Need good news in this heat? Virginia’s air is cleaner | Weather

Middle to late July is climatologically the hottest time of the year for Virginia, and the standards for what constitutes record heat are being rewritten as the planet continues to warm. Temperatures both days this weekend in Richmond will be around 100 degrees.

Good news can be hard to find, but there is some.

The air in Richmond has quietly become cleaner over the past 20 years.

Stepping back a bit, air pollution from factories and cars was worsening through the mid-20th century. The federal Clean Air Act of 1970 established the Environmental Protection Agency and allowed for the development of federal and state regulations to limit emissions from both industrial sources and automobiles.

But it was an amendment in 2000 that created new standards as evidence came to light about how air pollution affects the body. This enabled the EPA to address the pollutants that are the key elements in producing ground level ozone.

Chemically the same as the ozone 10-20 miles overhead protecting us from the sun’s worst ultraviolet rays, ground level ozone is irritating to our lungs. In the bottom few hundred feet of the atmosphere, it forms when sunlight reacts with the other pollutants — typically the hydrocarbons emitted from cars and factories.

An additional federal provision in 2000 addressed the downwind transport of pollution. Virginia generally has westerly winds, meaning pollution from power plants in Ohio was routinely sent into the state, worsening air quality in areas far away from Virginia’s cities, such as Shenandoah National Park.

For those following the data from day-to-day, the impacts of the new regulations and the innovations that followed became visible within a few years.

Dan Salkovitz is a meteorologist in Richmond, working for the Virginia Department of Environmental Quality since 1983, and he has been examining air pollution data for more than 30 years.

“It’s a true success story.”

Code orange ozone days indicate the air is unhealthy for sensitive groups; codes red and purple are unhealthy days for everyone.

Until 2000, Richmond regularly had 1-2 months’ worth of code orange — or worse — ozone days during the summer, but the annual number began to decrease rapidly a few years after the new regulations took effect.

Richmond has not had a code red day since 2012.

Salkovitz notes that there was no singular reason for the improvement.

“Partly due to the new regulation and partly to save money, fuel efficiency began to increase, and cleaner fuels were used. Computers began to better regulate combustion in power plants and factories. Carpooling and using public transportation also helps.”

Other changes have taken place. Natural gas is rapidly replacing coal as a fuel for power plants. Like coal, natural gas is also a fossil fuel, but it is a relatively cleaner burning fuel than coal. And it has become less expensive than coal.

Other pollutants do impact Virginia. In addition to industrial pollution, fine particulate matter within wildfire smoke follows the winds and occasionally moves into the state. Depending on the size of the fire, that smoke can come in from hundreds, if not a few thousand miles away.

Tiny particles in the smoke, called PM2.5, measure 2.5 microns across, or about 20 times smaller than the width of a human hair. These can get deep into the lungs and bloodstream, causing longer-term health problems. They are not common in Virginia, but they are also responsible for the hazy skies that we still occasionally see in the summer.

In addition to occasional periods with wildfire smoke, there is a specific day every year when PM2.5 surges. In the hours that follow fireworks displays on Independence Day, these levels spike all across the country.

Salkovitz remembers one night driving south on I-95 on the way back from Washington.

“At one point, smoke was so thick, particles were hitting my windshield.”

We sometimes forget how bad environmental conditions were several decades ago and that it took numerous rounds of regulation and innovation to improve them. But results are not always as immediate as we might like.

In 1989, regulations were implemented to address the depletion of the ozone layer at the South Pole. Known as the Montreal Protocol, it stopped the figurative bleeding there, but it will take decades for ozone levels to recover.

Often, it takes a while to see a return on investment. The environmental challenges that come with our warming climate continue to become more obvious. How much collective action gets taken to address planetary warming remains an open question.

Curious about the air quality forecasts? Find the daily Virginia DEQ air quality forecasts here.

Learn more about the science of climate change at NASA’s Global Climate Change page.