Today we review research into the impact of roadside emissions for people living near (within 50 m) of major highways in Southern California. While various policies have been put in place recently and into the future to reduce PM2.5 and greenhouse gas emissions, this study concentrated on the specific health impacts from roadside gases as they affect coronary heart disease. Results indicate that although emissions have lessened that more and more people live closer to the highways so that the health impacts become greater. Several options are suggested to alleviate this including a switch to zero emission electric vehicles and putting a buffer between the highways and residential areas.
Key Quotes:
“Emerging evidence suggests a causal link between near-roadway air pollution (NRAP) and coronary heart disease (CHD) mortality and morbidity”
“The total SoCAB [California’s South Coast Air Basin ] population was 15.5 million in 2008 and is projected to increase by approximately 3 million in 2035. However, the proportion ≥ 45 years at risk for CHD is expected to increase from 35% in 2008 to 43% in 2035”
“the proportion of the population living within 150m from a freeway or 50m from a major road is expected to increase from 8.3% to 10.9% from 2008 to 2035 “
“The overall pattern of changing exposure and NRAP-attributable CHD was generally similar across all SoCAB counties. Traffic density and EC levels were highest in Los Angeles County and lowest in Riverside County and are projected to decrease in all four counties from 2008 to 2035.”
“In contrast, the proportion living near a major road is projected to increase in all counties during the same period.”
“Estimates of the 2008 preventable CHD mortality due to NRAP among the ≥45 years population in the SoCAB varied from 2.4% (430 deaths), based on effects of residential proximity to a major road, to 6.8% (1,300 deaths), based on emissions-weighted traffic density”
“The 2035 greenhouse gas reduction–planning scenario is projected to result in reduced population exposure and reduced PAF for PM 2.5, traffic density, and EC (but not for residential proximity to major roadways)”
“if this planning scenario increases the population exposed to NRAP by placing people closer to busy roadways, they may be put at increased CHD risk, unless vehicle emissions were to decrease more substantially than currently anticipated”
"Variants on the planning scenario, such as policies to develop a zero- or close-to-zero-emission vehicle fleet, could optimize health co-benefits of greenhouse gas reduction. Another approach might be to encourage buffers between major traffic corridors and high-density development through zoning and other land use policies. “
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