The positive relationship between air pollution and allergic diseases such as allergic rhinitis and asthma was suggested by epidemiological studies. Comparison of the concentrations of nitrogen dioxide (NO₂), sulfur dioxide (SO₂), suspended particulate matter (SPM) and increased prevalence of allergic diseases indicated that air pollutants may stimulate some mechanisms in allergic response. This paper reviews the effects of SPM on mucociliary clearance, alveolar macrophage functions, IgE antibody production, mast cell function and hyperreactivity. The validation of immunological parameters in animal experiments and future direction of im munol ogical approach are discussed.

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There were some tragic acciednts of the release of cryogenic liquefied gases and toxic chemicals and it was found that atmospheric dispersion of these vapor cloud was much different from the well-known dispersion behavior of trace gases. Therefore, many dispersion experiments were carried out in order to understand the behavior of heavy gases in U. S. and Europeian countries. Mathematical models were also developed for the risk analysis of the concerned facilities. These haevy gas diffusion models are reviewed here.

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The adsorption of 1, 1, 1-trichloroethane (MC), one of the volatile chlorinated hydrocarbon, onto activated carbon fibers (ACFs) in gaseous phase was investigated. The adsorption capacities of ACFs were large according to their grade number. The amount adsorbed was large at lower temperature, so that the adsorption of MC onto ACF was considered to be aphysical ad-sorption.
Applying the Duhinin-Radushkevich (D-R) equation to the adsorption isotherms, ACF could be classified into 2 types. There is a difference concerning the adsorption sites of MC in both types, and the difference is considered to be due to the pore size distributions of ACFs.

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Evaluated a significant enhancement of unscheduled DNA synthesis (UDS) in airway epithelial cells following exposure to diesel exhaust, several in vitro and in vivo experiments were carried out. On the in vivo exposure, F344 SPF rats were divided into three groups according to the content of exhaust; the whole-exhaust exposure (WE) group, the filtered-exhaust exposure (FE) group, and clean air exposure (control) group. After one month of exposure, no significant difference in the mean number of grains per UDS positive cell (G/N) was observed among the three groups. After 6 months exposure, significant increase of UDS was noted in the tracheal epithelium of WE group as compared to FE and control groups.
The maximal UDS in G/N was observed at 6 months of exposure, showing three times higher value than the other two groups. There was no significant difference between FE and control groups over the whole exposure period. It suggested that the particle and its content, butnot the gaseous component, play an important role in UDS. Normal cell division was not affected by diesel particle exposure. The bronchiolar epithelium exposed to WE for 12 months also indicated a significantly higher UDS value than the control group.
Then, various concentration of diesel exhaust particle (DEP) were added to the culture medium, and UDS was estimated on the rat tracheal epithelial cells. Augmented, dose-dependent UDS rate was also observed under in vitro exposure of DEP to the rat tracheal epithelia.
When dilluted benzene-ethanol extract of DEP was added to the culture medium for the rat tracheal epithelia and the human bronchial cells which were obtained surgically, UDS rate increased in both the rat and the human. Scheduled cell division in the rats were seen morefrequently than those in the humans.
Our data demonstrated that DEP are an inducible substrate for UDS to both the rat tracheal epithelium and the human bronchial epithelium.

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Florisil and silica gel were evaluated as trapping adsorbents for 137 kinds of airborne pesticides by investigating their retention efficiencies (recovery when a pesticide in solution was placed into the trap through which air was passed) and sampling efficiency (recovery when a vaporized pesticide passed with air through the trap). The both adsorbents showed the same characteristics and were useful for trapping most of the airborne pesticides. The sampling efficiencies and the retention efficiencies were approximate for Florisil, but tne formers were high values than the latters about the several pesticides for silica gel.
Among the pesticides investigated, captafol, DNBP, and pival were not well recovered with acetone from the adsorbents. CDEC, DBCP, disulfoton, ethiofencarb, formothion, methyltrithion, phorate, propaphos and trithion were not quantitatively sampled onto the sampling mediums due to breakthrough, oxidation and other decompositions. BRP, Chloroneb, ciodrin, CMDP, CNA, DCPA, HCH, heptachlor, lenacil, MCC, MEP, MPP, PCNB, TPN, phosphamidon, triflumizole showed somewhat lower sampling efficiencies due to large sampling volume and/or sampling temperature. However, these pesticides could be well sampled and analyzed by selecting a suitable sampling volume or period. The other 105 pesticides could be well collected onto the trap with 2-19 m³ of air sample.
he proposed method resulted in several advantages as follows:
1) The adsorbents were easily and inexpensively obtained from the manufactures.
2) They were purified by simple decantation with acetone.
3) No special wares, equipments and techniques were required for sampling and analysing the pesticides.
4) Necessary sampling volume was easily attained at 13 l/ min of sampling rate.
5) The most pesticides were effectively sampled into the adsorbents and well recovered from the adsorbents with acetone without any decomposition except for several pesticides.

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The lung weight of CD-1 female mice exposed to NO₂ increased with the augmentation of NO₂ concentration, and the increase was reduced by Zn pretreatment. The Ca content in lung after NO₂ exposure had increased and the rise was depressed by Zn pretreatment The Zn content in lungs of saline-pretreated mice exposed to 40 and 50 ppm NO₂ showed a significant increase. There was a significant increase of Fe content in lung at 15 ppm NO₂ exposure. Zn pretreatment inhibited significantly the augmentation of Fe content in lung exposed to 15 ppm NO₂. The Cu content in lung after 35 ppm NO₂ exposure had incraesed significantly and the rise was depressed by Zn pretreatment. The Mg content in serum after NO₂ exposure increased relative to the control value, while the Ca content decreased remarkably. Zn pretreatment protected against the augmentation of pulmonary Ca content ad the drop of serum Ca content. It is considered that Zn depresses the influx of serum Ca to lung caused by NO₂ exposure. As well as lung wet weight, the ratio of Ca content in serum to that in lung can be used as a measure of the effect of Zn against lung edema caused by NO₂ exposure.

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Analytical method of nitobenzenes in ambient air was developed. Nitrobenzenes in ambient air sample was collected into a Tenax-TA Tube, using a sucking pump at a flow rate of 1l/min. This tube was inserted into the carrier gas line of the GC/ MS equipped with a three way cock and then heated to drive off the adsorbed analytes to the analytical column at 280°C for 20min. The desorbed analytes were preconcentrated in the precolumn cooled with liquid oxygen. After thermal desorption, GC/MS analysis was performed. The recoveries for standard solution contained 200 pg each of nitrobenzene, onitrotoluene, o-/m-/p-chloronitrobenzene were 90-104% with the coefficients of variation of 4.6-10.5%. Detection limit was 0.7mg/m³ for 30l of atmospheric air sample. Breakthrough volume of tested compounds was more than 1m³. Adsorbed compounds in the Tenax-TA tube was stable in 24 days. As the result of analysis of atmospheric air samples at 14 sites in Kitakyushu City, nitrobenzene was detected in every samples. Concentration of nitrobenzene at the sampling site close to a chemical plant reacbed 230ng/m³. p-chloronitrobenzene was detected at almost all sampling sites.

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