In 1988, Ronald Reagan was president, the first George Bush was elected to succeed him and Barack Obama was a first-year student at Harvard University's law school. A lot has changed since then, but the air toxics guidelines that Allegheny County created 24 years ago remained the same.

No longer. The county's Board of Health finally updated the rules on Wednesday, making changes that will bring long-term health benefits to the region. Starting Feb. 7, the health department will be able to use up-to-date science when reviewing applications for new permits from refineries, chemical manufacturers, power plants and other industrial facilities. In addition to air toxics any new facility might emit, the cumulative effect from nearby sources also will be a factor.

The guidelines will not necessitate changes at existing facilities, and they give businesses flexibility by allowing them to offset new or increased emissions by reducing other sources.

Reaching this milestone was not easy. A committee made up of environmentalists, industry officials, academics and regulators worked for two years, compromising and building consensus before recommending the new code in June. More tweaks were made after input from businesses and the public.

The guidelines may not be perfect, but they are a significant improvement over the status quo.