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National Drinking Water Database

National Drinking Water Database - Chemical Contaminants

Chromium (total)

Status: Regulated - EPA has established a maximum legal limit in tapwater for this contaminant.

Chromium is a metal that pollutes drinking water due to discharge from steel and pulp mills and erosion of natural deposits. [read more]

Chromium III or VI

Chromium is a naturally occurring element used in the production of metal alloys (with nickel, tungsten, cobalt and steel), ceramics, salts and pigments. Chromium is also used in leather tanning, as a catalyst for chemical synthesis reactions, and as a wood preservative (for example, chromated copper arsenate). Before 1961, chromium was mined in the U.S. as chromite ore, but it is now mostly imported into the U.S. from other nations, mainly South Africa (37 percent), Russia (18 percent) and Turkey (13 percent) (Hazardous Substances Data Bank (HSDB) 2002b).

Chromium can exist in several different forms. Depending on the form it takes, it can be a liquid, solid, or gas. The most common forms are chromium 0 (metallic chromium), chromium III and chromium VI (also known as hexavalent chromium). Chromium VI is a highly toxic air and water contaminant that can damage the respiratory system and cause cancer. Ingesting high levels of chromium VI may result in anemia or damage to the stomach or intestines. Chromium III is an essential nutrient (Agency for Toxic Substances and Disease Registry (ATSDR) 2008b).

Chromium is released into the environment from the combustion of natural gas, oil and coal, and from its use in several industries including: industrial chemical production, steelworks, electrometallurgy and copper smelting. Chromium is also released into the environment from chromium-treated wood and chromium-containing paint pigments (U.S. Environmental Protection Agency (USEPA) 2002f).

In 2002, industrial facilities reported releasing 9,311,530 pounds of chromium into U.S. water, air, and land (USEPA 2009i). The reported releases of chromium underestimate the volume of chromium that was released into the environment, because the volume of chromium used as a wood preservative and as a paint additive is not included in these official estimates. Chromium has been found in at least 1,127 of the 1,669 National Priorities List sites, which are areas of known releases of hazardous substances, pollutants, or contaminants throughout the U.S. and its territories, also known as the Superfund sites (ATSDR 2008b; USEPA 2009c).

Hexavalent chromium is a known human carcinogen according to the National Toxicology Program, causing lung cancer in workers in the chromium industry (National Toxicology Program (NTP) 2002a). Oral exposure to hexavalent chromium has been associated with substantially elevated stomach cancer mortality in a study of residents in Chinese villages with hexavalent chromium-contaminated drinking water (Beaumont 2008). Ingestion of chromium VI in drinking water also produced sever gastrointestinal effects such as oral ulcers, diarrhea, abdominal pain, indigestion, vomiting and bloody diarrhea (ATSDR 2000a, 2008b).

According to the U.S. EPA, short-term exposure to chromium-contaminated drinking water can cause skin irritation and ulceration, and long-term exposure can cause damage to kidneys, the circulatory system, nervous system and skin (USEPA 2002f).

Hexavalent chromium exposure in workers has been linked to chromosome aberrations and damage to the pharynx, larynx, kidney, heart and liver (ATSDR 2000a, 2008b). Changes in white blood cell counts, decreased hemoglobin, increased bleeding times, stomach cramps, and stomach and intestinal ulcers have also been reported. Greater incidence of complications during pregnancy and childbirth has been reported in chromate-exposed Russian dichromate manufacturing factory workers. Higher incidences of diarrhea, constipation, headaches, tiredness, lightheadedness and eye irritation has been reported among residents living near a chromium-contaminated area of Tokyo, Japan compared to people living in an uncontaminated area.

Hexavalent chromium-contaminated drinking water from Pacific Gas and Electric (PG&E) was reported in Hinkley, California and formed the basis for the movie, "Erin Brockovich." The case against PG&E ultimately resulted in the largest legal settlement in U.S. history - $333 million.

In August 2009, the California Office of Environmental Health Hazard Assessment proposed a new public health goal for hexavalent chromium in drinking water that is hundreds of times lower than the amount contaminating some water supplies (California Environmental Protection Agency. 2009a; Environmental Working Group (EWG) 2009). The draft public health goal for hexavalent chromium is set at 0.06 parts per billion (ppb). A public health goal is the level of a chemical contaminant in drinking water that does not pose a significant health risk (California Environmental Protection Agency 2009b).

