Particulate respirable

Air Pollution. Particulates and sulfur dioxide emissions from commercial oil shale operations would require proper control technology. Compliance monitoring carried out at the Unocal Parachute Creek Project for respirable particulates, oxides of nitrogen, and sulfur dioxide from 1986 to 1990 indicate a +99% reduction in sulfur emissions at the retort and shale oil upgrading faciUties. No violations for unauthorized air emissions were issued by the U.S. Environmental Protection Agency during this time (62). 

Black smoke (BS) is a particulate measure that typically contains at least 50% respirable particulates smaller than 4.5 mm in aerodynamic diameter, sampled by the British smokeshade (BS) method. The reflectance of light is measured by the darkness of the stain caused by particulates on a white filter paper. The result of BS sampling depends on the density of the stain and the optical properties of the particulates. Because the method is based on reflectance from elemental carbon, its use is recommended in areas where coal smoke from domestic fires is the dominant component of ambient particulates. 

Respirable particulates Particulates in the size range that can pass through the defence mechanisms in the human body and enter the lungs during inhalation. 

The 2003 ACGIH threshold limit valuetime-weighted average (TLV-TWA) for bituminous or lignite coal dust is 0.9mg/m as respirable particulate a TLV-TWA of... 

A historical data base of size-resolved particulate data suitable for source apportionment studies provides a wealth of data useful to regulatory authorities. As new programs begin to focus on Inhalable and respirable particulate standards, this data will become increasingly valuable. 

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

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. 

Vega, E., I. Garcia, D. Apam, M. E. Ruiz, and M. Barbiaux, Application of a Chemical Mass Balance Receptor Model to Respirable Particulate Matter in Mexico City, J. Air Waste Manage. Assoc., 47, 524-529 (1997). 

Fitz, D. R., G. J. Doyle, and J. N. Pitts, Jr., An Ultra-High Volume Sampler for the Multiple Filter Collection of Respirable Particulate Matter, J. Air Pollut. Control Assoc., 33, 877-879 (1983). 

Elutriator A device used to separate respirable and non-respirable particulates such as the cyclone or horizontal types. 

Scheff P, Valiozis C (1990) Characterization and source identification of respirable particulate matter in Athens, Greece. Atmos Environ 24 203-211... 

Dockery DW, Spengler JD (1981) Personal exposure to respirable particulates and sulfates. J Air Pollut Control Assoc 31 153-159... 

Most regulatory jurisdictions assume complete retention and absorption of inspirable and respirable particulates and gases. In a route-specific risk assessment... 

The metallic element whose concentration in air is most clearly ascribable to man s activities is lead. The level of lead found varies from about 0.1 iig/vn in sparsely populated areas to about 10 /xg/m in areas where automobile traflBc is at a maximum. In a study conducted at Los Angeles, two sites were monitored on either side of a freeway which had approximately 200,000 cars per day as a traflBc level 21), One site was downind a preponderance of the time. If the concentrations at the downwind site are divided by the concentrations of the site that was usually upwind, one can see, in Table XII, ratios that vary from 1.03 (where the percentage of favorable wind was 28) to 4.3 (where the favorable wind percentage was 68). In Table XIII are shown the results obtained when a massive respirable particulate sampler was field tested. The collector was built for EPA by Battelle Columbus. Particles greater than 20 /xm are eliminated with a cyclone. The first stage collects particles by impaction... 

Respirable particulate or gaseous forms of lead may be inhaled. Sources include cigarette smoke vehicle exhaust emissions from municipal waste incinerators, iron and steel plants, smelting and refining operations, lead acid battery manufacturing facilities, and sandblasting and burning of surfaces coated with lead paint. Particulate air emissions may eventually deposit and contaminate the soil. 

Particulates are another source of respiratory irritation when inhaled. In urban environments, diesel exhaust particles and fly ash residue from power plant oil combustion are the main contributors of respirable particulates of less than 10 pm diameter (PM 10). These contain mixtures of lipo-philes and hydrophiles including various metals, acid salts, aliphatic hydrocarbons, PAHs, quinones, nitroaromatic hydrocarbons, andaldehydes. 151 Diesel combustion particulates contain large surface areas that can adsorb large quantities of organic compounds and deliver these to respiratory tract tissue. Other inhaled particulates can adhere to lung surfaces and adsorb and bond other vapors that are inhaled, thereby increasing their toxicities. PM2.5 particulates (those with diameters of less than 2.5 pm) that reach the lower respiratory tract as far as the alveoli are more toxic than PM 10 particulates of the same composition. 16 ... 

Fig. 2 Exposures to respirable particulates in rural households of Kenya. Source Ezzati et al. [22]. The difference between male and female values is significant with P<0.0001...

Fig. 3 Distributions of concentrations and exposures to respirable particulates from bio-...

Gupta P, Banerjee DK, Bhargava SK, et al. 1993. Prevalence of impared lung function in rubber manufacturing factory workers exposed to benzo(a)pyrene and respirable particulate matter. Indoor Environ 2 26-31. 

The emissions of importance from burning include respirable particulates from the smoke plume, PAHs on particulate matter, and soot. 

Because TCDO has a very low volatility, TCDD uptake via inhalation is directly related to the concentration of airborne dust due to wind-blown soil. It has been estimated that of all airborne, respirable particulates, only about 30-50% comes from soil, while the rest is apparently due to products of combustion, tire wear and other sources (32). Of the total suspended particulates, usually no more than 50% are respirable (i.e., particles less than 10 urn). Of these, about 50% of the respirable particles are deposited in the upper airways and ultimately swallowed while the rest reach the alveoli or are expired. An analysis of CDC s data indicates that CDC assumed that 100% of the TCDD present on all the inhaled particles would be retained and absorbed in the respiratory tract. In contrast, the EPA assessment (2) assumed that only 25% of the inhaled particles would be absorbed in the lower airways since at least 50% of the particles would be non-respirable (especially by weight) and these will be swallowed due to impaction in the throat and only about 50% of the respirable particles would be absorbed. In any assessment, it is important to recognize that of those particles swallowed, no more than 10-30% should be absorbed since they will pass through the G.I. tract (assuming 10-30% oral bioavailability). 

---