The hundreds of thousands – sometimes millions – of air pollution particles per cubic foot typical in some cities will soon contain fewer toxins such as mercury, arsenic, acid gas and even cyanide. That is the result of new national standards for mercury and other emissions from power plants. The new standards were announced this week by the U.S. Environmental Protection Agency, and they affect the 40 percent of coal-fired power plants across the nation that have not already deployed modern pollution-control technologies.

The EPA announcement is good news for most people. The EPA predicts the standards will prevent as many as 11,000 premature deaths and 4,700 heart attacks a year. And, says the EPA, the cleaner air will prevent 130,00 cases of childhood asthma per year, and 6,300 cases of acute bronchitis. Again, good news, but it’s worth remembering that asthma currently affects about 9 million children in the United States under the age of 18.

But, meanwhile, don’t put off buying that air purifier you’ve been thinking about. While coal-fired power plants are a major source of certain pollutants such as sulfur dioxide and mercury, the wide variety of other pollutants in the air, including but not limited to volatile organic compounds, particle pollution, etc., will still be in plentiful supply. Those other pollutants don’t come from power plants, but rather from agriculture, manufacturing, highway vehicles and other mobile sources, and many others. In other words, if you live near a freeway or high-traffic roadway, for starters, the new EPA regulations may not make much difference in the unhealthy air you breathe. Opt for the air purifier.