STOKENCHURCH, England — A British emissions testing firm has declared pollution from tire wear can be significantly worse that tailpipe emissions, but its testing methods and findings are being questioned by the European Tire & Rubber Manufactuers Association (ETRMA).
Stockenchurch-based Emissions Analytics Ltd., an independent testing firm specializing in measuring real-world emissions and fuel efficiency, said "non-exhaust emissions" — tire-wear particles, brake wear, road debris, etc. — can be up to 1,000 times worse than emissions from exhaust, the impact of which has been diminished due to tighter emissions controls and the switch to hybrid and electric vehicles.
"Our initial tests reveal there can be a shocking amount of particle pollution from tires," Senior Researcher Richard Lofthouse at Emissions Analytics said, noting that non-exhaust emissions are not regulated.
"It's time to consider not just what comes out of a car's exhaust pipe but particle pollution from tire and brake wear."
The problem, Emissions Analytics said, is compounded by the rising number of larger, heavier vehicles, such as SUVs, on the roads.
In its comments, the ETRMA noted that the tire industry — through the Tire Industry Project (TIP), which is under the umbrella of the World Business Council for Sustainable Development (WBCSD) — is supporting research into the presence and environmental impact of these particles.
The ETRMA also pointed out that its analysis of the tire-wear rate results of Emissions Analytics' driving test found that they "do not reflect normal driving conditions and go far beyond the toughest realistic driving behavior."
In addition, the ETRMA said Emissions Analystics used a fully loaded vehicle fitted with "low quality" tires and incorporated "high speeds and excessive cornering" in its testing, elements it said "underscores the unrealistic nature of the driving test and its results. ...."
Emissions Analytics said emissions commonly are measured according to their size with Particulate Matter 2.5 and Particulate Matter 10 being two commonly used thresholds. PM2.5 is described by the U.S. Environmental Protection Agency as "fine inhalable particles" that are 2.5 micrometers or smaller. while PM10 are "inhalable particles" generally 10 micrometers or smaller.
Examples of PM2.5 include combustion particles, organic compounds and metals, while examples of PM10 include dust, pollen and mold. By comparison, human hair is typically 50 to 70 micrometers and fine beach sand is 90 micrometers, the EPA said.