Pollutants specific

Table 5.24 shows that these specific pollutants are present only in small proportions (about 8%) of the total organic compounds emitted by the motor, but they are particularly feared because of their incontestable toxicity. Prominent among them is benzene. 

Water Quality Standards. Water quaUty standards are usually based on one of two primary criteria, stream standards or effluent standards. Stream standards are based on dilution requirements for the receiving water quaUty based on a threshold value of specific pollutants or a beneficial use of the water. Effluent standards are based on the concentration of pollutants that can be discharged or on the degree of treatment required. 

In addition to using annuahzed cost comparisons in evaluating an air-poUution-control (APC) equipment installation, the impact of the 1990 Clean Air Act Amendments (CAAA) and resulting regulations also must be included in the evaluation. The CAAA prescribes specific pollution-control requirements for particular industries and locations. As an example, the CAAA requires that any major stationary source or... 

The effects attributed to air pollutants range from mild eye irritation to mortality. In most cases, the effect is to aggravate preexisting diseases or to degrade the health status, making persons more susceptible to infection or development of a chronic respiratory disease. Some of the effects associated with specific pollutants are listed in Table 7-2. Further information is available in the U.S. Environmental Protection Agency criteria documents summarized in Chapter 22. 

The U.S. Environmental Protection Agency has established National Ambient Air Quality Standards (NAAQS) for protection of human health and welfare. These standards are defined in terms of concentration and hme span for a specific pollutant for example, the NAAQS for carbon monoxide is 9 ppmV for 8 hr, not to be exceeded more than once per year. For a state or local government to establish compliance with a National Ambient Air Quality Standard, measurements of the actual air quality must be made. To obtain these measurements, state and local governments have established stationary monitoring networks with instrumentation complying with federal specifications, as discussed in Chapter 14. The results of these measurements determine whether a given location is violating the air quality standard. 

Air quality criteria are cause-effect relationships, observed experimentally, epidemiologically, or in the field, of exposure fo various ambient levels of specific pollutants. The relationships between adverse responses to air pollution and the air quality levels at which they occur have been discussed in Chapter 4 and illustrated in Table 4-5 and Fig. 4-10. 

Some variants of best practicable means are spelled out in the U.S. Clean Air Act of 1977. One is the requirement that best available control technology (BACT) for a specific pollutant be employed on new "major sources" that are to be located in an area that has attained the National Ambient Air Quality Standard (NAAQS) for that pollutant. BACT is also required for pollutants for which there is no NAAQS [e.g., total reduced sulfur (TRS), for which emission limits are specified by a Federal New Source Performance Standard (NSPS)]. BACT must be at least as stringent as NSPS but is determined on a case-by-case basis. 

Another variant is the lowest achievable emission rate (LAER) for a specific pollutant required for a new source of that pollutant to be located in a nonattainment area (i.e., one which has not attained the NAAQS for that pollutant), LAER is the lowest emission rate allowed or achieved anywhere without regard to cost or energy usage. LAER is intended to be more stringent than BACT or NSPS and is also determined on a case-bycase basis. 

When owners wish to build a new source which will add a specific amount of a specific pollutant to an area that is innonattainment with respect to that pollutant, they must, under U.S. federal regulations, document a reduction of at least that amount of the pollutant from another source in the area. They can effect this reduction, or "offset," as it is called, in another plant they own in the area or can shut down that plant. However, if they do not own another such plant or do not wish to shut down or effect such reduction in a plant they own, they can seek the required reduction or offset from another owner. Thus, such offsets are marketable credits that can be bought, sold, traded, or stockpiled ("banked") as long as the state or local regulatory agency legitimizes, records, and certificates these transactions. The new source will still have to meet NSPS, BACT or MACT, and/or LAER standards, whichever are applicable. 

Specific reduction targets for the different processes are not well established. In the absence of specific pollution reduction targets, new plants should always achieve better than the industry averages and should approach the load-based effluent levels. 

Indoor air often contains a variety of contaminants at concentrations that are far below any standards or guidelines for occupational exposure. Given our present knowledge, it is difficult to relate complaints of specific health effects to exposures to specific pollutant concentrations, especially since the significant exposures may be to low levels of pollutant mixtures. 

