Emission control lungs

From a public health point of view, the concentration of nickel associated with small particles that can be inhaled into the lungs is of greatest concern. The nickel content of aerosols from power plant emissions is not strongly correlated with particle size (Hansen and Fisher 1980). In one modem coal plant, 53% and 32% of nickel in emissions were associated with particles <3 and <1.5 pm in diameter, respectively (Sabbioni et al. 1984). Other studies found that only 17-22% of nickel emissions from coal-fired power plants were associated with particles of >2 pm, and that the mass medium diameter (MMD) of nickel-containing particles from a plant with pollution control devices was 5. 4 pm (Gladney et al. 1978 Lee et al. 1975). In one study, 40% of the nickel in coal fly ash was adsorbed on the surface of the particles rather than being embedded in the aluminosilicate matrix (Hansen and Fisher 1980). Surface-adsorbed nickel would be more available than embedded nickel. 

There have been limited field and controlled exposure studies that evaluated human reactions to carpet emissions. Winfield (1987) described a USA primary school where odor, headache, nausea, fatigue and mucosal irritation were reported by a high proportion of the students. Elevated indoor air concentrations of styrene (900-4000 xg m 3) were found, which were believed to be due to a SB R latex-backed carpet which had been installed several years previously. The carpet was removed and the ill-effects were reported to abate. Johnsen et al. (1990) exposed asthma sufferers to a foam rubber-backed carpet in a room chamber. While no clinical effects on lung function were observed, objective eye measurements found that there was a change in tear film quality. This was proposed to result from a degreasing effect of lipophilic VOCs, identified as toluene and acetone (Wolkoff, Nielsen and Hansen, 1990). 

Applications of catalytic combustion in primary pollution control mainly involve the control of NO.y emissions in natural gas-fueled gas turbines and boilers. NO,y emissions are atmospheric pollutants that cause serious pulmonary problems and are also precursors to the formation of ozone, another lung irritant. NOy emissions are therefore strictly regulated in many countries. Restrictions are especially severe in areas that have serious air quality problems, including California, Texas, the northeastern area of the United States, Japan and parts of Europe. 

---