Thanks in part to the dogged efforts of Environmental Defense, the California Air Resources Board (CARB) unanimously approved a measure in late February to regulate harmful diesel emissions from back-up generators (BUGs). These huge engines -- often as large as those found in Greyhound buses -- provide electricity for places like factories, schools and hospitals during critical emergencies like blackouts or earthquakes when other power sources fail. Until now, BUGs have not been required to have emission controls, unlike other types of diesel engines.

These engines spew out a witch's brew of smog-forming chemicals, fine particles and cancer-causing toxins. The dangerous air pollutants and fine particles that make up diesel exhaust contribute to a host of public health hazards, including asthma - which is one of the most visible and worrisome impacts of air pollution and especially affects children.

Asthma is one of the fastest-growing chronic diseases in the United States, and asthma rates among children under the age of four have skyrocketed over the past 20 years. "Cleaning up these engines is a big step in the right direction for clean, healthy air and protecting our children from asthma attacks," says the director of our Health program John Balbus, MD, MPH.
 
The new rules, which take effect in 2005, mandate that new engines meet stringent clean-air rules (to reduce fine particle and soot emissions by as much as 85%) and that existing engines either be retrofitted or their hours of operation be shortened.

Smaller, Closer, Dirtier

Passage of this measure -- part of a broader package aimed at tightening regulations for diesel exhaust statewide -- marks the culmination of several years of hard work by our Oakland staff, starting with the release of our 2002 report: Smaller, Closer, Dirtier: Diesel Backup Generators in California and the launch of our interactive web tool. 

Our ground-breaking report, authored by our Nancy Ryan, Kate Larsen and Peter Black, brought into sharp focus the public health dangers of BUGs' unregulated emissions. Some very disturbing trends our study found were that BUGs tend to be located in heavily populated areas, near where people live, work and go to school; disproportionately affect the poor, minorities and the elderly; and affect the health of more than 150,000 schoolchildren statewide.

Getting Our Children Out of Harm's Way

Immediately after the report's release, our staff attended countless workshops, testified at meetings and worked with CARB staff to shepherd the bill through the rigorous process leading to its passage, making sure that the core of the bill's health-protecting provisions stayed intact

We played an instrumental role in winning the key provision that all BUGs located within 500 feet of a school are to be retrofitted to meet the cleanest standards or not run during school hours when children are present. Larsen, our key policy advocate for cleaning up diesel in California, says the clincher in the deal was just before the vote, when industry people complained about this provision. In response, a board member (who is also a medical doctor) chastised the group:  "Don't tell me you'd want your five-year-old playing next to one of those things!"

"This is a huge victory for clean air and public health," says Larsen. "These engines are almost completely unregulated across the United States, and because California is often at the forefront of efforts to clean up air pollution, we hope this bill will pave the way for nationwide emission standards for diesel-powered electrical generators and other stationary diesel engines."

Find Out More

• Our toolbox: BUGs in California
• Our report: Smaller, Closer, Dirtier  (August 2002)