The evidence comes in a new U.S. Environmental Protection Agency report summing up the latest science about nitrogen dioxide pollution -- the very sort of noxious emissions that have spewed (and continue to spew) from VW's cheater tailpipes. Link to new EPA report .
The bottom line: exposure to nitrogen dioxide pollution is much worse than we realized even a half-dozen years ago.
And, to be fair, Volkswagen is not the only culprit. This report also underscores the need for tougher national emission standards for big-rig trucks -- something that the state of California and Northeastern states have been advocating.
EPA last dealt with the issue of ambient nitrogen dioxide in 2010, when the agency made only modest changes to a standard set in 1971. Clean Air Watch and our friends at the American Lung Association said then that EPA had been too timid -- and we made the prophetic observation that this suggested EPA might be too timid in dealing with ozone also. Greenwire on EPA and NO2
Since then, the scientific evidence continues to pile up to back our case that tougher standards are indeed needed to reduce people's exposure to emissions that could prompt asthma attacks and possible other health problems.
Here are a few quick summary points from EPA's "integrated science assessment" of the health effects of exposure to this pollutant:
Evidence for asthma attacks supports a causal relationship between short-term
NO2 exposure and respiratory effects. Evidence for development of asthma
supports a likely to be causal relationship between long-term NO2 exposure and
respiratory effects. These are stronger conclusions than those determined in the
2008 ISA for Oxides of Nitrogen.
There is more uncertainty as to whether short-term or long-term NO2 exposure is
related to cardiovascular effects, diabetes, reproductive and developmental
effects, total mortality, and cancer.
People with asthma, children, and older adults are at increased risk for
NO2-related health effects.
People living or spending time near or on roads, low socioeconomic status
populations, and nonwhite populations may have increased NO2 exposure.
The first year of data from the U.S. near-road monitoring network indicate that
near-road sites tend to have higher NO2 concentrations on average but do not
always have the highest 1-hour NO2 concentration within an urban area.
Epidemiologic studies link asthma attacks and asthma development to NO2
measures that appeared to well represent exposure, including personal measures
and concentrations where participants live or spend a lot of time.
No specific NO2 averaging time, duration, or age of exposure is more strongly
associated with asthma attacks or asthma development. It is not clear whether
there is an exposure concentration below which effects do not occur.
Here is a quick link to the comments, noted above, from Northeastern states about the need for tougher truck emission standards:Northeastern states urge tougher truck NOx standards
As for its new review of whether tougher NO2 standards are needed, unfortunately the U.S. EPA is not scheduled to make a final decision before 2017. EPA work plan on NO2
Let's hope this new science assessment will make this issue a higher priority within the EPA.