Dear Dr. Sallam,

Chromium (VI) considered to be a most toxic metal/element if present in drinking water. In drinking water its concentration should be as low as 2 microgram/ litre but concentration as high as 120 microgram/ litre also reported. As per WHO guidelines the concentration of Cr in drinking water should not be exceeded from 0.05 mg/l or 50 microgram/ litre.

Atomic absorption spectrophotometer (AAS) or ICP MS/AES/OES can be used to determine the Cr content in water following acid digestion.

Please find attaching WHO guidelines for drinking water for other metals, inorganic & organic compounds/ pesticides etc in water.

Thanks.

Thanks Dr Kunal

But if the concentration is above 150 Micro/L in drinking water which will used for 3 months. what is the expected effects in the human health??

Dear Dr. Sallam,

Chromium toxicity can cause irritations and ulcers in respiratory tract and stomach. It may also cause blood anaemia, Sperm damage and damage to the male reproductive system, and known to be human carcinogens.

The following links may provide you much information regarding ill effects of Cr-6 present in drinking water on human health.

http://www.atsdr.cdc.gov/toxprofiles/tp7-c2.pdf

http://www.atsdr.cdc.gov/phs/phs.asp?id=60&tid=17

http://water.epa.gov/drink/contaminants/basicinformation/chromium.cfm

Thanks.

Dear Dr Kunal

is this effects Even if the use of water containing ratio of about 150 ms liter for three months only؟؟؟؟؟

Chromium tends to keep accumulating in the systems so even shorter but repeated exposures will lead to the consequences like ulcerations etc.

I am agree with Dr. Asef.

Not only chromium, every metal in the environment gets accumulated and its concentration is increasing with time until or unless its is (bio)degraded or (bio)accumulated. but for this the efficiency of degradation matters.

The accumulation of chromium leads to consequence of different ill effects as I describes earlier.

Prof Garg is overstating the toxicity of CrVI because he is referring to the California calculation described below. It is clearly incorrect. CrVI is rapidly converted to CrIII upon ingestion,. CrIII is probably an essential nutrient and also relatively insoluble. Some people take CrIII supplements because it might increase the rate of metabolism and therefore help weight loss. Maybe or maybe not.

The US EPA drinking water standard is currently 100 ug/L. The 2 ug/L number is an absurdly low value calculated by California OHEEA based upon assumptions without biochemical relevance on hypothetical low dose cancer risks in rats that were exposed at very high concentrations. The high dose tests obviously were at levels that exceeded the animal's natural reductive capacity in the GI tract, and the animal report postulated that it could explain the high dose carcinogenicity in the rat tests. Recent mechanistic studies have shown that an ingestion threshold must be exceeded before carcinogenicity can occur in the animals..

CrVI is a concern from inhalation where lung cancers have been observed in occupational exposures. Gastric cancers have not been observed from inhalation and human ingestion. Epidemiology studies do not support human cancer risks from ingestion of CrVI. The WHO value is 50 ppb for drinking water and it describes the high dose low dose chemistry. The irritation and ulcers are from high dose exposure not low dose exposure, such as occurs in drinking water.

Chromium is an element that occurs in nature in two oxidation states, 3 and 6 , in the oxidation state 3 has micronutrient activity therefore participating in the metabolism of fats as well as carbohydrates. However, in its oxidation state 6, has undesirable effects on living beings, has toxic effects in such diverse organ systems : renal damage, and liver cancer ; workers in tanneries damage occurs in skin and nasal septum , working with potassium chromate salts .

The potential effects of chromium on health depend on a variety of factors , such as the chemical form in which it is present, the amount , time of exposure and how the incorporation of chromium organism ( ingestion, inhalation or absorption through the skin). The reactions and their potential effects largely depend on such factors as the age, sex , body weight and health status of the individual. It is known that chromium 6 is carcinogenic by inhalation. The potential risks of chromium 6 in industrial activity have been widely documented. Many studies have shown higher rates of lung cancer in workers exposed to the inhalation of the same , and an increased rate of cancer of the gastrointestinal tract . Laboratory tests have also yielded strong evidence that chromium 6 can damage DNA and induce gene mutations.

The presence of chromium in drinking water is determined by atomic absorption spectroscopy , by graphite furnace technique . To discriminate chromium 3 and 6, can be performed by liquid chromatography high pressure .

Regards Isidoro Rubio Franchini

The enclosed occupational exposure meta analysis of CrVI indicates no cancer risks beyond lung cancers.

