Reducing Shipping Air Pollution Bodes Well

California fuel regulations aimed at reducing air pollution from commercial shipping may lead to greater health benefits than expected, according to a study led by NOAA researchers. To reduce emissions of pollutants such as sulfur dioxide and particulate matter, which contribute to respiratory illnesses, California limits the sulfur content of marine gas oil to 1.5% when ships are within 44.5 km (about 28 miles) of the state’s coast. Daniel A. Lack of NOAA’s Earth System Research Laboratory, in Boulder, Colo., and coworkers decided to monitor a container vessel that made the switch from fuel with 3.15% sulfur to one with 0.07% sulfur as it neared the Port of Los Angeles. They found via mass spectrometry and other techniques that levels of sulfur dioxide, sulfate, and particulate matter dropped by at least 88% when the ship slowed and entered the regulated waters (Environ. Sci. Technol., DOI: 10.1021/es2013424). In addition, Lack’s team observed a 75% decrease in black carbon after the fuel switch, a pollutant that they hadn’t expected to change significantly. “We were able to show that these regulations may have an even better effect on human health than intended,” Lack says.