Photochemical Oxidants
INDEXCONTENTSPat' ENVIRONMENTAL HEALTH CRITERIA FOR PHOTOCHEMICAL OXIDANTS 11 1. SUMMARY AND RECOMMENDATIONS FOR FURTHER RESEARCH AND OTHER ACTION 13 1.1 Summary ............................ 13 .1 Chemistry and analytical methods .............. 13 .2 Sources of photochemical oxidants and their precursors ..... 13 .3 Environmental concentrations and exposures .......... 14 .4 Effects on experimental animals ............... 15 .5 Effects on man ....................... 16 1.1.5.1 Controlled exposures ................ 16 1.1.5.2 Industrial exposure ................. 17 1.1.5.3 Community exposure ................ 17 1.1.6 Evaluation of health risks .................. 18 1.2 Recommendations for further research and other action ........ 19 1.2.1 Health effects research ................... 19 1.2.2 Photochemical oxidant control ................ 20 2. CHEMISTRY AND ANALYTICAL METHODS 20 2.1 Chemical and physical properties .................. 20 2.1.1 Ozone .......................... 20 2.1.2 Peroxyacylnitrates ..................... 21 2.1.3 Other oxidants ....................... 22 2.2 Atmospheric chemistry ...................... 22 2.3 Measurement of'photochemical oxidant concentrations . ........ 23 2.3.1 Sampling ......................... 23 2.3.2 Analytical methods ..................... 24 2.3.2.1 Ozone ....................... 24 2.3.2.2 Total oxidants ................... 25 2.3.2.3 Peroxyacetylnitrate ................. 26 3. SOURCES OF PHOTOCHEMICAL OXIDANTS AND THEIR PRECURSORS 26 3.1 Natural sources ......................... 26 3.2 Man-made sources of'oxidant precursors ............... 27 3.3 Indoor sources .......................... 28 3.4 Oxidant-precursor relationships ................... 28 4. ENVIRONMENTAL CONCENTRATIONS AND EXPOSURES 29 4.1 Background concentrations .................... 29 4.2 Rural areas ........................... 29 4.3 Urban areas ........................... 31 4.4 Indoor concentrations ....................... 37 5. EFFECTS ON EXPERIMENTAL ANIMALS 37 5.1 Absorption of ozone ....................... 385.2 Effects on the respiratory system .................. 38 5.2.1 Morphological changes ................... 38 5.2.1.1 Short-term exposure (24 h or less) ........... 38 5.2.1.2 Prolonged and repeated exposures ........... 39 5.2.2 Functional changes ..................... 41 5.2.2.1 Short-term exposure (24 h or less) ........... 41 7. 5.2.2.2 Prolonged and repeated exposures ........... 43 C 5.2.3 Biochemical changes .................... 43 5.2.3 1 Effects indicating possible mechanisms of action . r . . 43 5.2.3.2 Biochemical effects at the subcellular level ....... 45 5.2.3.3 Extracellular effects ................. 47; 5.2.4 Carcinogenicity ...................... 48 i 5.2.5 Tolerance to ozone ..................... 48 5.2.6 Effects on the host defence system . .............. 51 5.2.7 Interaction of ozone with bronchoactive and other chemicals ... 54 5.3 Systemic reactions and other effects ................. 56 5.3.1 Effects on growth ...................... 56 R 5.3.2 Haematological effects ................... 56' 5.3.2.1 Short-term exposure (24 h or less) ........... 56; 5.3.2.2 Prolonged and repeated exposures ........... 57 ; 5.3.3 Effects on reproduction ................... 58 5.3.4 Behavioural and related changes ............... 58 5.3.4.1 Short-term exposure (24 h or less) ........... 58 5.3.4.2 Prolonged and repeated exposures ........... 59 5.3.5 Miscellaneous systemic reactions to lung damage ........ 59 5.4 Mutagenicity .......................... 60 5.5 Summary table .......................... 61 6. EFFECTS ON MAN 66 6.1 Controlled exposures ....................... 66j 6.1.1. In vitro effects on human tissues ................ 66 i 6.1.2 Sensory effects ....................... 66 6.1.3 Effects on respiratory function ................ 68 6.1.3.1 Exposure to ozone ................. 68 6.1.3.2 Exposure to mixtures of ozone and other air pollutants . . 71! 6.1.3.3 Exposure to peroxyacetylnitrate alone or in combination with carbon monoxide ............... 71 6.1.3.4 Exposure to irradiated automobile exhaust ....... 72 6.1.3.5 Exposure to ambient air containing elevated concentrations f ofoxidants ................... 72 6.1.4 Changes in electroencephalograms .............. 73 6.1.5 Chromosomal effects .................... 73 6.2 Industrial exposure ........................ 73 J 6.3 Community exposure ....................... 75 6.3.1 Mortality ......................... 75 6.3.2 Annoyance and irritation .................. 76 6.3.3 Athletic performance .................... 77 6.3.4 Effects on children ..................... 79 6.3.5 Effects on the incidence of acute respiratory and cardiovascular diseases ......................... 81 6.3.6 Effects on the prevalence of chronic respiratory diseases and on pulmonary function .................... 82 6.3.7 Effects on patients with pre-existing diseases .......... 83 6.3.7.1 Asthma ...................... 836.3.7.2 Chronic respiratory diseases ............. 83 6.3.8 Cancer .......................... 84 6.3.9 Motor vehicle accidents ................... 84 6.4 Summary tables ......................... 84 7. EVALUATION OF HEALTH RISKS FROM EXPOSURE TO PHOTOCHEMICAL OXIDANTS 92 7.1. Exposure conditions ....................... 92 7.2 Exposure-effect relationships .................... 93 7.2.1 Animal data ........................ 93 7.2.2 Controlled human exposures ................. 94 7.2.3 Industrial exposure ..................... 95 7.2.4 Community exposure .................... 96 7.3 Guidelines on exposure limits ................... 96 REFERENCES ............................. 98
|