Analysis for Aerotoxicants

SUMMARY

For lack of space, methods for the determination of other types of aerotoxicants have not been discussed. For example, carbon monoxide-which has killed many individuals in confined areas and which is said to affect the central nervous system even at relatively low levels⁵⁵⁸ -has been reviewed elsewhere.⁵⁵⁹ Others like sulfur trioxide and nitrogen dioxide could be considered. Actually, long, thorough, and separate reviews on the analysis of each of the common air-pollutant gases would be invaluable.

The ideal situation in the analysis of these simple unique chemicals would be a relatively inexpensive little black box which would quantitatively measure the aerotoxicant in the airstream being pulled through the box. An alternative dry method would measure the aerotoxicant directly in the air over the distance covered by some laser beam. With the development of better monitoring techniques, improved manual techniques would also be necessary for calibration purposes.

Surprisingly, highly sensitive direct fluorimetric methods of analysis for most of the common gaseous pollutants are unavailable, and yet they could be readily developed. Some possibilities have been discussed in the text. Others are readily apparent. Thus, nitrogen dioxide could be determined fluorimetrically with 2,3-diaminonaphthalene⁵⁶⁰ or with some appropriate member of the large assortment of readily available o-diamines.

A bewildering number of analytical methods for the common atmospheric gases are available or are being developed. Methods of analysis are needed for the higher boiling and more toxic components of the air, many of which are of unknown composition. In addition, methods of analysis are unavailable and are badly needed for the huge class of "in-between" compounds present in the atmosphere. These are compounds which are neither common gases nor high-boiling solids.

The four main types of aerotoxicants which can affect human, animal, or plant life can be classified as bacterial, fungal, viral, and molecular. It is the analysis of the last of these that has been reviewed here.

The types of chemicals affecting human beings whose analysis has been reviewed include the aeromiserogens of the allergen family with their chronic and periodic effect on the individual's well-being; the aerocarcinogen family found in cigarette smoke, polluted air, and in the environment around us; the possible mutagens; and the lachrymators. Accumulation of some of these air pollutants has caused murderous air-pollution episodes⁵⁶¹ in the Meuse Valley of Belgium in December, 1930; in Donora, Pennsylvania, in October, 1948; in the hydrogen sulfide episode in Poza Rica, Mexico, in November, 1950; and in London in December, 1952. Air pollutants probably also play an important role in the alarming increase in emphysema.

The analysis of phytotoxicants has also been reviewed in this paper.

We must consider the total pollutant assault on human beings and other organisms if we are to properly evaluate the impact of any pollutant. Factors such as synergism, long-term effects of a pollutant, sudden aggravations of existing physiological problems, and the minor aggravations of lachrymators, sternutators, and headache-causers have to be considered.

As we obtain more and more information on the individual aerotoxicants we must turn our attention more and more to the mixtures around us. A reduction in the amount of one type of air pollutant or aerial organism may result in an overwhelming increase of a more toxic competitor. On the other hand, an increase in some air pollutant could have a synergistic effect on the physiological reaction of some other type of pollutant - chemical, bacterial, fungal or viral. Thus, it has been shown that during Asian flu epidemics polluted cities experienced a 200% increase in illness while the relatively unpolluted cities had only a 20% increase.⁵⁶²

Viruses and viral fragments have been postulated as playing a role in carcinogenesis. One suggestion is that independent fragments of virus-like genetic material, perhaps assisted at certain stages in their existence by viruses proper, are the key to many naturally occurring tumors.⁵⁶³ In addition, there is the possibility that chemical carcinogens may have their effect mediated through viral agents or may react in combination with viruses.⁵⁶⁴

Another type of phenomena is the lethal or toxic synthesis. Thus, ozone, PAN, lachrymators, etc. can be synthesized in the polluted atmosphere while some allergens can be synthesized in airborne dusts from pre-allergens and some highly toxic chemicals can be synthesized in plants in contact with air pollutants. Thus, some forage crops in contact with high atmospheric concentrations of fluoride synthesize and accumulate the highly toxic fluoroacetate and fluorocitrate.⁵⁶⁵

On the basis of all these data I believe it is obvious that the total environment needs to be examined more thoroughly. I believe that analysis for just the primary aerotoxicants and the main atmospheric gases is not enough. Methods are needed for cofactors, irritants, antagonists, enhancers, sensitizers, pre-toxicants, etc. Analytical methods for many of these seemingly innocuous pollutants will be necessary because in the right mixture at the right moment these "harmless" chemicals may contribute to enhance, accelerate, or increase the duration of the physiological effect of the primary aerotoxicant.