DEQ's Innovative Vehicle Inspection Program Gets Results

Environmental Challenge

In the early 1970s, downtown Portland violated the national health standards for carbon monoxide an average of once every three days. In the Medford area, national health standards for carbon monoxide were violated 35 times in 1985. Both cities also exceeded the standard for ozone smog at least 40 days per year.

High levels of carbon dioxide and smog aggravate asthma, decrease lung capacity, impair the immune system and contribute to increased hospital emergency room visits.

Success Story

Air pollution in the Portland and Medford areas has been dramatically reduced because of DEQ's Vehicle Inspection Program.

Oregon was the first state in the nation to authorize a vehicle inspection program. Within two years of beginning vehicle emission testing in Portland in 1975, carbon monoxide levels dropped 20 percent and ozone pre-cursors—nitrous oxide and volatile organic compounds—declined 15 percent.

Thanks to vehicle inspection and other pollution reduction strategies, there hasn't been a single carbon monoxide violation in downtown Portland since 1985.

On average, vehicles that fail emissions tests produce up to four times as much pollution as those that pass.