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National Drinking Water Database


National Drinking Water Database - Chemical Contaminants

Molybdenum


Status: Unregulated - EPA has not established a maximum legal limit in tapwater for this contaminant.

Molybdenum is a byproduct of copper and tungsten mining, and is used as an alloy for various metals; it also occurs naturally in soil and rock.

 
Detected
Found above
health guidelines
Found above
legal limit
States
9
4
-
Water utilities
299
21
-
People Served
25,141,504
158,331
-

Health Concerns for Molybdenum:


Molybdenum Exposure by State

Water utilities in 9 states have reported detecting Molybdenum in treated tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies.

StateWater Suppliers with Molybdenum contaminationWater suppliers reporting Molybdenum above health-based limits
SystemsPopulationSystemsPopulation
California3918,319,792192,115
Illinois2244,814,7161660,641
Ohio11126,45525,360
Vermont510,4302215
Nevada81,718,86100
Delaware1140,00000
New York69,58800
Minnesota41,46300
Alaska119900
Total29925,141,50421158,331

The Most Polluted Communities

299 water utilities reported detecting Molybdenum in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by highest average Molybdenum level

RankSystem Population Served Positive test results of total reported tests Average Level
(Range)
1Grandwood Park Subdivision
Libertyville, IL
5,6396 of 670.27 ppb
(59.5 to 82 ppb)
2Arden Shores Estates Subdivision
Libertyville, IL
661 of 160 ppb
(60 ppb)
3Fairfax Fire District 1
Fairfax, VT
801 of 160 ppb
(60 ppb)
4Hiatts Hideaway Mhp
East Peoria, IL
1502 of 352.67 ppb
(0 to 130 ppb)
5Ohio-American Water Co. - Lake Darby
Westerville, OH
4,4951 of 151 ppb
(51 ppb)
6Utl Inc-County Line Water Company
Northbrook, IL
3661 of 151 ppb
(51 ppb)
7Brookside Mhp
Starksboro, VT
1352 of 243 ppb
(36 to 50 ppb)
8East Alton
East Alton, IL
6,6951 of 141.2 ppb
(41.2 ppb)
9Ohio-American Water Co. - Timberbrook Pws
Westerville, OH
8651 of 141 ppb
(41 ppb)
10Milford
Milford, IL
1,3692 of 340.67 ppb
(0 to 95 ppb)

Health Based Limits for Molybdenum

StandardDescriptionLevel
Lifetime health-based limit, non-cancer riskConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for a lifetime of exposure. The Lifetime health-based limit (or Health Advisory, HA) is based on exposure for a a 70-kg adult consuming 2 liters of water per day. Source: U.S. Environmental Protection Agency.40 ppb
Health-Based Screening LevelA benchmark concentration of contaminants in water that may be of potential concern for human health, if exceeded. For noncarcinogens, the HBSL represents the contaminant concentration in drinking water that is not expected to cause any adverse effects over a lifetime of exposure. For carcinogens, the HBSL range represents the contaminant concentration in drinking water that corresponds to an excess estimated lifetime cancer risk of 1 chance in 1 million to 1 chance in 10 thousand. Source: U.S. Geological Survey.40 ppb
Children's health-based limit for 1-day exposureConcentration 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.80 ppb
Children's health-based limit for 10-day exposureConcentration 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.80 ppb
Drinking Water Equivalent LevelA 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.200 ppb

Testing Summary for Molybdenum

Are tests routinely required for Molybdenum by federal law?No
Water suppliers reporting tests for Molybdenum (2004-2009):1,161 of 47,576
Average testing rate for water supplier reporting tests (2004-2009):0.4 per year

Cancer

Type of concern: Reference:
Limited evidence of carcinogenicity Amer Conf of Gov't Industrial Hygienists - Carcinogens
One or more in vitro tests on mammalian cells show positive mutation results RTECS®- Gigiena Truda i Professional'nye Zabolevaniya 1980

Developmental/reproductive toxicity

Type of concern: Reference:
One or more animal studies show reproductive effects at low doses RTECS®- Gigiena i Sanitariya 1977
One or more animal studies show reproductive effects at low doses RTECS®- Farmakologiya i Toksikologiya (Moscow) 1978
One or more animal studies show reproductive effects at high doses RTECS®- Archives of Environmental Health 1971

