United States estimating exposure

Studies conducted in other industrialized countries have reported similar values to those obtained for the United States. Estimated daily intakes of CDDs and CDFs from various foods were calculated in a Canadian study of foods domestically produced in Canada or imported from the United States (Birmingham et al. 1989). Based on contamination levels (CDDs and CDFs) in samples of meats, eggs, lfuits, and vegetables from the United States and Canada, a total daily intake of 1.52 pg TEQs/kg body weight was calculated (for a 60-kg adult). The foods that contributed the most exposure to CDDs/CDFs TEQs were milk, eggs, and beef. Approximately one-half (0.81 pg TEQs/kg) was contributed by milk... 

Reviews on the occurrence, biochemical basis, and treatment of lead toxicity in children (11) and workers (3,12,13) have been pubhshed. Approximately 17% of all preschool children in the United States have blood lead levels >10 //g/dL. In inner city, low income minority children the prevalence of blood lead levels >10 //g/dL is 68%. It has been estimated that over two million American workers are at risk of exposure to lead as a result of their work. PubHc health surveillance data document that each year thousands of American workers occupationally exposed to lead develop signs and symptoms indicative of... 

Exposure. The exposure of humans and animals to mercury from the general environment occurs mainly by inhalation and ingestion of terrestrial and aquatic food chain items. Pish generally rank the highest (10—300 ng/g) in food chain concentrations of mercury. Swordfish and pike may frequently exceed 1 p.g/g (27). Most of the mercury in fish is methyl mercury [593-74-8]. Worldwide, the estimated average intake of total dietary mercury is 5—10 p-g/d in Europe, Russia, and Canada, 20 pg/d in the United States, and 40—80 pg/d in Japan (27). 

If possible comparisons are focused on energy systems, nuclear power safety is also estimated to be superior to all electricity generation methods except for natural gas (30). Figure 3 is a plot of that comparison in terms of estimated total deaths to workers and the pubHc and includes deaths associated with secondary processes in the entire fuel cycle. The poorer safety record of the alternatives to nuclear power can be attributed to fataUties in transportation, where comparatively enormous amounts of fossil fuel transport are involved. Continuous or daily refueling of fossil fuel plants is required as compared to refueling a nuclear plant from a few tmckloads only once over a period of one to two years. This disadvantage appHes to solar and wind as well because of the necessary assumption that their backup power in periods of no or Httie wind or sun is from fossil-fuel generation. Now death or serious injury has resulted from radiation exposure from commercial nuclear power plants in the United States (31). 

The Toxic Substances Control Act (TSCA) was enacted in 1976 to identify and control toxic chemical ha2ards to human health and the environment. One of the main provisions of TSCA was to estabUsh and maintain an inventory of all chemicals in commerce in the United States for the purpose of regulating any of the chemicals that might pose an unreasonable risk to human health or the environment. An initial inventory of chemicals was estabhshed by requiring companies to report to the United States Environmental Protection Agency (USEPA) all substances that were imported, manufactured, processed, distributed, or disposed of in the United States. Over 50,000 chemical substances were reported. PoUowing this initial inventory, introduction of all new chemical substances requires a Premanufacturing Notification (PMN) process. To be included in the PMN are the identity of the new chemical, the estimated first year and maximum production volume, manufacture and process information, a description of proposed use, potential release to the environment, possible human exposure to the new substance, and any health or environmental test data available at the time of submission. In the 10 years that TSCA has been in effect, the USEPA has received over 10,000 PMNs and up to 10% of the submissions each year are for dyes (382)... 

The National Occupational Exposure Survey (NOES), conducted by NIOSH from 1981 to 1983, estimated that 401,000 workers employed at 23,225 plant sites were potentially exposed to trichloroethylene in the United States (NOES 1990). The NOES database does not contain information on the frequency, concentration, or duration of exposures the survey provides only estimates of workers potentially exposed to chemicals in the workplace. 

Exposure to sexually transmitted diseases (STDs) is also a concern for women who are sexually active. It is estimated that 15 million people in the United States become newly infected annually with an STD.5 Given that not all methods of contraception protect the user adequately against STDs, the provision of proper patient education by health care professionals regarding this risk is absolutely essential. 

United States Environmental Protection Agency (2011) Estimation Programs Interface Suite for Microsoft Windows, http //www.epa.gov/oppt/exposure/pubs/episuite.htm. Accessed 09 Mar 2012... 

In the United States, the National Council on Radiological Protection and Measurements (NCRP) has recently issued two reports on this subject (NCRP, 1984a,b). The lifetime risks have been estimated and it is predicted that exposures of 2 WLM/y would reduce the probability of living to age 70 by 1.5 and an exposure level of 5 WLM/y would reduce that probability by 4 (NCRP, 1984a). For an average dose to the population of 0.2 WLM/y, the model predicts about 9000 deaths from lung cancer per year in the U.S. population (NCRP, 1984b) for nonsmokers. 

The presence of polycyclic aromatic hydrocarbons in the environment is of obvious concern and, apart from specific occupational environments, human exposure to these compounds derives from combustion products released into the atmosphere. Estimates of the total annual benzo[aJpyrene emissions in the United States range from 900 tons (19) to about 1300 tons (20). These totals are derived from heat and power generation (37-38%), open-refuse burning (42-46%), coke production (15-19%) and motor vehicle emissions (1-1.5%) (19,20). Since the vast majority of these emissions are from stationary sources, local levels of air pollution obviously vary. Benzo[aJpyrene levels of less than 1 pg/1,000 m correspond to clean air (20). At this level, it can be estimated that the average person would inhale about 0.02 pg of benzo[aJpyrene per day, and this could increase to 1.5 pg/day in polluted air (21). 

Endrin tends to persist in the environment mainly in forms sorbed to sediments and soil particles. A conservative estimate of its half-disappearance time in sandy loam soils is approximately 14 years (41% of endrin applied still remained in the soil after 14 years) (Nash and Woolson 1967). Therefore, the exposure risks from endrin to the general population of the United States are likely to steadily decrease over time. 

Exposure Levels in Humans. Metabolism of endrin in humans is relatively rapid compared with other organochlorine pesticides. Thus, levels in human blood and tissue may not be reliable estimates of exposure except after very high occupational exposures or acute poisonings (Runhaar et al. 1985). Endrin was not found in adipose tissue samples of the general U.S. population (Stanley 1986), or in adipose breast tissue from breast cancer patients in the United States (Djordjevic et al. 1994). Endrin has been detected in the milk of lactating women (Alawi et al. 1992 Bordet et al. 1993 Dewailly et al. 1993), but no data from the United States could be located. Data on the concentrations of endrin in breast milk from U.S. women would be useful. No information was found on levels of endrin, endrin aldehyde, or endrin ketone in blood and other tissues of people near hazardous waste sites. This information is necessary for assessing the need to conduct health studies on these populations. 

The primary route of exposure to thiocyanates for the general population appears to be from ingestion of foods in which thiocyanate occurs naturally (e.g., cabbage, kale, spinach, kohlrabi). Estimates of the thiocyanate concentration in the total diet of an adult in the United States were not located in the available literature however, these would be expected to be quite low. Exposure to cyanide also is a source of thiocyanate exposure because thiocyanate is a major metabolite of cyanide in the human body. 

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