Organic lead in air

This may take two forms. The major part consists of vapour phase tetraalkyllead compounds which may be separated from inorganic lead by filtration of an air sample. A small portion of the organic lead exists in association with atmospheric particles, and probably takes the form of tetraalkyllead or trialkyllead salts adsorbed upon particulate air pollutants. 

The scientific literature has shown a wide variety of concentrations for tetraalkyllead vapour in air. These are best considered as a percentage of total lead in air, since this allows comparison of data from different sites without the need to correct for the effect of topography and meteorological conditions at the time of sampling. Even these percentages vary widely, but Harrison and Perry [16] have argued that many of the disparities have arisen from the use of non-specific analytical techniques. Values appear far more consistent if 

Downtown University area Residential Suburban commercial Rural 

The second form of organic lead in air is that associated with atmospheric particles. At an urban site in England, Harrison and Laxen found that this accounted for 0.2-1.2% of the total particulate lead [18]. At that site the mean atmospheric concentration of particle-associated organic lead (0.015 jug was rather less than 10% of total organic lead in air, the mean tetraalkyllead vapour concentration being measured as 0.16 Mg [19]. 

It might be anticipated that pollution transported from urban areas would be the major source of organic lead in rural air, since it is the major source of inorganic lead. This being the case, since the sinks for both inorganic and organic lead in air operate rather slowly, similar ratios of tetraalkyllead vapour to total lead might be expected in rural air as are observed in urban air. 

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Snyder, L. J. Determination of trace amounts of organic lead in air. Composite sample method. Anal. Ghem. 39, 591 (1967). 

Snyder, L. J., Determination of Trace Amounts of Organic Lead in Air, Composite Sample Method, Anal. Chem. 39 [1967] 591/5. 

The formation of carboxylic acids in these reactions may be a significant source of organic acids in air. Reaction (48a) appears to occur by at least two mechanisms. Thus, the addition of isotopically labeled H2lxO leads to the formation of carboxylic acid, some of which contains the 18 O label and some of which does not (Hatakeyama et al., 1981), suggesting mechanisms such as the following ... 

MacPhee, R. D., Eye, M. G., Parkinson, E. E., A Method for Monitoring Organic Lead in the Atmosphere, Air Pollution Control District, County of Los Angeles, in Cholak, J., Arch. Environ. Health 8 [1964] 222/31. 

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