Gift J S, Faust R A
National Center for Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
J Expo Anal Environ Epidemiol. 1997 Jul-Sep;7(3):345-58.
Silicosis from inhalation of silica has long been recognized as an occupational hazard. Concern has arisen regarding the potential risk of silicosis from ambient silica (primarily quartz dust). This presentation reviews available data regarding ambient silica levels and estimates of the risk of silicosis at low exposure levels as they relate to the current U.S. Environmental Protection Agency National Ambient Air Quality Standards (NAAQS) for particulate matter. Current data indicate that for individuals not compromised by other respiratory ailments and for ambient environments expected to sustain 10% or less silica fraction in particulate matter with a mean aerodynamic diameter of < or = 10 microns (PM10), maintenance of the 50 micrograms/m3 annual NAAQS for PM10 is adequate to protect against fibrotic effects from ambient silica exposures. Issues such as the large divergence of risk estimates within the occupational setting (particularly at high cumulative exposures) and factors to consider for extrapolating risk in an occupational setting to risk from ambient exposure are discussed.
长期以来，吸入二氧化硅导致的矽肺病一直被视为一种职业危害。人们对环境中的二氧化硅（主要是石英粉尘）引发矽肺病的潜在风险产生了担忧。本报告回顾了有关环境二氧化硅水平的现有数据，以及低暴露水平下矽肺病风险的估计，这些数据与美国环境保护局现行的颗粒物国家环境空气质量标准（NAAQS）相关。当前数据表明，对于未受其他呼吸道疾病影响的个体，以及预计颗粒物中二氧化硅含量维持在10%或更低、平均空气动力学直径小于或等于10微米（PM10）的环境，维持PM10每年50微克/立方米的NAAQS足以防止环境二氧化硅暴露造成的纤维化影响。文中讨论了职业环境中风险估计的巨大差异（尤其是在高累积暴露情况下），以及将职业环境中的风险外推至环境暴露风险时需要考虑的因素等问题。
