鑄造製程勞工PAHs暴露評估

鑄造是工業之母，鑄造是將熔融狀金屬倒入模具，讓金屬冷卻凝固，形成特定形狀的製程，為各類金屬製品的前段製程，廣泛運用在各種製造業中，如工具機製造業，汽車製造業、航空製造業等。鑄造的模具材料會依照所需要的成品而有所不同，如砂模鑄造和陶芯鑄造。一般鑄造大多使用回收廢鐵雜質多，不管是哪種鑄造方法皆會因為高溫金屬鐵水造成有機物不完全燃燒進而產生多環芳香烴暴露。多環芳香烴是一百多種不同化學物質的合稱，當煤炭、燃油、瓦斯、垃圾或其他有機物質(如：菸草或肉)燃燒不完全時就會形成，一些多環芳香烴化合物，特別是含有四個環或更多環的多環芳香烴，已知具有致癌性和致突變性，已被列入歐盟優先污染物清單。本研究共選擇了3間進行鑄造製程的工廠，藉由區域及個人採樣方式探討勞工於作業場所暴露多環芳香烴之情況，樣本是參考 NIOSH 5506 分析方法，以高效液相層析(HPLC)分析各項物質濃度，並進行健康風險評估。以及對受測的勞工進行尿液生物偵測，分析尿中多環芳香烴代謝物濃度與尿中心血管疾病指標及免疫功能指標，再將生物偵測結果與空氣採樣結果使用PC-SPSS 20.0 進行相關性分析。本次研究中，三間工廠的多環芳香烴濃度皆無超過容許暴露濃度，不過在40個個人空氣樣本中。有24個樣本的非致癌風險超過危害指標1，表示暴露劑量超過閾值可能產生毒性；而絕大部分的樣本，致癌風險超過職場中可接受致癌風險為10-3~10-4，這可能對工人的健康造成嚴重影響，因此建議要採取相關防護措施。在本次研究中，計算了各廠PAHs的平均當量濃度Bapeq，A廠的平均當量濃度為3180.8ng/m3、B廠的平均當量濃度為4867.6 ng/m3、C廠的平均當量濃度為5319.7204 ng/m3發現在A、B、C三廠中皆是以Dibenzo[ah] Anthracen在Bapeq占比最高尿液中1-OHP與空氣中Pyrene的相關性，發現並無顯著相關，推測是因為在進行鑄造時勞工們都會配戴呼吸防護具，進而減少了Pyrene的暴露吸入，或是勞工暴露吸入Pyrene，但是採集尿液時Pyrene尚未完全轉化成1-OHP。在本次研究中，發現1-OHP的濃度與TNF-α的濃度呈顯著正相關(r=0.605，p<0.00)，1-OHP的濃度與TLP的濃度呈顯著正相關(r=0.800，p<0.00)。在本次研究中，我國職場容許暴露標準僅有萘有容許暴露值，其他為致癌物或是疑似致癌物的PAHs並無訂定標準。因此建議應增加相關容許暴露濃度標準，並參考國外相關資料訂定危害物質之暴露限值，確保暴露評估之準確性，減少未來職業病的產生。本次研究為橫斷研究，研究結果為單次採樣結果，若想確認關係，建議需要進行多次採樣，追蹤同一批測試者，以確認暴露情況。

Casting is the mother of industry. Casting involves pouring molten metal into molds, allowing the metal to cool and solidify, forming specific shapes. This process is a preliminary stage for various metal products and is widely used in various manufacturing industries such as machine tool manufacturing, automotive manufacturing, and aerospace manufacturing. The materials used for casting molds vary according to the required finished product, such as sand casting and ceramic core casting. Generally, casting mostly uses recycled scrap iron, which contains many impurities. Regardless of the casting method, the high-temperature molten metal causes incomplete combustion of organic matter, resulting in polycyclic aromatic hydrocarbons (PAH) exposure. PAHs are a collective term for more than 100 different chemical substances formed when coal, fuel oil, gas, garbage, or other organic substances (such as tobacco or meat) are burned incompletely. Some PAH compounds, especially those with four or more rings, are known to be carcinogenic and mutagenic and have been listed on the EU priority pollutants list.This study selected three foundries to explore the exposure of workers to PAHs in the workplace through area and personal sampling methods. The samples were analyzed using the NIOSH 5506 method, with High-Performance Liquid Chromatography (HPLC) to determine the concentration of various substances and conduct a health risk assessment. Urine biomonitoring of the tested workers was also performed to analyze the concentration of PAH metabolites in urine and indicators of cardiovascular disease and immune function. The biomonitoring results and air sampling results were analyzed for correlation using PC-SPSS 20.0.In this study, the concentration of PAHs in the three foundries did not exceed the permissible exposure limits. However, in 24 out of 40 personal air samples, the non-carcinogenic risk exceeded the hazard index of 1, indicating that exposure levels might be toxic. The carcinogenic risk for most samples exceeded the acceptable workplace carcinogenic risk of 10-3 to 10-4, which could seriously affect workers' health. Therefore, related protective measures should be implemented. The average equivalent concentration of PAHs (Bapeq) was calculated for each foundry: Foundry A had an average equivalent concentration of 3180.8 ng/m3, Foundry B had 4867.6 ng/m3, and Foundry C had 5319.7204 ng/m3. It was found that Dibenzo[ah]Anthracene had the highest Bapeq ratio in all three foundries.The correlation between 1-OHP in urine and Pyrene in the air was not significant, possibly because workers wore respiratory protective equipment during casting, reducing Pyrene inhalation, or Pyrene was not completely metabolized into 1-OHP when urine was collected. In this study, a significant positive correlation was found between 1-OHP concentration and TNF-α concentration (r=0.605, p<0.00), and between 1-OHP concentration and TLP concentration (r=0.800, p<0.00).In this study, the permissible exposure standard for workplaces in our country only includes Naphthalene. Other carcinogenic or suspected carcinogenic PAHs do not have set standards. Therefore, it is recommended to increase related permissible exposure concentration standards and refer to foreign data to set exposure limits for hazardous substances to ensure accurate exposure assessment and reduce the occurrence of occupational diseases in the future. This study is a cross-sectional study, and the results are from single sampling. To confirm the relationships, it is suggested to conduct multiple samplings and follow the same group of testers to confirm exposure conditions