WASHINGTON (CN) - Controls on nitrogen dioxide will be tightened for the first time in 35 years to better tackle the respiratory threat of brief but high-level exposure to the pollutant, the Environmental Protection Agency announced Monday.
"For the first time ever, we are working to prevent short-term exposures in high-risk NO2 zones like urban communities and areas near roadways," EPA Administrator Lisa Jackson said in a released statement.
The announcement is part of a broader government effort to reduce pollutants - including carbon dioxide. In May, Obama set in motion restrictions to raise vehicle efficiency from the current average of 25 miles per gallon to an average of 35.5 miles per gallon by 2016.
When asked why the agency decided now to implement tighter NO2 regulations, an EPA spokeswoman, who declined to be named, said that new data shows the dangers of short-term high exposure to NO2, although she said it is difficult to determine how many victims fall ill as a direct result exposure.
Instead of taking annual averages of NO2 levels, monitors will now take hourly measurements to catch spikes in concentration. Hourly levels will not be allowed to go above 100 parts per billion.
Such spikes have been linked to increases in lung infections and other respiratory problems and high concentrations are usually found near major roads. Cars and power plants are some of the largest emitters of NO2.
A Health Effects Institute report released earlier this month shows that 30 to 45 percent of city-dwelling Americans live in areas that are heavily affected by such pollution.
To implement the new limits, NO2 monitors will be placed in cities with populations of more than 500,000 by 2013, and data will then be collected for three years. States will then have to address any violations.
The spokesperson said that NO2 levels are already expected to drop, pointing to limits for on-road diesel vehicles that were phased in since 2007, with the measure finalizing this year. There are also plans to tighten restrictions on off-road diesel vehicle emissions, like construction equipment.
The older annual standard required no more than 53 parts per billion of NO2. But the EPA representative said the annual standard cannot be compared to the 100 parts per billion hourly standard because of the different time element.
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