Norun Hjertager Krog

Exposure to traffic noise and markers of obesity

Objectives Limited evidence suggests adverse effects of traffic noise exposure on the metabolic system. This study investigates the association between road traffic noise and obesity markers as well as the role of combined exposure to multiple sources of traffic noise. Methods In a cross-sectional study performed in 2002–2006, we assessed exposure to noise from road traffic, railways and aircraft at the residences of 5075 Swedish men and women, primarily from suburban and semirural areas of Stockholm County. A detailed questionnaire and medical examination provided information on markers of obesity and potential confounders. Multiple linear and logistic regression models were used to assess associations between traffic noise and body mass index (BMI), waist circumference and waist–hip ratio using WHO definitions of obesity. Results Road traffic noise was significantly related to waist circumference with a 0.21 cm (95% CI 0.01 to 0.41) increase per 5 dB(A) rise in Lden. The OR for central obesity among those exposed to road traffic noise ≥45 dB(A) was 1.18 (95% CI 1.03 to 1.34) in comparison to those exposed below this level. Similar results were seen for waist–hip ratio (OR 1.29; 95% CI 1.14 to 1.45) but not for BMI (OR 0.89; 95% CI 0.76 to 1.04). Central obesity was also associated with exposure to railway and aircraft noise, and a particularly high risk was seen for combined exposure to all three sources of traffic noise (OR 1.95; 95% CI 1.24 to 3.05). Conclusions Our results suggest that traffic noise exposure can increase the risk of central obesity. Combined exposure to different sources of traffic noise may convey a particularly high risk.

Road traffic noise, sleep and mental health.

This study examines the relationship between road traffic noise, self-reported sleep quality and mental health. The study is cross-sectional and based on data from a survey conducted in Oslo, Norway, in 2000. Psychological distress (Hopkins Symptom Checklist, HSCL-25) was measured along with self-reported somatic health, sleep quality, noise sensitivity and socioeconomic variables. Questionnaire data were combined with modeled estimates of noise exposure. The total study sample consisted of 2898 respondents. After adjustment for potential confounders and stratifying for sleep quality, we found a positive, but not statistically significant association between noise exposure and symptoms of psychological distress among participants with poor sleep quality (slope=0.06, 95% CI: -0.02 to 0.13, per 10 dB increase in noise exposure). In the same sleep quality group, we found a borderline statistically significant association between noise exposure and a symptom level indicating a probable mental disorder (HSCL≥1.55) (odds ratio=1.47, 95% CI: 0.99-1.98, per 10 dB increase in noise exposure). We found no association between road traffic noise and mental health among subjects reporting good and medium sleep quality. The results suggest that road traffic noise may be associated with poorer mental health among subjects with poor sleep. Individuals with poor sleep quality may be more vulnerable to effects of road traffic noise on mental health than individuals with better sleep quality.

Road traffic noise and markers of obesity - a population-based study.

BACKGROUND Noise has been found to be associated with endocrine changes and cardiovascular disease. Increased cortisol levels and chronic sleep problems due to noise may increase the risk of obesity. OBJECTIVES We investigated the relationship between road traffic noise and obesity markers. Furthermore, we explored the modifying role of noise sensitivity, noise annoyance, and sleep disturbances. METHODS We used data from a population-based study, HUBRO (N=15,085), and its follow-up study HELMILO (N=8410) conducted in Oslo, Norway. Measurements were used to define body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), and these binary outcomes: BMI≥30kg/m(2), WC≥102cm (men)/88cm (women), and WHR≥0.90 (men)/0.85 (women). Modelled levels of road traffic noise (Lden) were assigned to each participants home address. Linear and logistic regression models were used to examine the associations. RESULTS The results indicated no significant associations between road traffic noise and obesity markers in the total populations. However, in highly noise sensitive women (n=1106) a 10dB increase in noise level was associated with a slope (=beta) of 1.02 (95% confidence interval (CI): 1.01, 1.03) for BMI, 1.01 (CI: 1.00, 1.02) for WC, and an odds ratio (OR) of 1.24 (CI: 1.01, 1.53) for WHR ≥0.85. The associations appeared weaker in highly noise sensitive men. We found no effect modification of noise annoyance or sleep disturbances. In a sub-population with bedroom facing a road, the associations increased in men (e.g. an OR of 1.25 (CI: 0.88, 1.78) for BMI ≥30kg/m(2)), but not in women. Among long-term residents the associations increased for BMI ≥30kg/m(2) (OR of 1.07 (CI: 0.93, 1.24) in men and 1.10 (CI: 0.97, 1.26) in women), but not for the other outcomes. CONCLUSION In an adult urban Scandinavian population, road traffic noise was positively associated with obesity markers among highly noise sensitive women. The associations appeared stronger among men with bedroom facing a street, representing a population with more accurately assigned exposure.

