria, with only 1% (17/1564 sites) of the samples exceeding water quality standards. Observations of water quality changes for 2 years at three household faucets revealed that fluctuations in major components and trace metals (Al, Fe, Cu, Mn, and Zn) varied in different patterns. This suggests that the behavior of trace metal elements is influenced by local infrastructure, such as supply pipes, distinct from the variability in source water quality.

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Section: Resultsmentioning

confidence: 99%

Distribution of inorganic compositions of Japanese tap water: a nationwide survey in 2019–2024

Hori,

Shozugawa,

Takizawa

et al. 2024

Sci Rep

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“…This river flows through an area where human activities thrive and, accordingly, is an important water source for human activities in the Kanto region. As such, this area includes many sources of water pollution from human activities 38 . Moreover, these three prefectures (Chiba, Saitama, and Tokyo) are located downstream of the Tone River; the linear distance from the headwater to sluice gates is more than 150 km and exhibits a long residence time before being taken in as raw water.…”

Section: Resultsmentioning

confidence: 99%

A survey of monitoring tap water hardness in Japan and its distribution patterns

Hori

Shozugawa

Sugimori

et al. 2021

Sci Rep

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We conducted a comprehensive overall tap water hardness assessment for Japan. Tap water was collected from 665 points throughout Japan, and its standing position was quantitatively clarified by prefecture. The mean and median hardness of tap water in Japan was 48.9 ± 25.8 (1σ SD) and 46.0 mg/L, respectively. Compared with 27 other countries, Japan exhibited soft water with low-mineral content. Water hardness tended to be high in the Kanto region and low in the Hokkaido and Tohoku regions. The impact of the distribution system’s water pipes on tap water hardness is discussed using a unified index to evaluate variations in hardness from raw to tap water. A comparison of the variations in hardness showed that hardness variations from raw to purified water and from purified to tap water exhibited a 20% variation range. Furthermore, tap water hardness and its fluctuations in any region of Japan were found to be caused by raw water hardness. It was demonstrated that the distribution pipe system had no large impacts on water hardness.

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“…In our previous investigations [4][5][6][7] for the rivers around the Ashio Mine, a slight degree of pollution by heavy metals had already been confirmed. In this study, we conducted a follow-up investigation to confirm the degree of improvement of environmental circumstances around the basin of the Watarase River *To whom correspondence should be addressed: Japan Food Hygiene Association, 2-6-1 Jingumae, Shibuyaku, Tokyo 150-0001, Japan.…”

Section: Introductionmentioning

confidence: 96%

Recent Heavy Metal Concentrations in Watarase Basin around Ashio Mine

Ohmichi¹,

Seno

Takahashi

et al. 2006

JOURNAL OF HEALTH SCIENCE

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Pollution in the Watarase River caused by mineral wastewater containing high levels of copper discharged during the development of the Ashio CopperMine is one of the most well-known environmental pollution problems in Japan, and has been called the "Starting line of environmental pollution problems in Japan." In this study, we conducted follow-up investigations on the conditions of pollution in the Watarase River since 1991, and measured the heavy-metal levels in water in other rivers near the Watarase River and in soils around them. In addition, we compared the results in this study with previous results, i.e. pollution conditions in the Watarase River, other rivers and soils. Six points in upstream sites of the Watarase were chosen for sampling. Six samples from river water, five samples from soils around the respective points, and three samples from tap water distributed there were collected for the analysis. Heavy metal levels in rivers and soils around the Ashio Copper Mine were significantly lower than the environmental standards for them. When compared with our previous investigations, the levels of polluting heavy metals around the closed refinery at the Ashio Mine were gradually but clearly reduced. In conclusion, the environment around the Watarase River has been steadily improved so that safety in the living environment is assured.

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Volatile Organic Compounds of the Tap Water in the Watarase, Tone and Edo River System

Cited by 4 publications

References 2 publications

Distribution of inorganic compositions of Japanese tap water: a nationwide survey in 2019–2024

Distribution of inorganic compositions of Japanese tap water: a nationwide survey in 2019–2024

A survey of monitoring tap water hardness in Japan and its distribution patterns

Recent Heavy Metal Concentrations in Watarase Basin around Ashio Mine

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