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1014. Athletes for the wide open spaces
236
THE CHEMICALENVIRONMENT
propionylacetophenone, caproic acid and triethanolamine in the liquid, caused little irritation. The least toxic response was given by a sealer (AH-26) containing bisphenol diglycidyl ether as liquid and bismuth oxide, silver powder, titanium oxide and hexamethylenetetramine in the powder. It is noteworthy that in general the activity of each material proved to be fairly consistent from study to study. 1012. Detergent pollution well under control
Coughlin, F. J. (1965). Detergents and water pollution abatement. Am. J. publ. Hlth 55, 760. This review covers approximately the same ground and arrives at the same main conclusions as other recent appraisals of this subject (Cited in F.C.T. 1965, 3, 135). At present the concentration of detergent residues, mainly those of alkylbenzene sulphonate (ABS), in water supplies is not a matter of great concern, since residues almost invariably fall well below the recommended limit of 0-5 ppm ABS, a level which provides a safety factor of the order of 15,000. Moreover, detergent residues are of minor significance in the overall problem of water pollution. The most effective method of control lies in the increased use of biodegradable surface-active agents. 1013. Pulmonary lesions induced by ozone Gross, P., Scheel, L. D. & Stokinger, H. E. (1965). Ozone toxicity studies; destruction of alveolar septa--a precursor of emphysema? Med. thorac. 22, 376. Air pollution by ozone (03) appears to be increasing. A vigilant eye should be kept on the atmospheric levels of 03 attained in view of its ability to cause irritation of the respiratory tract and pulmonary congestion and oedema in industrial workers. Moreover, emphysema (destruction of fine structure of lungs) and acceleration of lung turnout development has been produced experimentally in animals following long-term exposure to 03 (Cited in F.C.T. 1965, 3, 871). The maximal permissible concentration of 03 in the atmosphere of factories in the USA is 0-1 ppm, but this is frequently exceeded in practice. In the present study, hamsters were exposed to 1 ppm 03 for 6 hr daily on 5 days/wk for a total of 268 exposures, and rabbits to 15-50 ppm 03 for 1 hr/wk for 49 wk. Chronic pneumonitis developed with obvious proliferation of alveolar cells and an increase in stromal reticulin fibres resulting in contraction of the alveolar septa. It is considered that these septal abnormalities may be a prelude to the disappearance of septal walls and hence to emphysema. 1014. Athletes for the wide open spaces Smith, L. E. (1965). Peroxyacetyl nitrate inhalation. Cardiorespiratory effects. Arehs envir. Hlth 10, 161. Peroxyacetyl nitrate (PAN), a photochemical air pollutant and a constituent of "smog", is known to be phytotoxic (Cited in F.C.T. 1964, 2, 277; ibid 1965, 3, 850) and to cause eye irritation. Since athletes have often reported pulmonary discomfort during and after competitive activity in smoggy atmospheres, the effect of PAN at a level of 0.3 ppm (equivalent to that found in heavy smog) on various cardiovascular parameters has been studied in young men during short periods of moderate exercise. PAN was found to produce a significant increase in the oxygen uptake during periods of exercise but had no effect during periods of rest. Since neither respiratory rate nor the volume of expired air was affected, PAN is presumed to increase the respiratory airway resistance, in common with the known effects of cigarette smoke and other air pollutants. It is suggested that studies
NATURAL PRODUCTS
237
of the effect of atmospheric pollutants on respiratory efficiency should be designed so as to include periods of exercise. 1015. Advantages of the British summer
Dugger, W. M., Jr., Mudd, J. B. & Koukol, Jane (1965). Effect of PAN on certain photosynthetic reactions. Archs envir Hlth 10, 195. In the previous abstract, brief mention was made of the phytotoxic potential of peroxyacetyl nitrate (PAN). Concentrations as low as 0.25 ppm of PAN can cause irreversible plant damage but resistance to this effect can be achieved by placing the plants in the dark for 72 hr prior to PAN exposure (Cited in F.C.T. 1964, 2, 278). Attention has now been switched from the intact plant to the isolated chloroplast, the subceUular structure in which photosynthesis takes place. The effect of PAN on three photosynthetic reactions has been studied, namely photosynthetic phosphorylation [which produces adenosine triphosphate (ATP)], the reduction of nicotinamide-adenine dinucleotide phosphate (NADP) and finally carbon dioxide (CO2) fixation. The first two reactions are "light reactions" and occur in the chlorophyll-containing grana within the chloroplast, whereas CO2 fixation is a "dark reaction" and occurs in the stroma of the chloroplast. Although CO2 fixation does not require light, ATP and reduced NADP are necessary for the synthesis of hexose, a final product of photosynthesis. When PAN was bubbled through reaction mixtures which contained chloroplasts isolated from the leaves of spinach or beans and left in the light, all three photosynthetic reactions were inhibited. These inhibitory effects of PAN could be prevented by adding ascorbic acid to the reaction mixture. These results thus confirm that the phytotoxicity of PAN is due to interference with essential photosynthetic reactions. It is interesting that ascorbic acid, which destroys PAN in solution, protects plants on which it is sprayed from photochemical smog injury (Freebairn, J. Air Pollut. Control Ass. 1960, 10, 314).