Attainment Area a geographic area in which levels of a criterion air pollutant meet the health-based National Ambient Air Quality Standard for that specific pollutant. 

PSD Increments the maximum increase in ambient pollution concentrations allowed over baseline concentrations. See 40 CFR 51.166 (c) for increments for specific pollutants. 

Application of contaminant removal effectiveness indices is relatively simple for scenarios with one or a few dominant contaminants being released. That is often the case in industrial mails. Where there are many polluting substances to consider the contaminant removal efficiency should ideally be evaluated for each one. Consequently, applications for regular indoor climate— for example, in a restaurant—are limited, except when addressing specific pollutants like smoking and ctxrking hunes. 

As discussed earlier, selectivity is the consequence of the interplay between toxicokinetic and toxicodynamic factors. Some examples are given in Table 2.8, which will now be briefly discussed (data from Walker and Oesch 1983, and Walker 1994a,b). These and other examples will be described in more detail under specific pollutants later in the text. In the table, comparisons are made between the median lethal doses or concentrations for different species or strains. Comparisons are made of data obtained in lethal toxicity tests where the same route of administration was used for species or strains that are compared. The degree of selectivity is expressed... 

US Congress amended the Federal Clean Air Act in 1990 to address a large number of air pollutants that are known to cause or may reasonably be anticipated to cause adverse effects to human health or adverse environmental effects. 188 specific pollutants and chemical groups were initially identified as hazardous air pollutants (HAPs), and the list has been modified over time. 

A lot of substances and components are present in wastewaters and can be measured, especially the emerging pollutants. However, in practice, the aggregate parameters (BOD, COD, TSS,...) and the physico-chemical ones (temperature, pH, dissolved oxygen, conductivity, turbidity,...) are more often monitored. The only specific compounds generally considered are the N and P forms, and in case of industrial wastewaters, some specific pollutants such as organics (phenolics, hydrocarbons,...) or metallic compounds. 

All of the reactions above (b - e) illustrate how microorganisms on solid phases mediate reactions that can cause or negate pollution. For example, nitrification (reactions b-c) and sulfur oxidation (reactions d-e) can result in the production of specific pollutants, i.e., nitrate and sulfuric acid... 

Emission standard the maximum amount of a specific pollutant permitted to be discharged from a particular source in a given environment. 

Pollution of soils and waters by human activities is an important and widespread problem. This pollution by, organic and inorganic substances can affect individual organisms, human populations, and ecosystems, each in its own unique way. In particular former military installations, often used for weapons production and nuclear power plants represent a ongoing and substantial threat to environment and human health because of the specific pollutants that can be released Solvents, explosives, fuels, radionuclides, heavy metals, and metalloids all have been identified in the environment around these installations. Remediation technologies for these contaminated sites have been developed based on conventional systems utilising physical and chemical treatments, such as excavation and incineration, pump-and-treat methods, ultraviolet oxidation, soil washing, etc. 

Because biomagnification and other transport processes take time, the harmful effect of many compoimds may not become evident for decades. This makes direct causal relationships between specific pollutants and environmental change difficult to establish. Substantiating such relationships is further complicated by the complex network of positive and negative feedbacks that occur among most parts of the crustal-ocean-atmosphere fectory. 

Andersen et a/.," with a saccharine-particle method, found a weak positive association between tracheobronchial clearance and nasal clearance. A strong positive correlation would have indicated that information about the tracheobronchial clearance rate can be derived by studying clearance rates in the nose, which is more accessible. The saccharine method was shown to be a useful clinical tool for evaluating the status of the nasal mucociliary function in human subjects exposed to ambient pollutants or to controlled concentrations of specific pollutant gases or aerosols. 

Before we can predict the response of a plant variety to a specific pollutant or group of pollutants, we must understand the following factors genetic variability (both between and within species), climatic and edaphic factors, interactions with other pollutants, interactions with biotic pathogens and insects, and the growth and physiologic age of susceptible plant tissue. The overall conceptualization of relationships between pollutant exposure and ultimate effects is shown simplistically (Figure 11-1) in an adaptation from van Haut and Stratmann. ... 

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