Young male subjects were exposed to the following experimental conditions for 40 minutes, to clarify the effect on hearing of combined impact/steady-state noise.
(1) Exposure to a combination of 95dB steady-state noise and an impact noise of 121dB at the peak value and the time constant of 30m sec.: intervals between impacts were approximately 4sec. at a series of exposure and 250m sec. at the other.
(2) Exposure to a combination of 81dB steady-state noise and an impact noise 120dB at the peak value and the time constant of 10m sec.: intervals between peaks were approximately 1sec. at a series of exposure and 4sec. at the other.
Under the condition (1), the steady-state noise had a high sound pressure level (95dB); the test subjects' TTS growth at 4kHz was larger than at the exposure to only steady-state noise, but TTS growth at 1kHz was not so discernible. Under the condition (2), the steady-state noise had a comparatively low sound pressure level; the TTS growth at 4kHz as well as 1kHz was greater than at exposure to only steady-state noise. No noteworthy result was found concerning the relation between the change of “impact to impact” intervals and TTS values. These result indicate that impact noise at the condition of short “impact to impact” interval, and the steady-state noise with high sound pressure level invokes the acoustic reflex.

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Recently, various organochlorine pesticides have been quantitatively used in agricultural fields. In Japan, pesticides, particularly BHC isomers have consequently been discovered not only in farm produce but in the human body and human milk as well. A public hazard problem has been created herein.
The present study was undertaken in order to examine accumulation of BHC (α-, β-, γ- and δ-) isomers in rat bodies and excretion into urine following oral administrations.
Decomposition and isomerization of relative isomers in the tissues were discussed and determination of isomers in the blood, liver, kidneys and urine was carried out by means of gas chromatography.
Conclusions are as follows;
1. The level of the accumulation of BHC isomers in a rat body is β>>α>γ>δ. This difference of accumulation could depend on the chemical stability of isomers in the tissues.
2. BHC isomers not changed in rat tissues are excreted into the urine. Level of the quantity of excreted isomers for the period of a month is in the order of α>γ>>δ>β and, as to the length of their excretive period, β>α>γ>δ.
3. β-isomer is accumulated in a rat body when α-, γ- and δ-isomers are administrated. It can be presumed that isomers are isomerized to β-isomer in the tissues.

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Residues in organochlorine pesticides in milk pose a public hazard problem (particularly BHC isomers in Japan).
In the present study, milk, various cow fodders, soil and tissues from cows were collected from farms and residual BHC isomers were determined by means of gas chromatography to indicate from which fodders the BHC residues in milk resulted. It was also discussed how these contents would change in the near future.
Conclusions are as follows;
1: Rice straw contains 77% of the total BHC (95% of β-isomer) the daily intake of a cow. It is evident that residues in milk can be attributed to this straw.
2. BHC residues in rice straw are not primarily due to absorption from soil but due to attachment at the moment of dispersion. At present, amounts of BHC residues in the soil of rice fields have decreased as use of BHC is no longer permitted. For this reason, next season's rice straw may not be highly contaminated with residues.
3. From the amount of excreted β-BHC in milk, the β-isomer ingested daily by a cow is excreted to a great extent in the milk. It is also presumed that the accumulated isomer in the body decreases rapidly as the isomer intake decreases.

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An epidemiological survey has been carried out on the relationship between air pollution and mortality in Yokkaichi area covering from 1961 to 1970.
The death rate from obstructive respiratory diseases, especially bronchial asthma and emphysema, increased in the polluted area since 1966 and a significant difference in death rates was noticed among the polluted and non-polluted areas.
Mortality from these diseases obviously correlates with the degree of sulphur dioxide concentrations in 1968 and 1969.
The age-distribution of deaths from obstructive respiratory diseases was studied during a ten-year-period.
Deaths from bronchial asthma occurred at younger ages in the polluted areas, while deaths from emphysema were not encountered among women in the non-polluted areas.

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A quantitative and qualitative analysis of alkyl lead in the living body is most difficult to determine, therefore, direct microanalization by GC was done.
As for stationary phase, 7% Apiezon-L for 4ML, 1.5% SE-30 for 4EL and 1.4-BDS for 3ML and 3EL were more applicable.
Glass column and ECD as detector were used.
Detection limits reached 1×10^-9g. for 4ML and 1×10^-11g. for 4EL, 3ML and 3EL.
Extractions from biological samples were made using organic solvents after the sample had been acidified using HCl.
When more scattered peaks appeared in the extraction solution, 3ML and 3EL were extracted using 1% HNO₃ solution and trialkyl lead was transferred into the water layer and re-extracted using organic solvent for purification.

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A public relief-system has been established since 1965 in Yokkaichi for patients whose symptoms are regarded to have been caused by air pollution.
To date 710 patients came under this relief-system.
Results of epidemiological research on the present state of these patients:
1) Incidence of chronic obstructive pulmonary diseases had a tendency to increase in relation to the degree of air pollution.
2) Incidence in infants and old age groups was higher than in other age groups, and in males about twice that of females.
3) In Isozu, the highest polluted area in Yokkaichi, the number of new patients increased until 1965, and gradually decreased in parallel with a decrease in pollution level following construction of higher smoke stacks.
Bronchial asthma incidence peaks occurred at the beginning of air pollution, while peaks of chronic and asthmatic bronchitis occurred affer 2 to 3 years.

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