Occupational hazards

Type of concern: Reference:
Allowed workplace exposures restricted to low doses RTECS®- TLV/BEI,2007
Allowed workplace exposures restricted to moderate doses RTECS®- TLV/BEI,2006
Allowed workplace exposures restricted to moderate doses RTECS®- TLV/BEI,2007
Single case study detailing occupational hazards Frazier , L, 1998

Organ system toxicity (non-reproductive)

Type of concern: Reference:
One or more animal studies show respiratory effects at low doses RTECS®- National Technical Information Service
One or more animal studies show liver effects at low doses RTECS®- "Vrednie chemichescie veshestva 1989
One or more animal studies show liver effects at moderate doses (low dose studies may be unavailable for this ingredient) RTECS®- "Vrednie chemichescie veshestva 1989
One or more animal studies show kidney or renal system effects at moderate doses (low dose studies may be unavailable for this ingredient) RTECS®- "Vrednie chemichescie veshestva 1989
One or more animal studies show metabolic effects at moderate doses (low dose studies may be unavailable for this ingredient) RTECS®- "Vrednie chemichescie veshestva 1989
Classified as not expected to be potentially toxic or harmful Environment Canada Domestic Substance List

Biochemical or cellular level changes

Type of concern: Reference:
One or more animal studies show biochemical changes at low doses where the human health implications are not yet well understood RTECS®- "Vrednie chemichescie veshestva 1989

Persistence and bioaccumulation

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

Enhanced skin absorption

Type of concern: Reference:
Suspected nano-scale ingredients with potential to absorb into the skin Nanomaterial Database

Ecotoxicology

Type of concern: Reference:
Not suspected to be an environmental toxin Environment Canada Domestic Substance List



Government, industry, academic studies and classifications

government/industry list/academic study appears on list as classification(s)
Amer Conf of Gov't Industrial Hygienists - CarcinogensMOLYBDENUM AS MO (SOLUBLE COMPOUNDS)•Confirmed animal carcinogen with unknown relevance to humans (ACGIH classification A3)
Association of Occupational and Environmental ClinicsMOLYBDENUM• o
Environment Canada Domestic Substance ListMOLYBDENUM•This chemical was NOT flagged by CEPA for further attention. The chemical was flagged for suspected persistence.
National Library of Medicine HazMapMOLYBDENUM AND COMPOUNDS•PEL (OSHA) - Permissible exposure limit (OSHA): 5 mg/m3, as Mo(sol. compds);
•TLV (ACGIH) - Threshold limit value (ACGIH): 10 mg/m3, as Mo, inhal. fraction, 3 mg/m3, as Mo, respir. fraction(metal and insol. compds), 0.5 mg/m3, as Mo, respir. fraction(sol. compds);
•IDLH (NIOSH) - Immediately Dangerous to Life or Health: 5000 mg/m3(metal), 1000 mg/m3, as Mo(sol. compds);
Nanomaterial DatabaseMOLYBDENUM•potential nano-scale ingredient
Frazier , L, 1998MOLYBDENUM•Reproductive toxicity hazards: suspected
RTECS®- TLV/BEI,2006MOLYBDENUM• occupationally related - ACGIH TLV (human TWA)
RTECS®- TLV/BEI,2007MOLYBDENUM• occupationally related - ACGIH TLV (human TWA)
RTECS®- "Vrednie chemichescie veshestva 1989MOLYBDENUM• metabolic - Weight loss or decreased weight gain (rabbit TDLo)
• liver - Other changes (rat TDLo)
• biochemical - Other oxidoreductases (rat TDLo)
RTECS®- Archives of Environmental Health 1971MOLYBDENUM• reproductive - Fetotoxicity (mouse TDLo)
RTECS®- Farmakologiya i Toksikologiya (Moscow) 1978MOLYBDENUM• reproductive - Musculoskeletal system (rat TDLo)
RTECS®- Gigiena i Sanitariya 1977MOLYBDENUM• reproductive - Musculoskeletal system (rat TDLo)
• reproductive - Post-implantation mortality (rat TDLo)
• reproductive - Pre-implantation mortality (rat TDLo)
RTECS®- Gigiena Truda i Professional'nye Zabolevaniya 1980MOLYBDENUM• mutagenic - Positive mutation assay: Cytogenetic Analysis (rat ihl)
RTECS®- Gigiena Truda i Professional'nye Zabolevaniya 1980MOLYBDENUM• mutagenic - Positive mutation assay: Cytogenetic Analysis (rat ihl)
RTECS®- National Technical Information Service MOLYBDENUM• respiratory - Fibrosis, focal (pneumoconiosis) (rabbit LDLo)



