Toxic Air Pollution in the Phoenix Metro Area
Air monitoring conducted in the Phoenix metro area as part of the Joint Air Toxics Assessment Project in 2005 found very high levels of a number of toxic chemicals, but the public has been kept in the dark about its disturbing findings. The study is posted here. Click here to view the .pdf file.
At a spring 2012 Motorola Superfund Site meeting in Phoenix, Gerry Hiatt, EPA toxicologist, made a presentation about the relative risks posed to human health by these levels in certain areas. As you can see, they far exceed the “acceptable” one in a million standard for cancer risk. He stated at the meeting that the air in the Phoenix metro area is one of the more polluted in the country, as similar monitoring has been conducted throughout some major metropolitan areas in the US.
Hiatt’s presentation is posted here. Click here to view the .pdf file.
Some of Hiatt’s conclusions:
VOCs higher in Phoenix compared to typical U.S. urban areas:
Highest risk outdoor VOCs in Phoenix*(greater than 1 in one-million lifetime cancer risk):
Formaldehyde –34 in one-million
Benzene –8 in one-million
1,3-butadiene –7.5 in one-million
Chloroform –3.6 in one-million
Acetaldehyde –3.4 in one-million
PCE –3 in one-million
TCE –0.23 in one-million
Greenwood / JLG Supersite / South Phoenix / West Phoenix
MAP OF JATAP SAMPLING SITES
Annual Average Concentrations
How Do Air Toxics Concentrations Compare with Typical National Levels?
According to the JATAP findings, Phoenix area urban concentrations of 1,3-butadiene, acetaldehyde, formaldehyde, chloroform, benzene, and tetrachloroethene were typically on the high end of the national urban scale (i.e., above the 75th percentile). Other air toxics concentrations were typically within the interquartile range of national concentrations (25th to 75th percentile). Note that vinyl chloride concentrations were typically below the MDL at all sites and are plotted at MDL/2.
Hexachlorobutadiene, a chemical associated with the manufacturing of tires, was found in high levels at some of the sampling locations (west Phoenix, South Phoenix, and on the Gila River Indian Community), but not all of them. There are no tire manufacturing facilities in the Phoenix metro area. The highest levels found were in west Phoenix, at over 58 times the “acceptable cancer risk level.” There is no evidence that after finding these shockingly high levels that anything was ever done by the ADEQ or EPA to determine the source(s) of this toxic chemical, or to reduce the levels.
This JATAP study documents that TCE, PCE, chloroform, and vinyl chloride are in the air in the Phoenix metro area. Clearly, these chemicals are off gassing and emerging from the ground above the plumes of chemical contamination that start with the Motorola 52nd Street Superfund Site (52nd Street to 7th Avenue) and go on to the West Van Buren Study Area, which is in the WQARF Program (7th Avenue to 91st Avenue). The JATAP study erroneously attributes the TCE, vinyl chloride, and some of the other toxic chemicals found to “stationary sources,” a term used for air pollution coming out of smokestacks or from a facility. There are no industrial sources of these chemicals in the Phoenix metro area. (TCE was banned from industrial uses decades ago.) [TCE (Trichloroethylene) degrades or breaks down into vinyl chloride and/or chloroform.]
The EPA is here sampling soil gases and air inside some homes in the east end of the 52nd Street Motorola Superfund Site, where the depth to groundwater is quite shallow, to determine the extent of how much TCE and its break down components, vinyl chloride and chloroform, are seeping into homes as the toxic chemicals rise from the plume of contamination and emerge into the air.
One of the shocking findings is that South Phoenix has some of the highest levels of TCE, but there is no plume off gassing there. Instead, as South Phoenix and the Salt River bed are the lowest points, geographically and topographically, in the Phoenix metro area, the fumes that are emitted from the plumes and contaminated soils are slumping to, and pooling in, South Phoenix.
The communities on or adjacent to plumes of TCE and PCE all had high levels of these carcinogens in their ambient air. West Phoenix had the highest levels and concentrations. This is chronic, low-level exposure. Since the air in Phoenix tends to slide down gradient to the Salt River bed, pool there, then blow back and forth along the riverbed, South Phoenix, while not the site of one of these plumes, is the unlucky recipient of the seeping and pooling of some these fumes out of the contaminated plumes. But these chemicals also did find their way many miles away to the rural control site in Queen Valley, where there are no plumes of TCE underground, or any industrial sources. So there is widespread air contamination from TCE, PCE, vinyl chloride, and other chemicals emanating from these underground reservoirs of carcinogens, traveling many miles with prevailing winds.
Of course, no one in the communities where the high levels were found was ever told, and nothing has been done to mitigate the problem.
EPA has set a standard for cancer risk, with a one in a million chance in a lifetime of exposure considered “acceptable.” But the JATAP monitoring had found in the high end of the monitoring levels, formaldehyde at 34 times this standard; benzene at 8 times this standard, 1,3 butadiene at 7.5 times this standard, chloroform at 3.6 times this standard, acetaldehyde at 3.4 times this standard, PCE at 3 times this standard, and TCE, with the new standard expected to be dropped from 5ppb to 1-2ppb as an acceptable standard, also above the one in a million chance in a lifetime of exposure. And, remember, citizens are being subjected to all of these carcinogens, not just one. Some of these chemicals are attributed to “mobile sources,” or vehicular traffic burning hydrocarbons.
And it calls into question the value of cancer risk standards. If there are levels many times the “acceptable cancer risk,” then why isn’t anyone doing anything about it or even informing and/or warning the people who live in these more polluted areas?
When DWAZ approached the Office of the Mayor of Phoenix about this, it was referred to the City of Phoenix’ Office of Environmental Programs. The manager of that department stated that the levels “weren’t high every day.” When we asked if that was the City’s and the Mayor’s final response, it was then referred to Colin Tetreault, Senior Sustainability Policy Advisor, Office of the Mayor. After several months, there is no response.