Maximum permissible concentrations

The odor threshold for detection of ethyleneimine is 2 ppm. The maximum permissible concentration of ethyleneimine in the air at the place of work is 0.5 ppm (as specified in statutory regulations in the United States (374) and in Germany (375)). Animal experiments have shown ethyleneimine to be both carcinogenic (376) and mutagenic (377) (Table 2). 

Maximum Permissible Body Burdens and Maximum Permissible Concentration of Radionuclides in Air and in Water for Occupational Exposure, ReportNo. NCRP, No. 22, National Council on Radiation Protection and Measurement, Washington, D.C., 1959. 

The radiological hazard of tritium to operating personnel and the general population is controlled by limiting the rates of exposure and release of material. Maximum permissible concentrations (MPC) of radionucHdes were specified in 1959 by the International Commission on Radiological Protection (79). For purposes of control all tritium is assumed to be tritiated water, the most readily assimilated form. The MPC of tritium ia breathing air (continuous exposure for 40 h/wk) is specified as 185 kBq/mL (5 p.Ci/mL) and the MPC for tritium in drinking water is set at 3.7 GBq/mL (0.1 Ci/mL) (79). The maximum permitted body burden is 37 MBq (one millicurie). Whenever bioassay indicates this value has been exceeded, the individual is withdrawn from further work with tritium until the level of tritium is reduced. 

In the early development of such limits, they were generally known as Maximum Allowable Concentrations or MACs, sometimes called Maximum Acceptable Concentrations, or Maximum Permissible Concentrations. 

The WHO, the CEN, and the Environmental Protection Agency in the United States specify the maximum permissible concentrations of these metals and other pollutants in the environment. 

Maximum permissible concentration for exposure lasting 30-60 minutes... 

Ozone, O3, is the triatomic allotrope of oxygen. It is an unstable, blue diamagnetic gas with a characteristic pungent odour indeed, it was first detected by means of its smell, as reflected by its name (Greek o eiv, ozein, to smell) coined by C. F. Schonbein in 1840. Ozone can be detected by its smell in concentrations as low as 0.01 ppm the maximum permissible concentration for continuous exposure is 0.1 ppm but levels as high as 1 ppm are considered non-toxic if breathed for less than 10 min. 

In 1959 the International Commission on Radiological Protection (ICRP) recommended a "maximum permissible concentration of plutonium in water (MPCW) for unlimited public use" of 5x10 5 Ci/m3 ( xlO6 Bq/m3) (64). In 1979 ICRP introduced the concept of ALI ("annual limits of intake"). For 239Pu the value was set at 2xl06 Bq (or 0.9 mg) per year (35). Because man consumes about 0.5 m3 water/year, this ALI value corresponds to 4x106 Bq/m3 potable water. 

Waste water from a number of sources in mining and milling operations, which cannot be re-used, must be treated before discharge to the environment. Standards have been established for the maximum permissible concentrations of specific contaminants in the discharged water. 

All four wastewater treatment systems introduced in this chapter are technically feasible for treating nickel-chromium plating wastewater in order to meet the maximum permissible concentrations shown in Table 6.1 for industrial wastewater discharge into a municipal sewerage system15 or Table 6.2 for discharge to surface waters.21... 

Maximum Permissible Concentrations of Industrial Wastewater Discharge into Municipal Systems... 

Maximum Permissible Concentrations of Electroplating Wastewater Discharge to Surface Waters... 

MPC (maximum permissible concentration) — the highest concentration of a harmful substance in the environment (air, water, and soil), where this substance does not act unfavorably in the human body over an unlimited length of time. 

NCRP (1953). National Committee on Radiation Protection and Measurements, Maximum Permissible Amounts of Radioisotopes in the Human Body and Maximum Permissible Concentrations in Air and Water, NCRP Report No. 11, published as National Bureau of Standards Handbook No. 52, Superseded by NCRP Report No. 22 (National Council on Radiation Protection and Measurements, Washington). 

SC-34 Maximum Permissible Concentrations for Occupational and Non-Occu-pational Exposures... 

Land application of sludge and solid waste, maximum permissible concentration (mg Hg/kg waste) ... 

As informed Dr. A.I. Korableva from Institute for Environmental Management and Ecology under the National Academy of Sciences of Ukraine in the report "Environmental impact of automobile transport by example of Dnepropetrovsk", Dnepropetrovsk with its annual discharge of air pollutants of 177,000 t (as of 1996) is among the worst affected cities in Ukraine. In these, the automobile transport was found to be responsible for at least 30 % of the total emissions which are 15 times the maximum permissible level. Aside from the dust, chemical, photochemical and noise pollution, there is the aspect of street washout of automobile-related pollutants into the River Dnieper. The measured annual receipts of lead, particulates and petroleum derivatives via rainwater and thaw water to the river are 0.45, 80,000+ and 1.8+ t respectively. The actual levels of petroleum derivatives in storm water sometimes were 206 times the maximum permissible concentration (MPC) for the fishery basins. At 34 km downstream from the city, the estimated levels of petroleum derivatives and particulates are 61 and 10.8 times the respective MPCs. The airborne lead is mainly accumulated in the soil of housing areas. 

POCs proportions and content of POCs in river waters compared with maximum permissible concentration (MPC, for DDT, HCH and PCB, are equal to 100,20 and 1 ppb correspondingly for water and 100,100 and 100 for bottom sediments) behavior of toxic compounds in the water body factors promoting an increase of the ecological risk of polluted riverine input into the Caspian Sea (Figure 4). 

Table 1. Intervals of POP concentrations in modem background soils (mkg/kg) and their Maximum Permissible Concentrations (MPC) or Interim Acceptable Levels (IAL) in soil accepted in various countries.

The assessment of whether a substance presents a risk to the receiving environmental compartment is based on a comparison of the measured or predicted environmental concentration (PEC) of the chemical of concern with the predicted no effect concentration (PNEC) to organisms in the ecosystem. This is briefly discussed in Chapter 7.4. Studies carried out so far, e.g. by Vandepitte and Feijtel [91], show that the risk of anionic surfactants such as LAS, AE and AES for the aquatic environment is low, since the PECs are always lower than the maximum permissible concentrations. 

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