Cancer Epidemiol. 2010 Aug;34(4):388-99. doi: 10.1016/j.canep.2010.03.013. Epub 2010 Apr 28.

Occupational exposure to hexavalent chromium and cancers of the gastrointestinal tract: a meta-analysis.

Gatto NM1, Kelsh MA, Mai DH, Suh M, Proctor DM.

Author information

Abstract

INTRODUCTION:

We conducted a systematic literature review and meta-analysis of oral cavity, esophageal, stomach, small intestine, colon, and rectal cancers among workers occupationally exposed to Cr(VI).

METHODS:

Using PubMed, studies published from 1950 to 2009 evaluating the relationship between Cr(VI) exposure and GI cancers were identified. Measures of effect and variability were extracted from 32 studies meeting specific inclusion criteria, and meta-analysis summary relative risk measures were calculated using random effects models and inverse variance weighting methods.

RESULTS:

Meta-standardized mortality ratios (SMRs) were, for cancer of the: oral cavity [1.02 (95% CI=0.77-1.34)]; esophagus [1.17 (95% CI=0.90-1.51)]; stomach [1.09 (95% CI=0.93-1.28)]; colon [0.89 (95% CI=0.70-1.12)]; and rectum [1.17 (95% CI=0.98-1.39)]. Analyses of more highly exposed subgroups included in the studies or subgroups based on geographic region or by industry with recognized Cr(VI) exposures (welding, chrome plating, chromate production, and pigment production) did not result in elevated meta-SMRs except for esophageal cancer among US cohorts [meta-SMR=1.49 (95% CI=1.06-2.09)]. However, that finding was based on a subgroup of only four studies, one of which was a PMR study. Potential confounding by socioeconomic status (SES), diet and/or smoking, or limitations due to the healthy-worker effect (HWE) were evaluated, and while smoking, diet and SES may be important factors that may have upwardly biased the meta-SMRs, HWE is not likely to have significantly affected the summary results. None of three studies reporting small intestine cancers observed a statistically significant increased risk.

DISCUSSION:

These meta-analyses and literature review indicate that Cr(VI)-exposed workers are not at a greater risk of GI cancers than the general population.

Dr. Sallam,

see the websites below

http://water.epa.gov/drink/contaminants/basicinformation/upload/Chromium6inDrinkingWater.pdf

http://water.epa.gov/drink/contaminants/basicinformation/chromium.cfm

Thanks Dr Rebert

The EPA document is years out of date and should be ignored where it discusses cancer other than lung cancer from inhalation of CrVI. There is also a WHO IPCS document that was out of date when they published it.2 years ago. 14 mechanistic publications have appeared since then and EPA has not decided how to deal with them. EPA and California were very premature when they performed risk assessments by misinterpreting the NTP animal test data. As I said earlier, the more than 30 occupational epidemiology studies do not find cancers other than lung cancers related to inhalation. This became a hot issue because of the Erin Brokovitch movie from about 15 years ago. There has been long term followup by the State of California in that community and there is no indication of increased risks associated with chromium. In fact the cancer rates are actually somewhat less than predicted based upon the community population characteristics. The moral of the story is that poorly designed or poorly interpreted animal studies do not predict human risk, and movies are not a very good way to educate the public about toxicology.

I have recently published chapter on chromium that may be answer to your question

https://www.researchgate.net/publication/262063574_Trace_Metals__Chromium_Nickel_Copper_and_Aluminum

Regards Y .T.

Chapter Trace Metals – Chromium, Nickel, Copper, and Aluminum

The answer is: there are no health effects at the typical doses encountered in drinking water. You do not need to speciate unless the water is downstream from electroplaters or an uncontrolled discharger.. The standard AA procedure for total chromium is all you need.

@ Joseph A Cotruvo

Dear Dr Cotruvo,

Your perspective is quite interesting. I have to admit that geoscientists (like myself) always focus on the origin/pathway scenarios rather than the true health effects. These (health effects) are taken for granted, based on the variable references like those released form EPA or from local municipal agencies (I totally disagree with that). But maybe the truth is somehow different. Just to have some food for thought, you refer that “there are no health effects at the typical doses encountered in drinking water”. Can you quantify that threshold? Is all the CrVI metabolized to CrIII or there is an upper threshold beyond which CrVI remains without changing redox state?

Dear Mr Tziritis,

The NTP testing identified adverse effects only at the highest doses ~ 180 mg/L. . The reductive capacity of saliva and stomach fluid seems to be at  the multiple  milligrams level. The current US drinking water standard is 100 ppb.   Essentially all is rapidly converted to CrIII. However, mechanistically it is interesting that the nutritional  uptake of CrIII requires conversion to CrVI at the cellullar level. .

