Noise sensitivity and subjective health: questionnaire study conducted along trunk roads in Kusatsu, Japan.

A questionnaire study was conducted in a residential area along trunk roads in Kusatsu, Japan, in order to investigate the association between noise exposure, noise sensitivity, and subjective health. Subjective health of the respondents was measured by the General Health Questionnaire (GHQ-28) which yields the total score as an index of psychiatric disorder and four subscales. Noise sensitivity was measured by the improved version of the Weinstein's noise sensitivity scale named WNS-6B. The original WNS and a single question directly asking respondents' noise sensitivity were also applied to confirm the validity of the WNS-6B for investigating the effects of road traffic noise on subjective health. Respondents were also asked about disturbances of daily life due to noise exposure to find the cause of the health effects. Three hundred and twenty three answers were entered into the analysis. Applying the WNS-6B as the noise sensitivity measurement scale, a significant correlation was found between subjective health and noise exposure in the noise-sensitive group, while no significant correlation was observed in the insensitive group. These results suggest that the adverse health effects may exist especially in the sensitive group. Application of the other two noise sensitivity measurement scales showed no significant relationship either in the sensitive group or in the insensitive group. The WNS-6B would have greater advantage for detecting adverse health effects than the other scales. Furthermore, the primary cause of the adverse health effect was investigated. The results of the analysis indicated that the adverse health effects were mainly caused by the sleep disturbance and were not caused by hearing interference.

[Effects of aircraft noise on preschool children's misbehaviours: results of research around the Kadena and Futenma airfields in Okinawa].

OBJECTIVES: To investigate the association between aircraft noise exposure as expressed by Weighted Equivalent Continuous Perceived Noise Level (WECPNL) and preschool children's misbehaviours around the Kadena and Futenma airfields in Okinawa. METHODS: A questionnaire survey on children's misbehaviour was conducted in nursery schools and kindergartens around the Kadena and Futenma airfields. The children living around the Kadena airfield were divided into four groups according to WECPNL at their residences and those around the Futenma airfield into three groups according to WECPNL. The subjects were 1,888 male and female preschool children, 3 to 6 years of age, whose parents, caregivers, and teachers answered the questions. The answers used for the analysis were limited to those of respondents fulfilling the following conditions: parents living with their children, fathers with a daytime job, and mothers with a daytime job or no job. Thus, the number of valid answers was 1,213. The responses were analysed using logistic regression models taking the number of misbehaviours related to the items of Biological Function, Social Standard, Physical Constitution, Movement Habit, or Character as the dependent variables, and WECPNL, age, sex, size of family, birth order, mother's age at birth, mother's job, caregiver's career, and category of subject as the independent variables. RESULTS: A significant dose-response relationship was found between the odds ratio and WECPNL for the outcomes of Physical Constitution around the Kadena and Futenma airfields. CONCLUSIONS: It would be reasonable to conclude that the aircraft noise exposure is a factor that increases the number of preschool children's misbehaviours.

[Association between the rates of low birth-weight and/or preterm infants and aircraft noise exposure].

OBJECTIVES: Intense noise exposure having been observed in vicinal areas around the U.S. military airfields in Okinawa, Japan, suggests the possibility of adverse effects on fetal growth, as studies have reported such effects around other airfields. This study analyzes the birth records in Okinawa prefecture and investigates whether lower birth weights of infants and shorter gestation periods are observed around the airfields. METHODS: The records of 160,460 births in 15 municipalities around the Kadena and Futenma airfields from 1974 to 1993 were subjected to analysis. Average WECPNL among residents in each municipality was calculated as a measure of noise exposure, since the birth records did not contain information on precise birth addresses but only the municipalities. The odds ratios of low birth weight, i.e. under 2,500 grams, and preterm birth, i.e. less than 37 weeks, were obtained by multiple logistic regression analysis with adjustment for the primary factors that would be related to fetal growth. The factors included sex, maternal age, live birth order, occupation of householder, legitimacy of the infant, year of birth and interaction between maternal age and live birth order. RESULTS: The logistic regression analysis showed a significant dose-response relationship between low birth weight and noise exposure. The significance probability of trend test was less than 0.0001. The adjusted odds ratio was 1.3 in the highest noise exposure area, which was Kadena Town, located in the immediate vicinity of the Kadena airfield. Significantly higher rates of preterm births were also found across the noise exposed municipalities. Although the obtained results were not adjusted for some confounding factors like smoking habit, another survey conducted by the present authors did not show particular differences in the female smoking rate between Kadena Town and the other municipalities around the Kadena airfield. CONCLUSION: Aircraft noise exposure is most likely to cause adverse effects on fetal growth, raising the rates of low birth weight and preterm infants around the Kadena airfield.