references

government/industry list/academic study reference
Amer Conf of Gov't Industrial Hygienists - CarcinogensACGIH (American Conference of Governmental Industrial Hygienists) 2008. ACGIH cancer classification system. www.acgih.org.
Association of Occupational and Environmental ClinicsAOEC (Association of Occupational and Environmental Clinics). 2009. AEOC exposures codes and asthmagen designation.
Environment Canada Domestic Substance ListEC (Environment Canada). 2008. Domestic Substances List Categorization. Canadian Environmental Protection Act (CEPA) Environmental Registry.
National Library of Medicine HazMapNLM (National Library of Medicine). 2006. HazMap — Occupational Exposure to Hazardous Agents.
Nanomaterial DatabaseNanoWerk. 2007. Nanomaterial Database. Available online: http://www.nanowerk.com/phpscripts/n_dbsearch.php
Scorecard.org Toxicity InformationFrazier , L. and M. L. Hage (eds.). Reproductive Hazards of the Workplace, Wiley Europe, 1998. Table 10 (Partial List of Reproductive Toxicants) available at http://www.pharmacy.ohio-state.edu/homepage/safety/chemhygiene_table_repro.pdf.
RTECS®- TLV/BEI,2006RTECS®- TLV/BEI,2006
RTECS®- TLV/BEI,2007RTECS®- TLV/BEI,2007
RTECS®- "Vrednie chemichescie veshestva 1989RTECS®- "Vrednie chemichescie veshestva. Neorganicheskie soedinenia elementov V-VII groopp" (Hazardous substances. Inornanic substances containing V-VII group elements), Bandman A.L. et al., Chimia, 1989. -,317,1989
RTECS®- Archives of Environmental Health 1971RTECS®- Archives of Environmental Health. (Heldref Pub., 4000 Albemarle St., NW, Washington, DC 20016) V.1- 1960- 23,102,1971
RTECS®- Farmakologiya i Toksikologiya (Moscow) 1978RTECS®- Farmakologiya i Toksikologiya (Moscow). For English translation, see PHTXA6 and RPTOAN. (V/O Mezhdunarodnaya Kniga, 113095 Moscow, USSR) V.2- 1939- 41,620,1978
RTECS®- Gigiena i Sanitariya 1977RTECS®- Gigiena i Sanitariya. For English translation, see HYSAAV. (V/O Mezhdunarodnaya Kniga, 113095 Moscow, USSR) V.1- 1936- 42(8),30,1977
RTECS®- Gigiena Truda i Professional'nye Zabolevaniya 1980RTECS®- Gigiena Truda i Professional'nye Zabolevaniya. Labor Hygiene and Occupational Diseases. (V/O Mezhdunarodnaya Kniga, 113095 Moscow, USSR) V.1-36, 1957-1992. For publisher information, see MTPEEI 24(9),33,1980
RTECS®- Gigiena Truda i Professional'nye Zabolevaniya 1980RTECS®- Gigiena Truda i Professional'nye Zabolevaniya. Labor Hygiene and Occupational Diseases. (V/O Mezhdunarodnaya Kniga, 113095 Moscow, USSR) V.1-36, 1957-1992. For publisher information, see MTPEEI 24(9),33,1980
RTECS®- National Technical Information Service RTECS®- National Technical Information Service. (Springfield, VA 22161) Formerly U.S. Clearinghouse for Scientific & Technical Information. PB249-458

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