土壤污染整治人員重金屬暴露之健康風險評估

Abstract

臺灣環境部列管土壤污染場址，又以重金屬污染場址占比最高，而為整治土壤污染，需整治人員至土壤污染場址進行整治，惟執行整治工作時，其可能經由攝入（誤食土壤）、吸入、皮膚接觸等暴露途徑接觸到重金屬，導致健康風險增加，影響身體健康，因此進行健康風險評估至關重要，並了解不同暴露途徑對於重金屬暴露的貢獻百分比，進而提供降低整治人員重金屬暴露的建議。 本研究選定新北市一處觀光區附近及屏東縣另一處非觀光區進行健康風險評估，使用加速規收集整治人員於執行整治工作時的呼吸速率，並以受體附載量分析及問卷調查整治人員各暴露途徑暴露頻率、暴露時間等參數，使用微波輔助王水消化法 ( NIEA S301.61B)，以測定土壤中重金屬含量，透過Crystal Ball軟體進行蒙地卡羅分析，評估污染場址之居民、整治人員集居民非致癌風險及致癌風險。 本研究測得整治人員於工作時呼吸速率中位數為14.5 m3/day （幾何平均值為15.6 m3/day；標準差為1.4 m3/day），而非整治人員之呼吸速率則是中位數為12.9 m3/day（幾何平均值為13.2 m3/day；標準差為1.3 m3/day），顯示出整治人員因高強度工作呼吸速率較高。健康風險評估部分，使用蒙地卡羅分析結果顯示，新北及屏東污染場址整治人員之非致癌風險皆較居民高，遊客則是最低，而致癌風險則是皆居民較整治人員高，因其暴露年數最長，遊客則是最低，而皮膚接觸為其主要影響暴露途徑，攝入則次之，建議兩地人員皆應減少碰觸污染土壤，及手口行為（手觸碰口鼻眼），而在新北場址主要以砷造成非致癌及致癌風險高，屏東場址則為鉻造成非致癌及致癌風險高，建議新北場址應盡快降低砷污染，屏東場址則是應降低鉻污染，本研究結果可提供政府與相關單位在未來對污染場址管理與執行決策時參考，並降低作業環境中重金屬暴露風險之建議。

The Taiwan Environmental Protection Administration regulates contaminated soil sites, with heavy metal contamination accounting for the highest proportion. To remediate soil pollution, remediation personnel must conduct remediation work at contaminated sites. However, during remediation activities, they may be exposed to heavy metals through ingestion (accidental soil ingestion), inhalation, or dermal contact, and other exposure way, increasing health risks and adversely affecting physical well-being. Therefore, conducting a health risk assessment is crucial to understand the percentage contribution of different exposure pathways to heavy metal exposure, thereby providing recommendations to reduce heavy metal exposure among remediation personnel. This study selected a site near a tourist area in New Taipei City and another non-tourist area in Pingtung County for health risk assessment. Accelerometers were used to collect respiratory rate data from remediation personnel during remediation work. Soil adherence analysis and questionnaires were employed to determine parameters such as exposure frequency and duration for each exposure pathway. Microwave Assisted Aqua Regia Digestion (NIEA S301.61B) was used to determine heavy metal concentrations in soil. to determine soil heavy metal concentrations. Monte Carlo analysis via Crystal Ball software assessed non-carcinogenic and carcinogenic risks for residents and remediation workers at contaminated sites. This study measured the median respiratory rate of remediation personnel during work as 14.5 m³/day (geometric mean: 15.6 m³/day; standard deviation: 1.4 m³/day), while the respiratory rate of non-remediation personnel was a median of 12.9 m³/day (geometric mean: 13.2 m³/day; standard deviation 1.3 m³/day), indicating higher respiratory rates among remediation workers due to the high-intensity nature of their work. Under health risk assessment, Monte Carlo analysis results showed that non-carcinogenic risks for remediation workers at both the New Taipei and Pingtung contaminated sites were higher than those for residents, while visitors had the lowest risks. For carcinogenic risks, residents faced higher risks than remediation workers due to their longest exposure duration, while visitors had the lowest risks. Skin contact was the primary exposure route, followed by ingestion. Recommendations include minimizing contact with contaminated soil and hand-to-mouth behaviors (touching eyes, nose, or mouth with hands) for personnel at both sites. At the New Taipei site, arsenic was the primary contributor to elevated non-carcinogenic and carcinogenic risks, while at the Pingtung site, chromium poses elevated non-carcinogenic and carcinogenic risks. Recommendations include promptly reducing arsenic contamination at the New Taipei site and chromium contamination at the Pingtung site. These findings provide reference for government and relevant agencies in future management and decision-making regarding contaminated sites, offering suggestions to mitigate heavy metal exposure risks in operational environments.