Please go through the following RG links and PDF attachment.

Article Groundwater Contaminated with Hexavalent Chromium [Cr (VI)]:...

Article Chromium pollution of soil and water in JinZhou

Chromium-6 is the Cancer causing Chemical ! Beware of it.

Thank you all dear respected scientists, as far as I know and working on metals , Chromium (VI) considered to be one of the most toxic metal/element if present in drinking water and its compounds cause mutations and allied effects such as chromosomal aberrations.

The carcinogenicity of chromium, especially with regard to lung tumours, has also been investigated in a number of inhalation studies; in other studies, the chromium was administered by implantation or injection. Based on all the available studies, it has been concluded that there is sufficient evidence in experimental animals for the carcinogenicity of calcium, lead, strontium, and zinc chromates (chromium(VI)); limited evidence for the carcinogenicity of chromium trioxide (chromic acid) and sodium dichromate; and inadequate evidence for the carcinogenicity of other chromium(VI) and chromium(IIII) compounds and of metallic chromium [ International Agency for Research on Cancer. Some metals and metallic compounds. Lyon, 1980:205-323 (IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans, Vol. 23). ; International Agency for Research on Cancer. Chromium, nickel and welding. Lyon, 1990 (IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 49). ].

Please try to determine of Cr(VI) in water samples by ICP-OES after separation of Cr(III).

kindly read the attached file, may be it be useful.

Even in small amounts, chromium-6 can cause skin burns, pneumonia, complications during childbirth and stomach cancer.

Dear Parisa, you are wrong about ingestion. Do not breath it, but ingesting some CrVI in drinking water at the WHO drinking water guideline of 50 ppb is NO risk, and maybe a little benefit. because it is likely an indirect nutrient. It rapidly converts to CrIII. The Mode of Action is understood and it does not occur near the Guideline with an ample margin of safety.

Studies are not required - think, Erin Brockovich. Search on the name and read the collection of ailments caused in that town.

State of California epidemiologists followed the town for many years and found no connections with CrVI. Actually, the cancer rates turned out to be somewhat lower than the demographic expectations. Be critical about what you find when you Google. Studies are much more reliable than anecdotal claims.

Thank you Joseph. Yes, there is material debate about the existence of clusters but the casual dismissal of those data is a cautionary flag. Certainly, I expect, we agree that the emotional baggage associated w such events, is not appropriate for even shallow scientific review. Those predispositions to a perspective are often hurricanes blowing in both directions, depending on when the questions are asked.

if your reading causes you to question the veracity of those data, then let’s agree to those data confirming that, to the degree we are capable of identifying and quantifying the linkage, aerosoled, hexavalent chromium is linked to lung cancer.

Chromium 6 is a carcinogenic metal.

Dependents which concentration range you are looking for, the best method will be ICP-MS which more than 1000 time-sensitive than ICP-OES for Cr VI and you do not need initial separation of Chromium III.

CrVI is carcinogenic by inhalation, but since it readily converts to CrIII when ingested it is only a concern if the dosage is so high that it overcomes the body's natural reductive capacity, which is quite high. Canada has reviewed the issue and concluded that it was THRESHOLD carcinogen when ingested, so its tox is treated by using safety factors. They arrived at 50 ppb with a substantial margin of safety. So, drinking water anywhere near the GV is NOT a cancer risk!

Well,

According to WHO,2011

In a long-term carcinogenicity study in rats given chromium(III) by the oral route, no increase in tumor incidence was observed. In rats, chromium(VI) is a carcinogen via the inhalation route, although an NTP study has shown evidence for carcinogenicity via the oral route at high doses. However, there is evidence that the dose-response relationship at low doses is non-linear because chromium(VI) is reduced to chromium(III) in the stomach and gastrointestinal tract. In epidemiological studies, an association has been found between exposure to chromium(VI) by the inhalation route and lung cancer. IARC has classified chromium(VI) in Group 1 (human carcinogen) and chromium(III) in Group 3 (not classifiable as to its carcinogenicity to humans). Chromium(VI) compounds are active in a wide range of in vitro and in vivo genotoxicity tests, whereas chromium(III) compounds are not.

Regards

Bayan,

You are Correct! Some other people learn science from Erin Brockovich movies and newspapers. Neither are very credible sources. They are produced by people who are trying to sell rather than educate.