Acrylonitrile health effects

Levels of Significant Exposure to Acrylonitrile - Inhalation 2-2 Levels of Significant Exposure to Acrylonitrile—Oral 2-3 Proposed Metabolic Scheme for Acrylonitrole 2-4 Existing Information on Health Effects of Acrylonitrile 5-1 Frequency of Sites with Acrylonitrile Contamination... 

Human Health Effects from Breathing Acrylonitrile ... 

Animal Health Effects from Eating or Drinking Acrylonitrile... 

This Statement was prepared to give you information about acrylonitrile and to emphasize the human health effects that may result from exposure to it. The Environmental Protection Agency (EPA) has identified 1,177 sites on its National Priorities List (NPL). Acrylonitrile has been found at 3 of these sites. However, we do not know how many of the 1,177 NPL sites have been evaluated for acrylonitrile. As EPA evaluates more sites, the number of sites at which acrylonitrile is found may change. The information is important for you to know because acrylonitrile may cause harmful health effects and because these sites are potential or actual sources of human exposure to acrylonitrile. 

If you are exposed to a hazardous substance such as acrylonitrile, several factors will determine whether harmful health effects will occur and what the type and severity of those health effects will be. These factors include the dose (how much), the duration (how long), the route or pathway by which you are exposed (breathing, eating, drinking, or skin contact), the other chemicals to which you are exposed, and your individual characteristics such as age, sex, nutritional status, family traits, life style, and state of health. 

Birth defects have been seen in animals exposed to high concentrations of acrylonitrile in the air or drinking water. Reproductive effects have been seen in animals given acrylonitrile in drinking water for three generations. However, no birth defects or effects on reproduction have been reported in humans. Further information on the health effects of acrylonitrile in humans and animals can be found Chapter 2. 

In humans, breathing acrylonitrile at a concentration of 16 parts of acrylonitrile per million parts of air (ppm) causes headaches, nausea, and disorientation (Table 1-1). This concentration is close to that at which acrylonitrile can be smelled in air (about 21 ppm). Breathing acrylonitrile in air for long periods of time and at high concentrations can cause death. The actual concentrations of acrylonitrile and breathing times which cause death have not been measured. There is no information on human health effects from eating or drinking acrylonitrile. Acrylonitrile can be smelled at a concentration of 19 ppm when dissolved in water. 

Tables 1-1 through 1-4 show the relationship between exposure to acrylonitrile and known health effects. Short-term and longer-term Minimal Risk Levels (MRLs) are also included in Tables 1-1 and 1- 3. These MRLs were derived from animal and human data for both short-term and long-term exposure, as described in Chapter 2 and in Tables 2-1 and 2-2. The MRLs provide a basis for comparison with levels that people might encounter either in the air or in food or drinking water. If a person is exposed to acrylonitrile at an amount below the MRL, it is not expected that harmful (noncancer) health effects will occur. Because these levels are based only on information currently available, some uncertainty is always associated with them. Also, because the method for deriving MRLs does not use any information about cancer, an MRL does not imply anything about the presence, absence, or level of risk for cancer.

There is a test that can detect acrylonitrile in blood. In addition, the major breakdown products of acrylonitrile by the body (termed metabolites) can be measured in urine. Some breakdown products that can be measured are specific to acrylonitrile. However, one breakdown product of the body (cyanide) that is commonly measured is not specific to acrylonitrile exposure, and the results can be affected by cigarette smoking. Because special equipment is needed, these tests cannot be performed routinely in your doctor s office. There is not enough information at present to use the results of such tests to predict the nature or severity of any health effects that may result from exposure to acrylonitrile. Further information on how acrylonitrile can be measured in exposed humans is presented in Chapters 2 and 6. 

The federal government has developed regulations and advisories to protect individuals from the potential health effects of acrylonitrile in the environment. The U.S. Environmental Protection Agency (EPA) recommends that acrylonitrile levels in water not exceed 0.058 ppb. Any release to the environment of more than 100 lb must be reported to the federal government. The Occupational Safety and Health Administration (OSHA) has established a legally enforceable maximum limit of 2 ppm in workplace air for an 8-hour exposure over a 40-hour work week. 

Table 2-1 and Figure 2-1 summarize quantitative data on the health effects observed in humans and laboratory animals exposed to acrylonitrile by inhalation. 

No studies were located regarding health effects in humans associated with the oral ingestion of acrylonitrile. Table 2-2 and Figure 2-2 summarize the health effects observed in experimental animals following oral exposure to acrylonitrile. These effects are discussed below. 

