Assingment #1 - Attempt #2 - Team Beta

Hexavalent Chromium -
Chromium exists primarily in trivalent (Cr(III)) or hexavalent (Cr(VI)) oxidation states. Cr(VI) is a notorious environmental pollutant because it is a strong oxidant and much more toxic than Cr(III) and carcinogenic. Cr(VI) exists as the chromate ion in basic solutions and as dichromate in acidic solutions.[1]
One of the traditional methods for determining Cr(VI) uses diphenylcarbohydrazide (DPC) to form an intensely colored complex with Cr(VI). The complex is measured quantitatively by its visible absorption at 520 nm. However, as in any colorimetric analysis, this test is subject to positive interferences from other colored materials in the sample as well as from other elements that form colored complexes with DPC. [1]
Hexavalent chromium is used for the production of stainless steel, textile dyes, wood preservation, leather tanning, and as anti-corrosion and conversion coatings as well as a variety of niche uses. [2]
Hexavalent chromium is recognized as a human carcinogen via inhalation. [3] Workers in many different occupations are exposed to hexavalent chromium. Problematic exposure is known to occur among workers who handle chromate-containing products as well as those who arc weld stainless steel.[3] Within the European Union, the use of hexavalent chromium in electronic equipment is largely prohibited by the Restriction of Hazardous Substances Directive
Chemical name: Ammonium Dichromate Chromium[VI]

Synonyms: Chromic acid, diamonium salt

Chemical Formula: (NH4)2Cr2O7

CAS registry: 7789-09-05


Chromium VI New Field Detection Method for Ground Water Sampling -

Hexavalent chromium (Cr VI) is very toxic and a carcinogen compound found in groundwater all over. Testing for such a toxic has become increasingly important. Previously, field sampling for hexavalent chromium has been somewhat difficult. Several interested parties, including the USGS (United States Geological Survey) have been working on developing new field methods for collecting and analyzing ground water for the presence of chromium VI. The most popular method used since 2003, developed in part by USGS, enables the field distinguishment between Cr VI and its less toxic form, chromium III. The advantages of the new field method include lower detection limits, down to 0.05 micrograms per liter; small cation exchange cartridge that allows Cr VI to be stabilized in the field; storage of field samples for up to several weeks; as well as the use of common lab equipment to reduce analytical cost. Time stability of preserved samples is a great advantage over the 24 hour time constraint specified for EPA method 218.6. Prior to 2003, Cr VI field analysis was not very reliable and very expensive. The newer method is comparable with standard laboratory based methods. Since the toxicity of Cr VI is widely known, quicker more accurate field sampling is of great benefit to communities. (Ball, James. 2003. A New Cation-Exchange Method for Accurate Field Speciation of Hexavalent Chromium).

Health Effects –

“The respiratory tract is the major target organ for chromium (VI) toxicity, for acute (short-term) and chronic (long-term) inhalation exposures. Shortness of breath, coughing, and wheezing were reported from a case of acute exposure to chromium (VI), while perforations and ulcerations of the septum, bronchitis, decreased pulmonary function, pneumonia, and other respiratory effects have been noted from chronic exposure. Human studies have clearly established that inhaled chromium (VI) is a human carcinogen, resulting in an increased risk of lung cancer. Animal studies have shown chromium (VI) to cause lung tumors via inhalation exposure.“ (EPA, 2000)

Short term Effects of Cr VI
- Bronchial effects such as shortness of breath, coughing, wheezing
- Gastrointestinal and neurological effects
- Skin burns

Long Term Effects of Cr VI
- Perforations of the septum
- Bronchial effects such as bronchitis, decreased pulmonary functions, asthma and pneumonia
- Effects on the liver, kidney and immune system
- Upper respiratory tract, reproductive and renal effects

Other Effects of Cr VI
- Complications during pregnancy
- Complications during childbirth