NATURAL PRODUCTS 1016. It's those lactones again
Dickens, F. & Jones, H. E. H. (1965). Further studies on the carcinogenic action of certain lactones and related substances in the rat and mouse. Br. J. Cancer 19, 392. Dickens, F. & Jones, H. E. H. (1964). Effect of lactones and related substances in rats after oral administration. Rep. Br. Emp. Cancer Campn No. 42, p. 142. Dickens, F., Jones, H. E. H. & Waynforth, H. B. (1964). Carcinogenic action of lactones and related substances on the rat lung. Rep. Br. Emp. Cancer Campn No. 42, p. 143. Dickens, F. & Cooke, Judith (1965). Rates of hydrolysis and interaction with cysteine of some carcinogenic and related substances. Br. J. Cancer 19, 404. A variety of lactones and related compounds has been tested for carcinogenic activity by following the appearance of local tumours (sarcomas) at the site of repeated subcutaneous injection into rats, and from the results obtained by Dickens and his coworkers structural requirements for lactone carcinogenicity have been postulated (Cited in F.C.T. 1963, 1, 158; ibid 1964, 2, 64). In their long series of studies aflatoxin proved to be the most potent carcinogen of all compounds tested (ibid 1964, 2, 627). Further tests have been conducted by Dickens & Jones (1965, cited above) on the following compounds: coumarin (I), since the coumarin ring is contained in aflatoxin; the closely-related coumalic acid (II); N-ethyl maleimide (IU); maleic hydrazide (IV); a//-dimethylmaleic anhydride (V); bovolide (VI), a natural butter flavouring; succinic
THE CHEMICALENVIRONMENT
propionylacetophenone, caproic acid and triethanolamine in the liquid, caused little irritation. The least toxic response was given by a sealer (AH-26) containing bisphenol diglycidyl ether as liquid and bismuth oxide, silver powder, titanium oxide and hexamethylenetetramine in the powder. It is noteworthy that in general the activity of each material proved to be fairly consistent from study to study. 1012. Detergent pollution well under control
Coughlin, F. J. (1965). Detergents and water pollution abatement. Am. J. publ. Hlth 55, 760. This review covers approximately the same ground and arrives at the same main conclusions as other recent appraisals of this subject (Cited in F.C.T. 1965, 3, 135). At present the concentration of detergent residues, mainly those of alkylbenzene sulphonate (ABS), in water supplies is not a matter of great concern, since residues almost invariably fall well below the recommended limit of 0-5 ppm ABS, a level which provides a safety factor of the order of 15,000. Moreover, detergent residues are of minor significance in the overall problem of water pollution. The most effective method of control lies in the increased use of biodegradable surface-active agents. 1013. Pulmonary lesions induced by ozone Gross, P., Scheel, L. D. & Stokinger, H. E. (1965). Ozone toxicity studies; destruction of alveolar septa--a precursor of emphysema? Med. thorac. 22, 376. Air pollution by ozone (03) appears to be increasing. A vigilant eye should be kept on the atmospheric levels of 03 attained in view of its ability to cause irritation of the respiratory tract and pulmonary congestion and oedema in industrial workers. Moreover, emphysema (destruction of fine structure of lungs) and acceleration of lung turnout development has been produced experimentally in animals following long-term exposure to 03 (Cited in F.C.T. 1965, 3, 871). The maximal permissible concentration of 03 in the atmosphere of factories in the USA is 0-1 ppm, but this is frequently exceeded in practice. In the present study, hamsters were exposed to 1 ppm 03 for 6 hr daily on 5 days/wk for a total of 268 exposures, and rabbits to 15-50 ppm 03 for 1 hr/wk for 49 wk. Chronic pneumonitis developed with obvious proliferation of alveolar cells and an increase in stromal reticulin fibres resulting in contraction of the alveolar septa. It is considered that these septal abnormalities may be a prelude to the disappearance of septal walls and hence to emphysema. 