How does mtbe affect humans

Studies in animals also failed to demonstrate skin sensitising potential on the part of MTBE, adding weight to the conclusion that MTBE is not a skin sensitiser. Observations suggesting transient CNS depression were consistently made also in animal studies using repeated inhalation and oral exposure. However, all effects were consistently made also in animal studies using repeated inhalation and oral exposure. However, all effects were reversed when exposure ended and repeated exposure did not lead to NOAELs that were lower than for single exposure.

Principle effects observed following repeat oral and inhalation exposure of rats and mice to MTBE are local irritation, transient anaesthetic effects as observed with many other low molecular weight ethers , chronic nephropathy and hepatocellular hypertrophy. MTBE has been tested extensively in vitro and in vivo for its genotoxic potential.

The weight of evidence shows MTBE is not genotoxic. The conclusion is supported by the information for TBA, which is not genotoxic in several in vitro and in vivo tests, and formaldehyde, which though genotoxic in a number of tests, is rapidly detoxified by the body thereby removing the potential to damage the cell.

An apparent increase in the incidence of Leydig cell tumours in male rats treated via inhalation was not considered to be relevant to humans. A non-genotoxic mechanism is likely to be involved. Further mechanistic studies are currently underway to clarify the mechanisms for the induction of these tumours.

The Task Force considered the rat Leydig cell tumour findings as not predictive of hazard to humans. Overall, the Task Force concluded that the doses necessary to evoke neoplastic effects are equal to or greater than the doses that induce non-neoplastic effects in female mouse liver and male rat carcinogenic effect.

Effects of MTBE vapour on reproduction and development have been evaluated in well-conducted inhalation studies with rats, mice and rabbits. Nevertheless, California , New Hampshire , New York , and other states have proposed or adopted conservative health-based primary drinking water standards of their own for MTBE.

EPA R, 59 pp, Describes the results of a study to estimate the relative contribution of the inhalation and dermal pathways during normal baths in water containing MTBE. Contact: Patty Toccalino, toccalino ese. International Journal of Occupational and Environmental Health 18 1 This paper briefly summarizes new findings and puts into perspective the totality of carcinogenic effects and environmental health risks on MTBE.

Congressional Research Service Reports: Paper 26, 29 pp, EPA R, pp, The site supports simultaneous searching in multiple databases. Breathing MTBE at high levels can cause animals to act as if they are drunk. For example, some became less active, staggered, fell down, were unable to get up, and had partially closed eyelids. These effects lasted only for about an hour, and then the animals seemed normal again. Some animals that breathed high levels of MTBE for several hours a day for several weeks gained less weight than normal, probably because they ate less food while they were inactive.

When rats breathed high levels of MTBE for several hours every day for two years, some got more serious kidney disease than these rats usually get as they grow old. Some of the male rats developed cancer in the kidney, but whether this has meaning for people is not known.

When mice breathed high levels of MTBE for several hours every day for a year and a half, some had larger livers than normal, and some mice developed tumors in the liver.

When rats were given high levels of MTBE by mouth for 2 years, some male rats developed cancer in the testes and some female rats developed cancer of the blood leukemia and cancer lymphoma of some of the tissues that produce blood cells. When pregnant rats, rabbits, or mice breathed MTBE, birth defects occurred only in the baby mice. We do not know if this has any relevance for people. MTBE did not affect the animals' ability to reproduce.

Some rats and mice died after being given very large amounts of MTBE by mouth. The amounts were much higher than people are likely to swallow from drinking water containing MTBE. Some animals that were given MTBE by mouth had diarrhea and irritation in their stomachs and intestines.

Some animals also had very slight liver damage. MTBE irritated the skin of animals when it was placed directly on their skin. MTBE also irritated the eyes of animals when it was placed in their eyes or when air containing MTBE came into contact with their eyes. There are no specific medical tests to determine whether you have been exposed to MTBE. But MTBE and its breakdown product, butyl alcohol, can be measured in exhaled air, in blood, and in urine.

Because MTBE and its breakdown products leave the body in 1 or 2 days, these measurements can only tell if you have been exposed recently. The effects of exposure to MTBE, such as stomach aches, fatigue, and dizziness, are common to many chemicals and illnesses. These symptoms are not very useful in determining whether you were exposed to this particular chemical. To protect workers, the American Conference of Governmental Industrial Hygienists ACGIH recommends that the amount in workroom air be limited to parts per million ppm in an 8- to hour work shift.

Toxicological profile for methyl t-butyl ether. Atlanta, GA: U. If you have questions or concerns, please contact your community or state health or environmental quality department or:. ATSDR can also tell you the location of occupational and environmental health clinics.

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