A new study recently published in the Proceedings of the National Academy of Sciences of the USA (PNAS) indicates that after fifty years of fruitful efforts aimed at the improvement of air quality, pollution may be regaining positions.
The research based a combination of data from satellites, computer simulations and ground-based air quality monitoring stations to reach their conclusions found that after all it may be harder than previously thought to get the air cleaner.
Apparently, carbon monoxide and nitrogen oxide that, in combination with automotive exhaust, and electricity plants and industrial smokestacks are the main contributors to the formation of ozone, especially in warm temperatures.
One of the reasons is that the level of emissions from heavy-duty diesel trucks still remains to too high.
While from 2005 to 2009 pollution levels from nitrogen oxide dropped 7% they only inched down 1.7% in the first half of the current decade.
“We were surprised by the discrepancy between the estimates of emissions and the actual measurements of pollutants in the atmosphere,” said Zhe Jiang, lead author of the study.
In addition, while some researches believed that pollution could be coming across the Pacific from Asia, the study showed to the opposite: pollution slowdown was most noteworthy across the eastern states.