The recommendation culminates a decade of debate among scientists trying to decide what concentration is safe to drink (Cone 2009). The 0.06 ppb health guideline proposed by California state scientists, if adopted by regulators, would reduce the risk of cancer caused by chromium VI in drinking water to one in one million, the point at which the state of California considers the danger to public health to be minimal (EWG 2009).

Trivalent chromium compounds are considerably less toxic than hexavalent compounds. Chromium III is an essential nutrient in the diet of humans and animals in very small amounts. Other forms of chromium are not needed by living organisms and all forms of chromium can be toxic at high levels. People who are allergic to chromium may have asthma attacks after breathing high levels of chromium III in air. Repeated or prolonged skin contact may cause irritation, skin allergy, itching, redness and an eczema-like rash (Australian National Pollutant Inventory 2005).

Chromium III occurs as dissolved compound in natural waters as a result of weathering of minerals in rocks and soils. However, industrial emissions are a significant contributor to overall chromium pollution in drinking water, because manufacturing, disposal of products or chemicals containing chromium, and burning of fossil fuels are all processes that release chromium to the air, soil, and water. Research by scientists at the U.S. Environmental Protection Agency demonstrated that chromium III is converted into more toxic chromium VI when tap water is treated with chlorine, thus increasing overall risk to human health (Ulmer 1986).

	Detected	Found above health guidelines	Found above legal limit
States	42	5	5
Water utilities	6,995	6	6
People Served	74,745,007	157,673	157,673

Health Concerns for Chromium (total):

Allergies/immunotoxicity
Cancer
Occupational hazards
Organ system toxicity (non-reproductive)
Ecotoxicology
Persistence and bioaccumulation

Chromium (total) Exposure by State

Water utilities in 42 states have reported detecting Chromium (total) in treated tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies.

State	Water Suppliers with Chromium (total) contamination		Water suppliers reporting Chromium (total) above health-based limits
State	Systems	Population	Systems	Population
California	851	20,419,202	1	156,500
Texas	784	5,865,920	1	660
Illinois	197	4,985,190	2	373
New York	263	2,490,835	1	70
New Hampshire	39	70,606	1	70
Florida	582	7,534,267	0	0
Arizona	368	3,964,932	0	0
Ohio	163	3,096,374	0	0
Wisconsin	725	2,976,633	0	0
Indiana	282	2,563,787	0	0
Nevada	63	2,233,353	0	0
Maryland	87	2,148,852	0	0
Pennsylvania	171	2,019,038	0	0
New Jersey	81	1,931,025	0	0
Missouri	523	1,641,662	0	0
Kentucky	45	1,385,900	0	0
Nebraska	381	1,293,073	0	0
Hawaii	42	1,075,246	0	0
Connecticut	74	921,138	0	0
Delaware	175	847,646	0	0
Utah	25	729,218	0	0
Massachusetts	50	705,404	0	0
New Mexico	192	649,723	0	0
Oregon	67	577,383	0	0
Maine	314	513,468	0	0
Idaho	80	453,994	0	0
Oklahoma	39	333,595	0	0
Arkansas	68	325,686	0	0
Alaska	106	321,964	0	0
South Dakota	64	203,593	0	0
Minnesota	7	164,892	0	0
Washington	30	163,304	0	0
Wyoming	1	58,182	0	0
Rhode Island	6	19,156	0	0
Alabama	5	18,733	0	0
Montana	20	15,212	0	0
North Carolina	14	10,323	0	0
Michigan	5	7,726	0	0
Iowa	2	4,172	0	0
West Virginia	2	2,762	0	0
Virginia	1	1,638	0	0
Vermont	1	200	0	0
Total	6,995	74,745,007	6	157,673

The Most Polluted Communities

6,995 water utilities reported detecting Chromium (total) in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by highest average Chromium (total) level

Rank	System	Population Served	Positive test results of total reported tests	Average Level (Range)
1	Hyde Park Terrace Apartments Poughkeepsie, NY	70	1 of 1	180 ppb (180 ppb)
2	Chester College of NE /Douglas NH	70	1 of 1	104.9 ppb (104.9 ppb)
3	Spanish Lakes Country Club Village Fort Pierce, FL	2,331	1 of 1	100 ppb (100 ppb)
4	Country Oaks Ocala, FL	92	1 of 1	100 ppb (100 ppb)
5	Esperanza Water Service Co Inc Pecos, TX	660	2 of 2	85.65 ppb (29.3 to 142 ppb)
6	Howell Water System Howell, UT	260	1 of 1	71.9 ppb (71.9 ppb)
7	Town of Wenden Wenden, AZ	650	1 of 1	70 ppb (70 ppb)
8	Tucker Acres Mutual Water Co. Calistoga, CA	200	1 of 1	60 ppb (60 ppb)
9	Village Green Mobile Home Park Kokomo, IN	210	1 of 1	57 ppb (57 ppb)
10	Indiantown Company Inc. Indiantown, FL	5,000	2 of 2	56.75 ppb (13.5 to 100 ppb)

