Natural gas odorants: A scoping review of health efects

摘要

Purpose of Review Organosulfur compounds are intentionally added to natural gas as malodorants with the intent of short-term nasal inhalation to aid in leak detection. Regulatory exposure limits have not been established for all commonly used natural gas odorants, and recent community-level exposure events and growing evidence of indoor natural gas leakage have raised concerns associated with natural gas odorant exposures. We conducted a scoping review of peer-reviewed scientifc publications on human exposures and animal toxicological studies of natural gas odorants to assess toxicological profles, exposure potential, health efects and regulatory guidelines associated with commonly used natural gas odorants. Recent Findings We identifed only 22 studies which met inclusion criteria for full review. Overall, there is limited evidence of both transient nonspecifc health symptoms and clinically diagnosed causative neurotoxic efects associated with prolonged odorant exposures. Across seven community-level exposure events and two occupational case reports, consistent symptom patterns included: headache, ocular irritation, nose and throat irritation, respiratory complaints such as shortness of breath and asthma attacks, and skin irritation and rash. Of these, respiratory infammation and asthma exacerbations are the most debilitating, whereas the high prevalence of ocular and dermatologic symptoms suggest a non-inhalation route of exposure. Summary The limited evidence available raises the possibility that organosulfur odorants may pose health risks at exposures much lower than presently understood, though additional dose-response studies are needed to disentangle specifc toxicologic efects from nonspecifc responses to noxious organosulfur odors. Numerous recommendations are provided including more transparent and prescriptive natural gas odorant use practices.