1014. Athletes for the wide open spaces Smith, L. E. (1965). Peroxyacetyl nitrate inhalation. Cardiorespiratory effects. Arehs envir. Hlth 10, 161. Peroxyacetyl nitrate (PAN), a photochemical air pollutant and a constituent of "smog", is known to be phytotoxic (Cited in F.C.T. 1964, 2, 277; ibid 1965, 3, 850) and to cause eye irritation. Since athletes have often reported pulmonary discomfort during and after competitive activity in smoggy atmospheres, the effect of PAN at a level of 0.3 ppm (equivalent to that found in heavy smog) on various cardiovascular parameters has been studied in young men during short periods of moderate exercise. PAN was found to produce a significant increase in the oxygen uptake during periods of exercise but had no effect during periods of rest. Since neither respiratory rate nor the volume of expired air was affected, PAN is presumed to increase the respiratory airway resistance, in common with the known effects of cigarette smoke and other air pollutants. It is suggested that studies
NATURAL PRODUCTS
237
of the effect of atmospheric pollutants on respiratory efficiency should be designed so as to include periods of exercise. 1015. Advantages of the British summer
Dugger, W. M., Jr., Mudd, J. B. & Koukol, Jane (1965). Effect of PAN on certain photosynthetic reactions. Archs envir Hlth 10, 195. In the previous abstract, brief mention was made of the phytotoxic potential of peroxyacetyl nitrate (PAN). Concentrations as low as 0.25 ppm of PAN can cause irreversible plant damage but resistance to this effect can be achieved by placing the plants in the dark for 72 hr prior to PAN exposure (Cited in F.C.T. 1964, 2, 278). Attention has now been switched from the intact plant to the isolated chloroplast, the subceUular structure in which photosynthesis takes place. The effect of PAN on three photosynthetic reactions has been studied, namely photosynthetic phosphorylation [which produces adenosine triphosphate (ATP)], the reduction of nicotinamide-adenine dinucleotide phosphate (NADP) and finally carbon dioxide (CO2) fixation. The first two reactions are "light reactions" and occur in the chlorophyll-containing grana within the chloroplast, whereas CO2 fixation is a "dark reaction" and occurs in the stroma of the chloroplast. Although CO2 fixation does not require light, ATP and reduced NADP are necessary for the synthesis of hexose, a final product of photosynthesis. When PAN was bubbled through reaction mixtures which contained chloroplasts isolated from the leaves of spinach or beans and left in the light, all three photosynthetic reactions were inhibited. These inhibitory effects of PAN could be prevented by adding ascorbic acid to the reaction mixture. These results thus confirm that the phytotoxicity of PAN is due to interference with essential photosynthetic reactions. It is interesting that ascorbic acid, which destroys PAN in solution, protects plants on which it is sprayed from photochemical smog injury (Freebairn, J. Air Pollut. Control Ass. 1960, 10, 314).
NATURAL PRODUCTS 1016. It's those lactones again
Dickens, F. & Jones, H. E. H. (1965). Further studies on the carcinogenic action of certain lactones and related substances in the rat and mouse. Br. J. Cancer 19, 392. Dickens, F. & Jones, H. E. H. (1964). Effect of lactones and related substances in rats after oral administration. Rep. Br. Emp. Cancer Campn No. 42, p. 142. Dickens, F., Jones, H. E. H. & Waynforth, H. B. (1964). Carcinogenic action of lactones and related substances on the rat lung. Rep. Br. Emp. Cancer Campn No. 42, p. 143. Dickens, F. & Cooke, Judith (1965). Rates of hydrolysis and interaction with cysteine of some carcinogenic and related substances. Br. J. Cancer 19, 404. A variety of lactones and related compounds has been tested for carcinogenic activity by following the appearance of local tumours (sarcomas) at the site of repeated subcutaneous injection into rats, and from the results obtained by Dickens and his coworkers structural requirements for lactone carcinogenicity have been postulated (Cited in F.C.T. 1963, 1, 158; ibid 1964, 2, 64). In their long series of studies aflatoxin proved to be the most potent carcinogen of all compounds tested (ibid 1964, 2, 627). Further tests have been conducted by Dickens & Jones (1965, cited above) on the following compounds: coumarin (I), since the coumarin ring is contained in aflatoxin; the closely-related coumalic acid (II); N-ethyl maleimide (IU); maleic hydrazide (IV); a//-dimethylmaleic anhydride (V); bovolide (VI), a natural butter flavouring; succinic