Health Based Limits for Chromium (total)

Standard	Description	Level
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.	100 ppb
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.	100 ppb
Drinking Water Equivalent Level	A lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.	100 ppb
Children's health-based limit for 1-day exposure	Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.	1000 ppb
Children's health-based limit for 10-day exposure	Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.	1000 ppb

Testing Summary for Chromium (total)

Are tests routinely required for Chromium (total) by federal law?	Yes
Water suppliers reporting tests for Chromium (total) (2004-2009):	29,352 of 47,576
Average testing rate for water supplier reporting tests (2004-2009):	0.4 per year

Violation Summary for Chromium (total)

Data from the U.S. Environmental Protection Agency includes the following violations of federal standards for Chromium (total) since 2004

Maximum Contaminant Level Exceedance Violations	1
Monitoring Violations	1,182
Reporting Violations	0

Allergies/immunotoxicity

Type of concern:	Reference:
Human immune and respiratory toxicant or allergen - strong evidence	Association of Occupational and Environmental Clinics

Cancer

Type of concern:	Reference:
One or more animal studies show tumor formation at very low doses	RTECS^®- Journal of the National Cancer Institute 1955
One or more in vitro tests on mammalian cells show positive mutation results	RTECS^®- Toxicologist 2003
One or more in vitro tests on mammalian cells show positive mutation results	RTECS^®- Journal of the National Cancer Institute 1955
One or more in vitro tests on mammalian cells show positive mutation results	RTECS^®- Toxicologist 2008
One or more animal studies show tumor formation at moderate doses	RTECS^®- Zeitschrift fuer Krebsforschung 1942

Occupational hazards

Type of concern:	Reference:
Allowed workplace exposures restricted to low doses	RTECS^®- TLV/BEI,2005
Allowed workplace exposures restricted to low doses	RTECS^®- TLV/BEI,2006
Allowed workplace exposures restricted to low doses	RTECS^®- TLV/BEI,2007

Organ system toxicity (non-reproductive)

Type of concern:	Reference:
Classified as expected to be toxic or harmful	Environment Canada Domestic Substance List
Classified as medium human health priority	Environment Canada Domestic Substance List
One or more animal studies show broad systemic effects at low doses	RTECS^®- Gigiena i Sanitariya 1972
Limited evidence of toxicity	A Relational Database of Hazardous Chemicals and Occupational Diseases, 1990
Limited evidence of toxicity	US EPA, Air Risk Information Support Center
One or more animal studies show classified as toxic effects at moderate doses (low dose studies may be unavailable for this ingredient)	EPA Toxic Release Inventory PBTs
One or more animal studies show no adverse effects at high doses	EPA Toxic Release Inventory PBTs

Ecotoxicology

Type of concern:	Reference:
Wildlife and environmental toxicity	EPA Clean Water Act - Priority Pollutants
Not suspected to be an environmental toxin	Environment Canada Domestic Substance List

Persistence and bioaccumulation

Type of concern:	Reference:
Not suspected to be bioaccumulative	Environment Canada Domestic Substance List

