Asbestos in the surrounding air (Dutch)

The best approach to the problem of present day air pollution by asbestos is by analysis of the air in the various areas most suspect of pollution. These are: the great industrial cities, local sources of emission not situated in the large cities, and in areas of low concentration. Sampling in buildings and homes can also provide important data because it is there that the greater part of the population spends most of its time. The amount of asbestos mined increases every year and the asbestos fibres in the environment do not perish. The time needed for the growth of mesothelioma is 20 to 30 or more years from the first inhalation. The health risk in the population is still further worsened by accompanying synergistic effects such as tobacco smoke and other atmospheric impurities such as benzopyrene. Recent screening of the lungs of town dwellers that are not exposed by the nature of their occupation (e.g. housewives), brought to light the fact that 48 to 100% of their lungs contain chrysotile fibres. These air analyses can be a support for a later epidemiological study. Such analyses are best expressed in terms of mass, that is to say, in ng m^-3. The expression in fibres per m^-3 is dependent on the measurements of these fibres. Wesolowski reported that there were 6000 to 280,000 asbestos fibres per nanogram. As well as this concentration in mass, estimation of the size in distribution is of importance because this is connected with the inhalability of the asbestos fibres.