EPA released a new National Ambient Air Quality Standard (NAAQS) for nitrogen dioxide (NO₂) in January. This new one-hour standard is aimed to protect public health from peak short-term exposures, especially along busy city streets and highways where NO₂ exposure is the most likely. According to the EPA, NO₂ exposure has been linked to impaired lung function and increased respiratory infections, especially in people with asthma.

NO₂ is one of a group of highly reactive gasses. It forms quickly from emissions from cars, trucks, buses, power plants, and off-road equipment. In addition, NO₂ contributes to the development of ground-level ozone and fine particle pollution.

Read more about the nitrogen dioxide standard…

Nuisance odors are a complex and subjective issue, often resulting in odor complaints directed at industrial or agricultural facilities such as wastewater treatment plants, landfills, large scale composting facilities, or animal feed operations. At these types of facilities, most odorous chemical compounds are produced under anaerobic conditions. Contrary to popular belief, nuisance odors themselves do not generally cause long term illness or any direct health effect.  In other words, if the source of the odor is taken away, any associated illness symptoms (e.g. nausea) will also go away. Therefore, unlike investigations centered on human health risk, investigations involving nuisance odor are governed by the perception of the receptor. A person’s perception of odor is related to the human olfactory system, which can vary widely from person to person; what smells bad to one person might not have an odor at all to someone else. To further confuse the issue, there is a distinct lack of odor regulations, and those that exist are extremely vague. The EPA defaults to the state level for nuisance odors, and most states defer to the county or local level.

Odor is a parameter which may be measured unto itself, following established ASTM and/or European Standards. This approach will quantify how odorous a sample is, ranking it on a relative scale with units of dilution to threshold (D/T).

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