Cancer Risks from Cr VI
- Classified as a human carcinogen



Case Study 1 -

A relatively recent industrial source of concern for CrVI is Portland Cement. Concrete, a very common building material is a mixture of portland cement, aggregate (sand and rock), and water. Raw materials used in the manufacture of portland cement, such as limestone, clay, and silica contain naturally occurring sources of chromium. During the cement manufacturing process, raw materials, are mixed and heated in a large kiln to produce an intermediate pebble-sized material called clinker. Fugitive dust emissions from stored piles of clinker are alleged to be a significant source of CrVI contamination to air, soil, and potentially groundwater in the area surrounding a cement plant operated by TXI International near Riverside, California. (Insurance Journal, 2008)

Cr VI Case Study 2 -

Erin Brockovich, who was depicted by Julia Roberts in a Hollywood motion picture, has played a large roll in the world of Hexavalent Chromium in drinking water. Her first major case was in Henkley, California where she won over 330 million dollars for a town whose drinking water was nearly 6 times the Maximum Contaminant Level (0.10 PPM) set by the EPA (Brockovich, Famous Trials, Chapter 1 Preface." Enemy at the Gates, Thirteen Days, Erin Brockovich, Stories Behind The Movies. 15 Sep. 2009 ).
Later, in 2007, at a site in Oinofyta, Greece, Brockovich became involved at a similar case involving the Asopos River (Brockovich, Erin. " Pollution Flows in Asopos :: The Brockovich Report ." The Brockovich Report :: Published by Los Angeles Area Consumer Advocate Erin Brockovich. 25 Aug. 2007. 15 Sep. 2009 )

Most recently Brockovich has been invovled in a major drinking water case in Midland, Texas where well water has been reported to have hexavalent chromium levels 10 times higher than those at the Henkley California site ("The Real News Network - Erin Brockovich Is Back." The Real News. 15 Sep. 2009 ).
Though Brockovich has a many opponents that say her work is a sham, I believe she has done great things to bring areas back into federal or local regulatory Cr VI levels. She has prospered greatly from her work but more so have so many others who had been, or could have been affected by the contamination.

Case Study 3 -

An example of an airborne Cr VI case study comes from Davenport California where a local Cemex cement plant was the source of levels of contamination above those set by local standards, however the recorded levels were below those set by the EPA. The significance of this case is that it bring to light Cr VI as a harmful by product possible in the production of cement (McCord, Shanna. "Chromium 6 testing continues in Davenport, Cemex changes business practices - October 9th,2008 by Shanna McCord." Home - Santa Cruz Sentinel. 9 Oct. 2008. 15 Sep. 2009 ).

The results of air sampling at the Cemex plant in Davenport had shown to be within regulatory limits by the 1st of the year, however, later in January 2009 the plant laid off most off it's 125 employees due to the recession ("Davenport's Cemex Plant Stops Production: More than 100 Employees Laid Off - KION - Monterey, Salinas, Santa Cruz - News Weather-." KION - Monterey, Salinas, Santa Cruz - News Weather- - Home. 19 Jan. 2009. 29 Sep. 2009 ).





References


"5. Potential for Human Exposure." Department of Health and Human Services. www.atsdr.cdc.gov/toxprofiles/tp7-c5.pdf (accessed September 15, 2009).

Agency for Toxic Substances and Disease Registry (ATSDR). 2008. Toxicological profile for Chromium (Draft for Public Comment). Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.

"Air Toxics Hotspots Program Risk Management Guidelines, Part II: Technical Support Document for Describing Available Cancer Potency Factors ." Office of Environmental Health Hazard Assessment. www.oehha.ca.gov/pdf/HSCA2.pdf (accessed September 15, 2009).

Australian Centre for International Agricultural Research (ACIAR) Media Release (2003). Cleaning Up Tannery Waste. Retrieved September 17, 2009 from the World Wide Web: http://www.aciar.gov.au/node/10365

Brockovich, Erin. " Pollution Flows in Asopos :: The Brockovich Report ." The Brockovich Report :: Published by Los Angeles Area Consumer Advocate Erin Brockovich. 25 Aug. 2007. 15 Sep. 2009

California AG sues cement plant for hexavalent chromium exposure. (2008). Retrieved September 18, 2009, from http://www.insurancejournal.com/news/west/2008/07/08/91677.htm

"Chromium Compounds | Technology Transfer Network Air Toxics Web site | US EPA." U.S. Environmental Protection Agency. http://www.epa.gov/ttn/atw/hlthef/chromium.html (accessed September 15, 2009).

