National Drinking Water Database
Benzo[a]pyrene in Arizona
Benzo[a]pyrene is a polycyclic aromatic hydrocarbon that contaminates drinking water from leaching coal tar coatings on water distribution pipes and storage liners; it is also a product of combustion. [read more]
Benzo(a)pyrene is a polycyclic aromatic hydrocarbon (PAH) that forms during the incomplete combustion of coal, oil, gas, wood, garbage, tobacco products and the barbequing of meats and vegetables. PAHs are found in asphalt and are also used by industrial chemical factories (Agency for Toxic Substances and Disease Registry (ATSDR) 1995c).
Environmental releases of benzo(a)pyrene are reported as part of releases of the broad class of PAH chemicals. According to the Toxics Release Inventory (TRI), millions of pounds of PAHs are released by industrial facilities annually into air, water and onto land (U.S. Environmental Protection Agency (USEPA) 2009i). Additionally, large amounts of PAHs are emitted to the atmosphere during the combustion of automotive fuel.
Benzo(a)pyrene and other PAHs have low solubility in water. They usually enter drinking water from coal-tar coatings of drinking water distribution pipes, used to protect the pipes from corrosion (World Health Organization (WHO) 2004a).
The National Toxicology Program lists benzo(a)pyrene as a known animal carcinogen and as "reasonably anticipated" to be a human carcinogen (National Toxicology Program (NTP) 2002a). In animals, benzo(a)pyrene has been shown to produce tumors in the lung, skin, stomach, mammary glands and uterus (NTP 2002a). In workers exposed to high air PAH concentrations and/or frequent skin exposure to PAHs, increased risks of cancers of the skin, lung and respiratory tract, bladder and kidney have been observed (ATSDR 1995c). Benzo(a)pyrene has also been shown to interact with human placenta and it is suspected to reduce neonatal birth weight (ATSDR 1995c). PAHs have also been detected in the milk of nursing mothers and in cow's milk (Somogyi 1993; ATSDR 1995c; Hazardous Substances Data Bank (HSDB) 1998).
The Most Polluted Communities in Arizona
3 water utilities reported detecting Benzo[a]pyrene in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies
Ranked by highest average Benzo[a]pyrene level
|Rank||System||Population Served||Positive test results of total reported tests||Average Level|
|1||Chino Meadows Ii|
|2,500||1 of 1||0.04 ppb|
|2||City of Chandler|
|180,000||1 of 36||< 0.01 ppb|
(0 to 0.02 ppb)
|43,433||1 of 20||< 0.01 ppb|
(< .01 to 0.008 ppb)
Health Based Limits for Benzo[a]pyrene
|Maximum Contaminant Limit Goal (MCLG)||A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.||0 ppb|
|EPA Human Health Water Quality Criteria||Water quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.||<0.01 ppb|
|California Public Health Goals||Defined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.||<0.01 ppb|
|One in one million (10-6) Cancer Risk||The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 1,000,000. Source: U.S. Environmental Protection Agency.||<0.01 ppb|
|Maximum Contaminant Limit (MCL)||The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.||0.2 ppb|
|One in ten thousand (10-4) Cancer Risk||The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 10,000. Source: U.S. Environmental Protection Agency.||0.5 ppb|
Violation Summary for Benzo[a]pyrene in Arizona
Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in Arizona since 2004
|Violation Type||Number of Violations|
|Failure to monitor regularly||15|
|Failure to monitor: Check/Repeat/Confirmation sampling||1|