RESUMEN
Residential use of natural gas (NG) for heating and cooking purposes may contribute significantly to CH emissions to the atmosphere. To analyze whether the NG demand in the city of Tandil, Argentina, contributes to the increase in atmospheric CH concentration, we conducted systematic collections of time-integrated air samples for a year in six city sites with different population and built-up density. Some meteorological parameters and NG consumption were registered. Atmospheric CH concentration ranged from 1.12 to 1.95 mg m (1.72 to 2.84 ppm) with significant seasonal and spatial variations. In all the sites, with the exception of a peri-urban site bordering rural areas, the maximum CH concentrations were measured during the coldest months, with a statistically significant correlation between residential and commercial NG consumption with respect to air temperature ( < 0.001, = -0.84 to -0.69) and atmospheric CH concentration ( < 0.05, = 0.58 to 0.94). In Argentina, the most popular home heating system is the balanced-draft heater, which has a thermal efficiency of 39 to 63%. This low efficiency allows us to attribute the highest atmospheric CH concentration found during the coldest months mainly to the leaks of the heating systems and the greater residential use of NG. Repairing the gas leaks by increasing thermal efficiency or replacing heating systems with more efficient ones will bring economic, environmental, and health benefits. This study is important for our country where the dependence on the use of NG from heating systems is significant.