STUDY - Downstream natural gas composition across U.S. and Canada: Implications

and Canada: Implications for indoor methane leaks and hazardous air pollutant exposures Background The natural gas used in millions of homes across North America is made up of methane, a powerful climate pollutant, and trace amounts of a range of hazardous air pollutants, including the known human carcinogen benzene. [...] Because natural gas is odorless and used in people’s homes, federal regulation in the United States requires that it contain enough odorant to be detectable by KEY TERMS people with a “normal sense of smell.” However, research has shown that gas Benzene leaks from stoves, water heaters, and other residential appliances are common, despite the presence of odorants. [...] This study, published in Environmental Benzene is a volatile organic Research Letters, is the first to assess whether odorant concentrations are compound that is classified as a protective against elevated levels of benzene exposure, and provides the most known human carcinogen by the comprehensive data to date on natural gas composition. [...] variations in the chemical makeup Researchers found that the composition and concentration of gas odorants, as and concentration of both well as the hazardous air pollutants present in natural gas, varied significantly hazardous air pollutants and depending on the location. [...] Given benzene’s toxicity, the ABOUT wide-ranging ability for the general public to smell gas odorants, the prevalence of indoor gas leaks, and methane’s role as a climate pollutant, this study raises PSE HEALTHY concerns that reliance on the average sense of smell may allow some leaks to go undetected, potentially for long periods of time.