Respirable particulate matter fraction

SOURCE APPORTIONMENT MODELS FOR THE ACETONE-SOLUBLE FRACTION OF RESPIRABLE PARTICULATE MATTER ... 

Silica sand is neutral and is compatible with all binders and normal cast alloys. The respirable particulate matter (RPM) fraction of quartz is classified by lARC as carcinogenic [233, lARC, 1997]. This is a health and safety issue. Studies are ongoing to determine whether or not an air pollution issue also exists. The amount of quartz in dust is defined by the content of quartz in the input materials. 

Because a filter sample includes particles both larger and smaller than those retained in the human respiratory system (see Chapter 7, Section III), other types of samplers are used which allow measurement of the size ranges of particles retained in the respiratory system. Some of these are called dichotomous samplers because they allow separate measurement of the respirable and nonrespirable fractions of the total. Size-selective samplers rely on impactors, miniature cyclones, and other means. The United States has selected the size fraction below an aerodynamic diameter of 10 /xm (PMiq) for compliance with the air quality standard for airborne particulate matter. 

Only 1.2% of the carbon of 2,4-D added to stream water was converted to organic particulate matter, the solids fraction in water containing the microbial cells. This lack of significant carbon assimilation may be a result of the inability of the microorganisms to obtain carbon and energy for biosynthetic purposes at these low concentrations, the immediate use of the carbon for respiration in order for the cells to maintain their viability (i. e., for maintenance energy), or the rapid decomposition and mineralization of the cells and their constituents. 

The 2003 ACGIH threshold limit valuetime-weighted average (TLV-TWA) for particulate matter containing no asbestos and <1% crystalline silica is 3mg/m for respirable size fraction and lOmg/m for inhalable mass fraction. Exposure to any substance in the particulate mass that has a designated TLV should be controlled to that value. 

The average ambient concentrations of the cyclohexane-, di-chloromethane- and acetone-soluble organic fractions from January, 1978 to August, 1979 were 2.9 yg/m, 1.0 yg/m and 4.4 yg/m. Respirable suspended particulate matter averaged 30.3 yg/m. ... 

Source Apportionment Models for the Cyclohexane-Soluble Fraction of Respirable Suspended Particulate Matter. Stepwise multiple regression analysis was used to determine the coefficients of the source tracers for the models proposed for CYC in equations (7)-(9). These models are shown in Table IV. As expected from the factor analyses, the coefficient for V, accounting for the greatest proportion of the variance of CYC, was fitted first into the equation. Equation (14) was the simplest and the F value was slightly higher than for equations (15) and (16). In addition, as will be discussed later in this paper, the coefficient for PB was in reasonable agreement with the ratio of CYC /PB for samples collected in the Allegheny Tunnel. 

Multivariate source. apportionment models have been developed for two fractions of respirable particulate organic matter which together constitute about 90% of the total organic solvent-extractable mass. The independent variables used for developing the models were trace metals, water-soluble sulfate and meteorological variables. Two of the three POM fractions extracted sequentially with cyclohexane (CYC), dlchloromethane (DCM) and acetone (ACE) were used as individual dependent variables. 

Due to polycyclic aromatic hydrocarbons are adsorbed to particulate matter and some of them are carcinogenous pollutans, the effect on heath depended of PAHs concentration and distribution in the different size particle, with special mention on respirable fraction with a diameter size less of 7 pm. 

A long time contact of the dissolved fraction with particulate matter can produce changes in the distribution of chemical forms of heavy metals in solution. Any change in the equilibrium conditions after collection can promote or remove dissolved metals (54) or desorption of adsorbed metals operated by particulate. Biological activity involves photosynthesis and respiration which will change the carbon dioxide content of the water and its pH. All the equilibrium reactions affected by pH will be altered, e.g., the reactions of precipitation, complexation and redox involving heavy metals. 

EXPOSURE GUIDELINES ACGIH TLV TWA 10 mg/m (for particulate matter containing no asbestos and <1% crystalline silica) OSHA PEL TWA 15 mg/m (total dust) 5 mg/m (respirable fraction) NIOSH REL TWA (no established REL) IDLH (not determined). 

Lipfert FW, Morris SC, Wyzga RE (2000) Daily mortality in the Philadelphia metropolitan area and size-classified particulate matter. J Air Waste Manag Assoc 50 1501-1513 McConnell R, Berhane K, Gilliland F et al (1999) Air pollution and bronchitic symptoms in Southern California children with asthma. Environ Health Perspect 107 757-760 McConnell R, Berhane K, Gilliland F et al (2003) Prospective study of air pollution and bronchitic symptoms in children with asthma. Am J Respir Crit Care Med 168 790-797 McDonnell WF, Nishino-Ishikawa N, Petersen FF et al (2000) Relationships of mortality with the fine and coarse fractions of long-term ambient PMio concentrations in nonsmokers. J Exposure Anal Environ Epidemiol 10 427-436... 

When low dispersible material is subjected to the high velocity impact test, particulate matter can be generated, but of aU airborne particulates up to 100 pm only a small (less than 10%) fraction will be expected to be in the respirable size range below 10 pm if the 100 limit is met. In other words, an equivalent quantity of low dispersible material less than 10 A2 could be released airborne in a respirable size range. It has been shown that for a reference distance of around 100 m and for a large fraction of atmospheric dispersion conditions this would lead to an effective dose below 50 mSv. 

During respiration, a fraction of inhaled aerosol particles deposits on the epithelium of the respiratory tract. While being retained, particles are subject to various interactions with the fluids, cells, and tissues of the respiratory tract. With use of a parameter to characterize the amount of particulate matter, such as mass m, number N, and such, a time-dependent function R ) describes the kinetics of particle retention. 

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