The air in New York is getting less sulfur dioxide-y. Photo: Don Emmert/AFP/Getty Images

The air you breathe in New York City may not always smell so great, but a new study from the city’s health department says the quality of that air is improving. According to the New York City Air Quality Survey, there have been significant decreases in harmful chemicals in the city’s air in recent years. But the survey, which began in 2008 and collects data samples from sites across the city, also said that some neighborhoods in the South Bronx and Manhattan still emit dangerous levels of pollutants.

From 2008 through 2014 (the most recent year included in the survey), sulfur dioxide levels in the air dropped 68 percent — a change the survey credits to new heating-oil regulations. The report also notes a drop in other pollutants it says can be harmful, especially to seniors, children, and those with preexisting health conditions: nitric oxide levels are down 24 percent, nitrogen dioxide levels are down 21 percent, and there’s been a 16 percent drop in levels of fine particulate matter. According to the report, summertime ozone levels have remained relatively stable over that time period.

The highest concentrations of harmful materials were found in the South Bronx and Manhattan. The report says that higher levels of certain pollutants continue to be observed in areas with higher traffic density and building density, areas with residual oil boilers, and industrial areas.