That has all changed, in part because of cleaner-burning fuel — its 2006 rollout had been mandated in 2000 by the Clinton administration — that has 97percentt less of the sulfur responsible for diesel engines' sooty particulates.
Although more people are travelling by train, this is not necessarily because of faster, cleaner and more reliable services.
"It may be because of the cleaner water but it is definitely also because of the warming climate," Mr. Schoelkopf said.
The board is looking into how to detect or scare off birds, which experts testified were growing rapidly in number because of a cleaner environment.
Humpback whales are surging in numbers because of the cleaner waters.
Other participants thought that rural communities were healthier because of a cleaner environment, more opportunities for physical activity, increased exposure to the sun resulting in higher vitamin D levels, and the positive impact of greater social unity on mental health.
The fan coil units in the first three rooms (A-C) were considered for the tests, while that located in the virology laboratory (D) was chosen as a control because of its cleaner conditions, due to the lower number of persons who normally work in this room.
With the closing of the Hunters Point and Potrero plants, she said, the city began drawing more electricity from a wide grid of cleaner power, because of a diverse mix of fossil fuel, nuclear and renewable energy sold by PG&E that generates fewer carbon emissions.
But the surge of cheap natural gas may not do much to reduce long-term U.S. emissions of carbon dioxide, a new study suggests, because it could delay the deployment of cleaner renewable energy sources such as solar and wind.
According to the U.S. Environmental Protection Agency, the air inside the typical home is on average 2-5 timoremore polluted than the air just outside--and in extreme cases 100 times more contaminated--largely because of household cleaners and pesticides.
But many studies indicate that overall job numbers are likely to hold steady or to increase because moving to cleaner sources of energy is expected to create new jobs.
