Many procedures of optimum design of air monitoring networks were proposed since 1970 s. To have these procedures useful for optimum network design, spatial distributions of air pollutant concentration and their statistical properties should not vary much by seasons and years. Analysis of monitoring data obtained from an existing network showed that spatio-temporal structure of the data extremely changed during 1977 to 1988. Optimum networks produced by some conventional procedures also changed year by year. We carried out surveys six times to measure daily average concentration of NO₂ during several days each at dense grid points. Effectiveness of the survey was examined as a strategy to detect yearly variation of the air pollution fields and to enhance estimate accuracy of concentration in an area. Based on these analyses and surveys, we proposed the following basic policy to design an air monitoring network: 1) A rigorous optimum network should not be aimed at based on the model fields that do not include the annual and seasonal variation properly. 2) A network should be determined based on the stable spatio-temporal variation of concentration evaluated by analysis of actual data over a long period . 3) Supplemental measurements are necessary to find out the accuracy of monitoring and to obtain essential data for network design of the next generation.

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The concentration and the discharging rate of pesticides were investigated in a streamlet flowing through the golf links named as “D”. The water samples were collected once a week for two years. From the regular weekly observations, the herbicides simazine, atrazine and oxdiazon, and the insecticides diazinon and fenitrothion were detected. But atrazine was not listed on the application record obtained from D golf links, and fenthion, listed on the record, was not detected. The respective maximum values of the net concentrations of these pesticides in the discharge from D golf links were at 8.46, 1.71, 6.36, 0.42 and 0μg·1^-1 in the first year, and 32.7, 1.20, 3. 46, 0.02 and 5.64μg·1^-1 in the second year. None of these pesticides contaminated the runoff water from the neighboring upstream forested area. From the regular observation, the annual loading of simazine, atrazine, oxadiazon, diazinon and fenitrothion were calculated as 1, 180, 167, 512, 95 and 0, g·km^-2·y^-1 in the first year, and 754, 54, 55, 0, 73g·km^-2·y^-1 in the second year, respectively. The discharging rates calculated from the loading and the applied amount of each pesticide were at 3.1, 2.1, 0.9, 0 and 0 % for simazine, oxadiazon, diazinon, fenitrothion and fenthion in the first year, respectively. In the second year, 3.7% of the applied amount of simazine and 0.18 of that of fenitrothion were discharged. The changes of pesticide loadings were also investigated during five storm runoff events (6.5-188mm). The concentrations of pesticdes varied to a great extent with each storm runoff event. The loading rates depended on the length of the period after the applications rather than being correlated with the amounts of rainfall. The largest loadings of these events were equal to 12, 45, 83, 100 and 130% of the annual loadings of oxadiazon, daizinon, simazine, fenitrothion and atrazine calculated from the regular weekly observations, respectively.

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Examination was made of the urinary cadmium excretion of schoolchildren living near a zinc refinery. The subjects consisted of 202 first to fifth grade boys and 195 girls living near the refinery. 109 sixth grade girls of the same city served as the control. Urinary cadmium (Cd), specific gravity (SG), and creatinine (cre) were determined in 1993. Cd pollution was mainly from the soil due to dustfall from a zinc smelting factory. The geometric means of urinary Cd of first to fifth grade boys (girls) were 0.12 (0.16), 0.12 (0.17), 0.12 (0.18), 0.12 (0.17) and 0.16 (0.19)μg/l (adjusted by SG at 1.024), respectively. This parameter of urinary Cd of fifth grade boys was statistically significantly higher than that of other grade boys as determined by Ryan′s multiple comparison (p<0.01), though the significance disappeared by SG or cre adjustment. Urinary Cd of sixth grade girls near the zinc refinery was compared with that of groups of the same grade situated away from the refinery. Their geometric means of urinary Cd excretion were essentially the same. It is thus evident that there is no distinctive increase in urinary Cd of the elementary school pupils near the zinc refinery.

