Department of Environmental Conservation

D E C banner

DEC's Air Toxics Monitor - Albany South End

Air quality has improved over the past thirty years and as a result, New Yorkers breathe cleaner air and face lower health risks. But, there is still work to be done for air toxics. While the concentrations of air toxics in Albany's South End neighborhood are at levels considered to be good, some pollutant concentrations are above our air quality goals for all of New York's neighborhoods - including Albany's South End.

What are air toxics?

Air toxics are air pollutants that are known or suspected to cause cancer or other serious health effects. For example, inhaling (or breathing in) toxic air pollutants may increase your chances of experiencing health problems such as reproductive effects and birth defects, worsen asthma and cardiovascular health effects or cause harmful environmental effects.

Air toxics are released by actions we take every day like driving our cars, riding the bus, heating our homes or work space. Because these sources are very common, air toxics are found everywhere in the State. But the risk of adverse health effects from exposure depends on pollutant levels and the risk generally increases with increasing pollutant levels.

Monitoring Results

Air toxics monitoring began in March of 2015 in Albany's South End neighborhood. Air samples are collected over a 24-hour period every six days and evaluated for volatile organic compounds (VOCs) (such as benzene and 1,3-butadiene) and carbonyls (such as acetaldehyde and formaldehyde).

All 52 air toxics (42 VOCs and 10 carbonyls) from the South Albany monitor are available online. A more focused look at benzene, including historical concentrations, is also available.

DEC is primarily concerned with eight of the 52 air toxics collected in the Albany South End neighborhood. These eight are released from burning petroleum fuels in vehicles, space heating and the transport and movement of gasoline and crude oil.

Table 1. South Albany Air Concentrations for
Eight Air Toxics - 2015
Air Toxic 2015 Annual
Average (µg/m3)
2015 Range of 24-hour (daily)
Concentrations (µg/m3)
1,3-Butadiene 0.053 0.015 - 0.20
Acetaldehyde 1.7 0.38 - 4.0
Benzene 0.76 0.20 - 1.9
Ethylbenzene 0.29 0.043 - 1.2
Formaldehyde 2.6 0.64 - 6.0
m,p-Xylene 1.2 0.17 - 5.3
o-Xylene 0.44 0.074 - 1.8
Toluene 1.8 0.27 - 5.6

Note: the annual average concentration was calculated using all daily samples with detected measurements, divided by the number of detected samples.

Table 1 shows the 2015 annual average and range of daily (24-hr) concentrations for the eight air toxics from the Albany South End monitor. When looking at each individual air toxic, we see that the annual average is in the lower range of concentrations. Over the course of the monitoring year, we expect concentrations to vary due to a variety of factors such as variations in traffic, facility operations and meteorology. Since the average is in the low range, higher concentrations are rare.

Although there is variability in the daily results, Figure 1 shows that the average concentrations in Albany South End are similar to averages found at other monitors in the State's network for 2015. The type of location (such as urban or rural) is illustrated because we expect similar type sources in each location. The range of averages is pretty close for each air toxic which means each location has common sources like traffic. Formaldehyde shows a wider spread in concentrations and will be discussed in greater detail in the Risks in Perspective section.

Figure 1. 2015 Annual Average All DEC Monitors

Graph showing concentrations by location, source, and air toxic

What is the meaning of health risk?

Exposure to toxic air pollutants can increase your health risks. Health risks are a measure of the chance, or probability, that a person will experience health problems at some point in their lifetime. So if you live near a factory that releases chemicals that are known to cause adverse health effects, your risk of experiencing a health effect could increase. The goal of DEC's Division of Air Resources is to keep health risks to a level as low as possible.

How does the Division of Air Resources (DAR) assess risk?

Risk is assessed by comparing the 12 month averages from our monitoring data to our annual guideline concentrations (AGCs). AGCs are established by using the most conservative and scientifically valid health-based air concentration values developed by DAR or others, such as the US Environmental Protection Agency (EPA) or the New York State Department of Health (NYSDOH). AGCs are set at an outdoor (ambient) air concentration considered to represent very low health risk. AGCs were developed to protect the public's health from adverse effects which may be associated with continuous, long-term (e.g., lifetime) exposure to an outdoor air pollutant. These values do not account for other exposures such as indoor or occupational sources of toxic air pollutants. AGCs are used to assess the acceptability of proposed new air pollution sources during the permitting process, and to evaluate the results of ambient air monitoring studies that measure the cumulative impact of sources of air pollution in an area.

The guideline concentrations are not bright lines between air concentrations that cause health effects and those that do not. They provide a measure of the likelihood that people might experience adverse health effects and that information is used to help guide decisions about reducing community exposure to air pollution.

DAR's risk characterization process

Risk is something we all understand. In fact, we assess risk every day. What is the risk of driving, walking or taking a bus to work? Does the risk change when it is dark or the roads are wet or snow covered? Figure 2 provides examples of risks for some familiar events from high to low occurrences. The events are expressed as the chance they could occur over a person's lifetime.

Figure 2. Risks in Perspective

Graph comparing various risks as chances of occuring over a person's lifetime

Assessing risk from exposure to chemicals is similar. It is a process of identifying the type of air toxic, analyzing the risk from exposure and determining how large that risk is to people. The process involves these steps:

  • The toxicity of the chemical is examined. How toxic is the chemical? Can it cause effects in humans? Is it toxic in small or large amounts? Does it cause harm immediately (acute) or years later (chronic)?
  • Who will be exposed in their daily life to the chemical is considered. Can people be exposed to the chemical in the environment? Who is exposed - a small child or adult - an elderly or sick person? How much of the chemical are people exposed to and for how long? Do we have monitored or modeled concentrations for the chemical?
  • Is there an association between exposure and adverse health effect? This estimates how different levels of exposure to the air toxic change the likelihood and severity of adverse health effects and your risk.
  • What is the extra risk to health? This combines the toxicity of the chemical and exposure to the chemical to provide an understanding of the type and magnitude of harmful effect that a particular chemical could cause under specific conditions. This step is also called risk characterization and factors that complicate this process include a person's lifestyle (e.g., diet, exercise and smoking habits) and underlying health conditions (e.g., stress, asthma and high blood pressure). Ideally, we would like to eliminate all pollution and its risks, but this is not a realistic expectation given the widespread use of chemicals and fuels in everyday life.