Government, industry, academic studies and classifications

government/industry list/academic study	appears on list as	classification(s)
Association of Occupational and Environmental Clinics	CHROMIUM, NOT HEXAVALENT	• ARS
Association of Occupational and Environmental Clinics	CHROMIUM, NOT HEXAVALENT	• Asthmagen sensitizer
Association of Occupational and Environmental Clinics	CHROMIUM, NOT HEXAVALENT	• Asthmagen sensitizer
EPA Clean Water Act - Priority Pollutants	CHROMIUM	•Priority water pollutant under the Clean Water Act
Environment Canada Domestic Substance List	CHROMIUM	•This chemical was deemed a moderate human health priority and was flagged by CEPA for further attention. The chemical was flagged for suspected persistence.
EPA Toxic Release Inventory PBTs	CHROMIUM; CHROMIUM METAL	•Toxic, U.S. Environmental Protection Agency Toxics Release Inventory programs
EPA Toxic Release Inventory PBTs	CHROMIUM COMPOUNDS -- TRI	•Toxic, U.S. Environmental Protection Agency Toxics Release Inventory programs
A Relational Database of Hazardous Chemicals and Occupational Diseases, 1990	CHROMIUM	•Respiratory toxicity hazards: suspected
US EPA, Air Risk Information Support Center	CHROMIUM (III)	•Respiratory toxicity hazards: suspected
RTECS^®- TLV/BEI,2005	CHROMIUM	• occupationally related - ACGIH TLV (human TWA)
RTECS^®- TLV/BEI,2006	CHROMIUM	• occupationally related - ACGIH TLV (human TWA)
RTECS^®- TLV/BEI,2007	CHROMIUM	• occupationally related - ACGIH TLV (human TWA)
RTECS^®- Gigiena i Sanitariya 1972	CHROMIUM	• broad systemic - Broad systemic toxicity (rat LD50)
RTECS^®- Journal of the National Cancer Institute 1955	CHROMIUM	• cancer - blood tumor formations - equivocal (rat TDLo) • cancer - gastrointestinal tumor formations - equivocal (rat TDLo) • cancer - Tumors at site of application (rat TDLo)
RTECS^®- Toxicologist 2003	CHROMIUM	• mutagenic - Positive mutation assay: DNA Damage ( human lng)
RTECS^®- Toxicologist 2008	CHROMIUM	• mutagenic - Positive mutation assay: DNA Damage ( human lym)
RTECS^®- Toxicologist 2003	CHROMIUM	• mutagenic - Positive mutation assay: DNA Damage ( human lng)
RTECS^®- Zeitschrift fuer Krebsforschung 1942	CHROMIUM	• cancer - musculoskeletal tumor formations - equivocal (rabbit TDLo)

references

government/industry list/academic study	reference
Association of Occupational and Environmental Clinics	AOEC (Association of Occupational and Environmental Clinics). 2009. AEOC exposures codes and asthmagen designation.
EPA Clean Water Act - Priority Pollutants
Environment Canada Domestic Substance List	EC (Environment Canada). 2008. Domestic Substances List Categorization. Canadian Environmental Protection Act (CEPA) Environmental Registry.
EPA Toxic Release Inventory PBTs	EPA (U.S. Environmental Protection Agency). 1999. Toxics Release Inventory Program. PBT Chemical Rule.
Scorecard.org Toxicity Information	A Relational Database of Hazardous Chemicals and Occupational Diseases. Browse Haz-Map by Adverse Effects http://hazmap.nlm.nih.gov/hazmapadv.html, Nemery, B. Metal Toxicity and the Respiratory Tract. European Respiratory Journal. 3(2): 202-219. 1990.(Table 1: Summary of pulmonary toxicity of metals).
Scorecard.org Toxicity Information	US EPA, Air Risk Information Support Center. Health Effects Notebook for Hazardous Air Pollutants. http://www.epa.gov/ttnatw01/hlthef/hapindex.html
RTECS^®- TLV/BEI,2005	RTECS^®- TLV/BEI,2005
RTECS^®- TLV/BEI,2006	RTECS^®- TLV/BEI,2006
RTECS^®- TLV/BEI,2007	RTECS^®- TLV/BEI,2007
RTECS^®- Gigiena i Sanitariya 1972	RTECS^®- Gigiena i Sanitariya. For English translation, see HYSAAV. (V/O Mezhdunarodnaya Kniga, 113095 Moscow, USSR) V.1- 1936- 37(10),27,1972
RTECS^®- Journal of the National Cancer Institute 1955	RTECS^®- Journal of the National Cancer Institute. (Washington, DC) V.1-60, 1940-78. For publisher information, see JJIND8. 16,447,1955
RTECS^®- Toxicologist 2003	RTECS^®- Toxicologist. (Soc. of Toxicology, Inc., 475 Wolf Ledge Parkway, Akron, OH 44311) V.1- -1981 72,219,2003
RTECS^®- Toxicologist 2008	RTECS^®- Toxicologist. (Soc. of Toxicology, Inc., 475 Wolf Ledge Parkway, Akron, OH 44311) V.1- 1981- 12,430,2008
RTECS^®- Toxicologist 2003	RTECS^®- Toxicologist. (Soc. of Toxicology, Inc., 475 Wolf Ledge Parkway, Akron, OH 44311) V.1- 1981- 72,219,2003
RTECS^®- Zeitschrift fuer Krebsforschung 1942	RTECS^®- Zeitschrift fuer Krebsforschung. (Berlin, Fed. Rep. Ger.) V.1-75, 1903-71. For publisher information, see JCROD7. 52,425,1942

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