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The effects of cadmium exposure on systolic and diastolic blood pressure (SBP & DBP) of residents in a cadmium-polluted area were examined. The variables were age, urinary cadmium (Cd), sodium (Na), potassium (K), N-acetyl-β-D-glucosaminidase (NAG), creatinine (cre), serum total cholesterol, height and weight. Drinking and smoking habits, treatment and family histories of hypertension (HT) were also examined. The subjects were 113 males and 271 females from 40 to 84 years in age. The geometric mean of Cd was 1.81μg/g cre in males and 2.25μg/g cre in females. Significant increase in SBP in subjects having family histories of HT was recognized in females after correction for age. No statistical significance of Cd, NAG, Quetelet index (BMI), DBP, percentage of HT medication, NaCI intake, Na/K, total cholesterol, and amount of smoking and drinking was recognized for groups divided by family histories of HT. Multiple regression analysis indicated drinking and treatment for HT to be closely associated with SBP and DBP in males. In females, age, BMI, Na/K and treatment for HT were associated with SBP and DBP. Family histories of HT in females were also weakly but significantly associated with SBP. Multivariateanalysis failed to show relation between urinary Cd and human blood pressure.

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In various plots of rice paddy fields applied with different amounts of rice straw or compost, growth of rice plants, soil Eh, methane concentrations in soil gas, and methane emission rates were measured over the cultivation period. The number of tiller of rice plants increased during June at different rates depending on the plots. During the tillering stage the soil Eh dropped to about -100 mV in almost all the plots. The Eh raised after the midseason drainage, but after that the Eh dropped again in some plots. The methane concentrations in the soil gas were more than 40% in the plots applied with rice straw even soon after the transplanting. At the tillering stage the concentrations were more than 30% in almost all the plots. The methane emission rates were very low soon after the transplanting and markedly increased at the maximum tiller stage. At this time the emission rate from the plot applied with rice straw was the highest in all the plots. After the maximum tiller stage, the emission rates usually decreased and the number of tiller of rice plants per area of paddy field was positively correlated with the soil Eh and negatively correlated with the methane concentrations in soil gas and also with the methane emission rates. It was suggested that the difference of growth of rice plants affects the soil environment of paddy field and also the methane emission rate.

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Throughfall of the Japanese cedar and fir was collected weekly with precipitation in Mt. Oyama in the southwest of the Kanto Plain. Annual volume weighted mean pH of precipitation was 4.82, 4.76, and 4.94 from 1991 to 1993, respectively. The mean concentrations of major ions in precipitation in Mt. Oyama were lower than those in city area, Yokohama. However, there were very little differences between deposition fluxes of H⁺ and NO^3- in Mt. Oyama (31.4, 43.3 meq/m²/y on the three years average, respectively) and those in Yokohama. Annual amount of water of throughfall for both species was about 60-90% of that of precipitation and total deposition fluxes of major ions were about 2-4 times larger than those of precipitation. In major ions, Na⁺, Cl^-, and SO₄^2- were assumed to be originated mainly from atmospheric input, whereas K⁺, Ca²⁺, and Mg²⁺ were leached from the canopy. In the growing season, NO^3- was absorbed only to the fir canopy. It was indicated that K⁺ was leached from the canopy not only by ion exchange with W but also as the organic salt because of the high correlation between concentrations of total organic carbon (TOC) and K⁺ (r=0.85 and 0.80 for the cedar and fir canopy, respectively).

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The amounts of polycyclic aromtic compounds (PACs) i.e., l-nitropyrene (1-NP), benzo [a] pyrene (B [a] P) and pyrene retained in leaves of woody plants (azalea, mokkoku-tree and cherry) growing along arterial roads in Tokyo and the mutagenicity of leaf extract were followed over a period of one year to know their sasonal changes. Though mutagenicity (Salmonella typhimurium YG 1024, without S 9) and B [a] P did not show such clear seasonal change in the quantity in leaves, varying irregularly, but the amouts of pyrene and 1-NP showed a tendency to decrease on summer and to increase on winter. Particularly, the increase of pyrene on winter was remarkable, indicating that the amount of pyrene in leaves was dependent on the temperature. When a potted azalea was exposed to vehicle exhaust in the roadside of an arterial road, pyrene in the leaves increased with the elapse of exposure time and reached to about the same level as that of pyrene in the azalea leaves growing in the surroundings after 3 weeks, while B [a] P varied every determination after reached to the same level as that of surroundings by exposure for a few days. These results suggested that B [a] P is retained in leaves through adhesion of suspended particulate matter, while that pyrene in retained in leaves through adsorption of gaseous pyrene.Furthermore, the amount of 1-NP in leaves was relatively good correlated to that of pyrene, suggesting that the behavior of mutagenic 1-NP was dependent on that of pyrene.

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