Sentences with phrase «air pollution levels decreased»

The Fraser Institute found that air pollution levels decreased slightly as a result of shutting down the coal plants in Toronto, Hamilton and Ottawa, but not enough to warrant the expense.

Not exact matches

Since the pollution concentration decreases from west to east, as the distance from Los Angeles increases, the forests offered a rare opportunity to compare emissions from wildland fuels subjected to different levels of chronic air pollution.

The scientists expect further warming in the Arctic as levels of greenhouse gases will continue to increase and aerosol particle emissions will likely decrease to combat air pollution in different parts of the world.

The scientific consensus is that pollution controls enacted through the Clean Air Act Amendments in the 1990s and other measures have helped decrease the acidity of rain by approximately 60 percent to less harmful levels, as reflected in data gathered nationwide and by UD researchers in Lewes, Del., as part of a longstanding study.

Since a large body of evidence links pollution with poor health, and health is an important part of human capital, efforts to reduce pollution could plausibly be viewed as an investment in human capital and thus a tool for promoting economic growth... We find robust evidence that ozone levels well below federal air quality standards have a significant impact on productivity: a 10 ppb decrease in ozone concentrations increases worker productivity by 4.2 percent.