Chromium (VI) (CASRN 18540-29-9) | IRIS | US EPA." U.S. Environmental Protection Agency. 22 Sep. 2009

"Davenport's Cemex Plant Stops Production: More than 100 Employees Laid Off - KION - Monterey, Salinas, Santa Cruz - News Weather-." KION - Monterey, Salinas, Santa Cruz - News Weather- - Home. 19 Jan. 2009. 29 Sep. 2009.

Gerd Anger, Jost Halstenberg, Klaus Hochgeschwender, Christoph Scherhag, Ulrich Korallus, Herbert Knopf, Peter Schmidt, Manfred Ohlinger, "Chromium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.

Gonzalez, Juan. "Indiana Guardsmen Sue KBR Over Chemical Exposure in Iraq." Democracy Now! | Radio and TV News. 4 Dec. 2008. 15 Sep. 2009

Hexavalent Chromium, Cr(VI), Analysis. (n.d.). Retrieved September 16, 2009, from http://www.wcaslab.com/tech/HEXCHROM

"Hexavalent chromium - Wikipedia, the free encyclopedia." Wikipedia, the free encyclopedia. 20 Sep. 2009

IARC (1999-11-05) [1990] (PDF). Volume 49: Chromium, Nickel, and Welding. Lyon: International Agency for Research on Cancer. ISBN 92-832-1249-5. http://monographs.iarc.fr/ENG/Monographs/vol49/volume49.pdf. Retrieved 2006-07-16.
Mandate, Congressional, the Agency for Toxic Substances, Toxicity, and Potential for Human Exposure. Toxicological profiles are developed from a priority list of 275 substances. ATSDR also prepares toxicological profiles for the Department of Defense (DOD). "ATSDR - Toxicological Profile Information Sheet." ATSDR Home. http://www.atsdr.cdc.gov/toxpro2.html#bookmarkset19 (accessed September 15, 2009).


"KBR - Featured Articles." KBR, Inc.: A Leading Global Engineering, Construction and Services Company.. 29 Sep. 2009. 29 Sep. 2009 .

McCord, Shanna. "Chromium 6 testing continues in Davenport, Cemex changes business practices - October 9th,2008 by Shanna McCord." Home - Santa Cruz Sentinel. 9 Oct. 2008. 15 Sep. 2009

Mineral tolerance of animals . washington: National Research Council Committee on Minerals and Toxic Substances. , 2005. Pg 116-120

NIOSH Topic: Hexavalent Chromium | CDC/NIOSH." Centers for Disease Control and Prevention. 18 Sep. 2009

Photo of concrete pouring retrieved 18 Sep 2009 from http://www.speciation.net/Public/News/2007/04/12/2796.html

Srinath, T., Verma, T., Ramteke, P.W., Garg, S.K. (2002). Chromium (VI) biosorption and bioaccumulation by chromate resistant bacteria Chemosphere, 48 427-435.

THE ASSOCIATED PRESS. "National Briefing - Northwest - Oregon - Possible Chemical Exposure - NYTimes.com." The New York Times - Breaking News, World News & Multimedia. 12 Feb. 2009. 15 Sep. 2009

"The Real News Network - Erin Brockovich Is Back." The Real News. 15 Sep. 2009

"There is sufficient evidence in humans for the carcinogenicity of chromium[VI] compounds as encountered in the chromate production, chromate pigment production and chromium plating industries."

Toxicological profile for chromium(2008). (ATSDR Toxicological Profile. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry. Retrieved from http://www.atsdr.cdc.gov/toxprofiles/tp7.html

U.S. Environmental Protection Agency. (2000). Chromium compounds hazard summary. Retrieved September 18, 2009, from http://www.epa.gov/ttn/atw/hlthef/chromium.html