No studies were located regarding the following health effects in humans or animals after dermal exposure to acrylonitrile. 

Figure 2-4 summarizes areas concerning the health effects of acrylonitrile where studies have and have not been performed. There are some data available on the effects in humans following acute or chronic exposure to acrylonitrile via the inhalation route of exposure. The target organ for acute toxicity is the nervous system. Chronic exposure to acrylonitrile has been associated with cancer. However, many of the available reports lack quantitative information on exposure levels. In humans,... 

FIGURE 2-4. Existing Information on Health Effects of Acrylonitrile... 

Effects produced by exposure to acrylonitrile, particularly after acute exposures, are characteristic of cyanide toxicity. These effects can be detected in people exposed by evaluating signs and symptoms such as limb weakness, labored and irregular breathing, dizziness and impaired judgement, cyanosis and convulsions. While tests are not specific for acrylonitrile-induced toxicity, they do identify potential health impairment. Studies to develop more specific biomarkers of acrylonitrile-induced effects would be useful in assessing the potential health risk of acrylonitrile near hazardous waste sites. 

Section 104(i)(5) of CERCLA, directs the Administrator of ATSDR (in consultation with the Administrator of EPA and agencies and programs of the Public Health Service) to assess whether adequate information on the health effects of acrylonitrile is available. Where adequate information is not available, ATSDR, in conjunction with the NTP, is... 

Studies using radioactivity-labeled acrylonitrile indicate that acrylonitrile or its metabolites form covalent adducts with cellular macromolecules in most tissues. Studies to develop chemical or immunological methods for measuring these adducts would be especially valuable in detecting and perhaps even quantifying human exposure to acrylonitrile. Adverse health effects demonstrated following exposure to acrylonitrile, particularly acute exposures, were characteristic of cyanide toxicity. Because these effects are also indicative of exposure to many other toxicants, additional methods are needed for more specific biomarkers of effects of acrylonitrile exposure. 

Because of its potential to cause adverse health effects in exposed people, a number of regulations and guidelines have been established for acrylonitrile by various national and state agencies. These values are summarized in Table 7-1. 

EPA. 1987a. Health effects assessment for acrylonitrile. Cincinnati, OH U.S. Environmental... 

Sakurai H, Onodera M, Utsunomiya T, et al. 1978. Health effects of acrylonitrile in acrylic fibre factories. Br J Ind Med 35 219-225. 

Sakurai H (2000) Carcinogenicity and other health effects of acrylonitrile with reference to occupational exposure limit. Industrial Health 38(2) 165-180. 

Concerns about health effects caused by low levels of residual monomers in PVC and acrylonitrile resins promoted the consideration of condensation polymers such as poly(ethylene terephthalate) (PET) (41). Packaging resins based on acrylonitrile are extraordinarily good barriers that were considered for carbonated beverage bottles. The furor over residual monomers in these materials stunted their growth in spite of improved technology to reduce residuals to barely detectable levels. The step reaction polymer, polyethylene terephthalate(PET) has intrinsically much lower residual monomers in the as-made polymer, and it has become the material of choice for the carbonated beverage market (42). 

SAN resins themselves appear to pose few health problems in that they have been approved by the EDA for beverage botde use (149). The main concern is that of toxic residuals, eg, acrylonitrile, styrene, or other polymerization components such as emulsifiers, stabilizers, or solvents. Each component must be treated individually for toxic effects and safe exposure level. 

They also may not be directly adverse, but can indicate potential health impairment (e.g., DNA adducts). Biomarkers of effects caused by acrylonitrile are discussed in Section 2.5.2. 

Studies in animals indicate that acrylonitrile can produce teratogenic effects at doses that have little maternal toxicity, suggesting that pregnant women may also be susceptible. It also seems likely that individuals in poor health or with respiratory problems might be particularly susceptible to acrylonitrile, but there are no data on this point. 

Appel KE, Peter H, Bolt M, et al. 1981a. Effect of potential antidotes on the acute toxicity of acrylonitrile. Int Arch Occup Environ Health 49 157-163. 

EPA. 1985a. Health and environmental effects profile for acrylonitrile. Cincinnati, OH U.S. Environmental Protection Agency, Office of Research and Development. EPA/600/X-85/372. NTIS No. PB88-170832. 

Farooqui MYFI, Ahmed AE. 1983a. The effects of acrylonitrile on hemoglobin and red cell metabolism. J Toxicol Environ Health 12 695-707. 

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