### 



## General Populations

 The general population may be exposed

to chromium daily through food, drinking water, and air.



###  The predominant route of exposure for

the general population is ingestion of chromium in the diet

.



###  Exposure may also occur through

inhalation of contaminated air and consumption of contaminated water

.



###  Chromium(III) is an essential nutrient

required for normal energy metabolism.



###  The Institute of Medicine of the National

Academy of Sciences determined an adequate intake of chromium(III) of 20

– 45 μg/day for adolescents and adults.



## Occupational Populations

 Workers in approximately 80 industries

may be exposed to chromium(VI).



###  Occupational exposure to chromium

primarily occurs from chromate production, stainless s teel production and welding, chromium plating, ferrochrome alloys, and chrome pigment production

. Workers in the tanning industries are also potentially exposed to chromium. 

## Toxicokinetics

 The toxicokinetics of a given chromium

compound depend on the val ence state of the chromium atom and its solubility.



###  Chromium is absorbed through the

lungs; l ess

- water soluble compounds have a longer retention time in the lung than more soluble forms.



###  Less than 10% of an ingested chromium

dose is absorbed fr om the gas trointestinal

tract. More soluble compounds have higher absorption fractions

.



###  Chromium can penetrate human skin to

some extent, especially if the skin is damaged.



###  Absorbed chromium is distributed to

nearly all tissues, with the highest concentrations found in kidneys and liver. Bone is also a major depot and may contribute to long

- term retention.



###  Chromium(VI) is reduced to

chromium(III) via the intermediate forms of chromium(V) and chromium(IV).



###  Absorbed chromium is predominantly

excreted in the urin e.



## Normal Human Levels

 In the general population, the mean

levels of chromium in serum and urine

are 0.10

– 0.16 and 0. 22 μg/L, respectively. 

## Biomarkers

 Chromium (III) is an essential element

and is normally present in blood and urine.



###  Exposure to higher than normal levels of

chromium may result in increased chromium levels in blood, urine, expired air, hair, and nails.



###  Elevations in chromium in blood and

urine are considered the most reliable biomarkers of exposure.



## Environmental Levels

Air



###  Median concentration s in ambient air are

<20 ng/m 3

.



###  Indoor air in areas with cigarette smoking

can be 10 –4 00 times higher than outdoor air. Sediment and Soil



###  The mean concentration of chromium in

soil is 37.0 mg/kg.
Water



###  Most drinking water supplies in the

U nite d S tates contain <5 μg/L of chromium.



## Reference Agency for Toxic Substances and Disease Registry (ATSDR). 20 12 . Toxicological Profile for Chromium . At l anta, GA: U.S. Department of Health and Human Services, Public Health Services. 

# ToxGuide TM


# for 

# Ch romium

Cr

CAS# 7440

- 47 -3

October 2012



### U.S. Department of Health and Human Services Public Health Service Agency for Toxic Substances and Disease Registry www.atsdr.cdc.gov



### Contact Information: Division of Toxicology and Human Health Sciences Environme ntal Toxicology Branch

1600 Clifton Road NE, F

- 57 Atlanta, GA 30333 1-8 00

- CDC

- INFO

1-8 00

- 232

- 4636 http://www.atsdr.cdc.gov/toxprofiles/index.asp 

## Toxicokinetics and Normal Human Levels Biomarkers/ Environmental Levels Sources of Exposure The ToxGuide TM is developed to be used as a pocket guide. Tear off at perforation and fold along lines.

## Routes of Exposure Relevance to Public Health (Health Effects) Chemical and Physical Information

Chromium is a Metal

 Chromium is a naturally occurring

element found in roc ks , animals, plants, and soil, where it exists in combination with other elements to form various compounds.



###  The main forms of chromium are:

chromium(0), chromium(III), and chromium(VI).



###  Chromium is widely used in

manufacturing processes to make various

met al alloys such as stainless steel.



###  Chromium can be found in many

consumer products such as: wood treated with copper dichromate, leather tanned with chromic sulfate, stainless steel cookware, and metal

- on

- metal hip replacements. 

###  Inhalation – Predominant route of exposure for occupational populations.



###  Oral – Predominant route of exposure

for the general population.



###  Dermal – Minor route of exposure for

the general population.



## Chromium in the Envir onment

 Chromium is released into the

atmosphere via industrial, commercial, and residential fuel combustion of natural gas, oil, and coal and from emissions from metal industries such as chrome plating and steel production.



###  Approximately 1/3 of atmospher ic

releases are believed to be in the form of chromium(VI).



###  Electroplating, leather tanning, and textile

industries release large amounts of chromium to surface water.



###  Chromium is primarily removed from the

atmosphere by fallout and precipitation, the re sid ence time is expected to be <10 days.



###  Most of the chromium released in water

will be deposited in the sediments.



###  Chromium is not believed to biomagnify

in the food chain. 

## Minimal Risk Levels (MRLs)

Inhalation



###  No acute

- duration inhalatio n MRL s

(≤14 days) w ere derived for Cr ( III) or Cr (V I)

.



###  Intermediate

- duration inhalation MRLs

(15

– 364 days) were derived:

5x10 -6 mg Cr/m 3 for Cr(VI) aerosols and mists
3x10 -4 mg Cr/m 3 for Cr(VI) particulates
5x10 -3 mg Cr/m 3 for insoluble Cr(III) particulate s 1x10 -4 mg Cr/m 3 for soluble Cr(III) particulates



###  An MRL of 5x10 -6 mg Cr/m 3 has been

derived for chronic

- duration inhalation exposure to Cr (V I) aerosols and mists of ( ≥1 year ). Oral



###  No acute

- duration oral MRL (≤14 days)

was derived for Cr(VI)

.



###  An MRL of 5 x10 -3 mg Cr/kg/day has

been derived for intermediate

- duration oral exposure to Cr(VI) (15

– 364 days).



###  An MRL of 9x10 -4 mg Cr/kg/day has

been derived f or chronic

- duration oral exposure to Cr(VI) (≥1 year).



###  No acute

- , intermediate

- , or chronic

duration oral M RLs were derived for Cr (III)

. 

## Health effects are determ ined by the dose (how much), the duration (how long), and the route of exposure. Health Effects

 In general, chromium(VI) compounds

are more toxic than chromium(III) compounds.



###  The most sensitive targets of

chromium(VI) are the respiratory (nasal and lung irritation and altered pulmonary function following inhalation exposure), gastrointestinal (irritation, ulceration, and stomach and small intestine lesions following oral exposure), hematological (microcytic, hypochromic anemia), and reproductive (decreas ed sperm count and epididymal damage) systems

.



###  The primary targets of chromium(III)

compounds are the respiratory (following inhalation exposure) and immunological systems. Chromium allergic dermatitis is typically elicited by dermal contact in sensitized individuals.



###  DHHS, IARC, and EPA have classified

chromium(VI) as a human carcinogen.



###  IARC has classified chromium(III) and

metallic chromium as not classifiable as to their carcinogenicity to humans.



## Children’s Health

 It is unknown whether children are more

sensitive to chromium poisoning than adults.



###  In laboratory animals, chromium (VI)

causes miscarriages, low birth weight, and changes in development of skeleton and reproductive system. These developmental effects may be related, in part, to maternal chromium toxicity

.