Health Effects

There are two potential adverse health outcomes from lifetime exposure to high concentrations of air toxics: cancer or non-cancer endpoints. Non-cancer endpoints include reproductive, neurological, respiratory and cardiovascular effects. Both the non-cancer and cancer AGCs are derived from occupational and/or animal exposure studies to determine air concentrations that are associated with very low or no adverse health effects during a lifetime of continuous exposure. The AGC is often modified - to be very health protective - from the experimental value to account for uncertainties for both the non-cancer and cancer health endpoints.

Cancer - We characterize risk of exposure to cancer-causing chemicals as a measure of the likelihood of developing cancer over a lifetime or the estimated excess cancer risk. This is an extra chance of developing cancer above the other risks contributing to the development of cancer. Cancer risk is primarily based on individual risk factors such as tobacco and alcohol use, diet (fried foods, red meat), physical inactivity, obesity, stress and sun exposure. Other important individual risk factors are age, workplace exposures, family history and personal medical history, including radiation exposure and infections.

AGCs based on cancer health effects are defined as chemical concentrations in air that are associated with an estimated excess lifetime cancer risk of 1-in-a-million (or 1 person in 1,000,000 exposed individuals). There is general consensus among the scientific and regulatory communities as to what level of estimated excess cancer risk is acceptable. Under the 1990 Clean Air Act, the acceptable cancer risk range used by the EPA to make regulatory decisions regarding the need for further air pollution reductions from sources ranges from 1-in-a-million to 100-in-a-million. Cancer risk above 100-in-a-million usually results in measures to reduce exposure. The DAR defines acceptable cancer risk as a range between 1-in-a-million to 10-in-a-million. The 1-in-a-million to 10-in-a-million risk range used by DAR to make regulatory permitting decisions about the need to consider further air pollution controls for sources is more conservative than EPA's acceptable level of concern between 1-in-a-million to 100-in-a-million.

Non-Cancer - For chemicals that do not cause cancer, but do cause other health effects, a different approach is taken.

First, an exposure level where the chemical does not cause harmful health effects is determined and various federal authoritative agencies1 have determined this level, based on animal or human studies.

Second, these levels are then lowered to be more health protective, by as much as 100- or 1000-times, to account for uncertainties. Uncertainties might include whether the effects in animals can be used to estimate the likelihood of effects in humans or whether the effects of high concentration exposures from animal or human studies can be used to estimate the effects of the low exposure levels commonly found in the environment.

These health protective levels, called reference concentrations, assume that people in the area, including sensitive populations such as children, are likely to be without an appreciable risk of harmful effects during a lifetime of exposure. DAR uses these reference concentrations for chemicals that cause non-cancer effects. The reference concentrations are referred to as non-cancer AGCs and they vary from one air toxic to another. To evaluate the potential of a non-cancer chemical to cause health effects, the annual (or 12 month) average is compared to the non-cancer AGC. If the toxic air pollutant average is equal to or less than the AGC then the chance that the chemical could cause health effects will be low.

Eight Air Toxics - Risks in Perspective

The eight air toxics of interest from Albany's South End monitor were evaluated in terms of the risk of causing health effects. The estimated risks are shown in Table 2 for the four air toxics with cancer health effects. All risks are characterized as low with the exception of formaldehyde. Ambient concentrations of this air toxic are above the 10-in-a-million cancer risk everywhere in the State, even in rural areas. The Statewide average cancer risk estimate from ambient concentrations of formaldehyde is 47-in-a-million, which is slightly above the risk estimate in South Albany of 43-in-a-million. This air toxic is very common in outdoor air because it primarily comes from the reaction of sunlight and volatile organic compounds released from combustion and vegetative sources (such as trees). Other sources which release formaldehyde are diesel-powered engines.

Table 2. Risk Characterization - South Albany Air Toxics with Cancer Health Effects
Air Toxic 2015 Annual
Average (µg/m3)
Annual
Guideline
Concentration (µg/m3)
Cancer Risk Estimates
(# excess cancers
per 1,000,000)*
Risk
Characterization
1,3-Butadiene 0.053 0.033 1.6 Low
Acetaldehyde 1.7 0.45 3.9 Low
Benzene 0.76 0.13 5.8 Low
Formaldehyde 2.6 0.06 43 Moderate

* Number of estimated excess cancers per 1,000,000 people equally exposed.

Table 3 shows the results for the four air toxics with non-cancer health effects. All hazard quotients are well below 1 and the risks from exposure to these air toxics would be very low.

Table 3. Risk Characterization - South Albany Air Toxics with Non-Cancer Health Effects
Air Toxic 2015 Annual
Average (µg/m3)
Annual Guideline
Concentration (µg/m3)
Annual Average
Compared to AGC
Risk
Characterization
Ethylbenzene 0.29 1000 less than 1 Low
m,p-Xylene 1.2 100 less than 1 Low
o-Xylene 0.44 100 less than 1 Low
Toluene 1.8 5000 less than 1 Low

In conclusion, the risk of health effects for the eight air toxics based on the levels measured in Albany South End in 2015 is low to moderate.

__________

1 DEC's primary resource is the US Department of Health and Human Services' National Toxicology Program.