Occupation and the risk of bothersome tinnitus: results from a prospective cohort study (HUNT)

Objectives Estimates of occupation-specific tinnitus prevalence may help identify high-risk occupations where interventions are warranted. The authors studied the effect of occupation on prevalence of bothersome tinnitus and estimated the attributable fraction due to occupation. The authors also studied how much of the effect remained after adjusting for noise exposure, education income, hearing thresholds and other risk factors. Design A prospective cohort study. Setting A health survey of the Nord-Trøndelag county of Norway. Participants A sample of the general adult population (n=49 948). Primary outcome measure The primary outcome measure is bothersome tinnitus. Results Occupation had a marked effect on tinnitus prevalence. The effect of occupation on tinnitus was reduced in men by controlling for self-reported occupational noise exposure and in women by controlling for education and income. Adding hearing loss as a predictor increased the effect of occupation somewhat. In men, age-adjusted prevalence ratios of tinnitus ranged from 1.5 (workshop mechanics) to 2.1 (crane and hoist operators) in the 10 occupations with highest tinnitus prevalence. In women, the most important contribution to the tinnitus prevalence was from the large group of occupationally inactive persons, with a prevalence ratio of 1.5. Conclusion This study found a moderate association between occupation and bothersome tinnitus.

Heritability of hearing loss.

Background: Hearing impairment is one of the most common permanent disabilities in the western world. Although hearing ability normally declines with age, there is great individual variation in age of onset, progression, and severity, indicating that individual susceptibility plays a role. The aim of the present study was to explore the relative importance of genetic and environmental effects in the etiology of impaired hearing. Methods: From August 1995 to June 1997, the total adult population of Nord-Trøndelag County, Norway, was invited to take part in the Nord-Trøndelag Health Study. The survey included as an integrated project the Nord-Trøndelag Hearing Loss Study with pure-tone audiometry assessment of the standard frequencies 0.25, 0.5, 1, 2, 3, 4, 6, and 8 kHz on 51,574 participants aged 20 to 101 years. We obtained information from Statistics Norway identifying 11,263 sibling pairs. After age stratification, we assessed similarity in hearing thresholds between siblings using polychoric correlations. The contribution of genetic effects in hearing ability was calculated. Results: The upper limit of the heritability of hearing loss was 0.36. We found little evidence for sex differences in the relative importance of genetic effects. Conclusions: There is a substantial genetic contribution to individual variation in hearing thresholds.

A Population-Based Study on Nighttime Road Traffic Noise and Insomnia

Study Objectives: The aims of the present study were to investigate how nighttime road traffic noise relates to self‐reported symptoms of insomnia and sleep medication use. Methods: We used questionnaire data from the population‐based study Health and Environment in Oslo (HELMILO) (2009‐2010; n = 13019). The insomnia symptoms difficulties falling asleep, awakenings during the night, and waking up too early in the morning as well as self‐reported sleep medication use were included as outcomes. Modeled noise levels (Lnight) were assigned to each participants home address. For selecting covariates to the statistical model, we used a directed acyclic graph. The associations between noise and sleep were analyzed using logistic regression models. Results: After adjustment for potential confounders, we found an odds ratio (OR) of 1.05 (95% confidence interval [CI]: 1.01‐1.09) for the association between traffic noise and difficulties falling asleep, in the total study population. For the association between traffic noise and awakenings during the night, the OR was 1.04 (95% CI: 1.00‐1.08) and for waking up too early, the OR was 1.06 (95% CI: 1.02‐1.11). The effect estimates are given per 5‐dB increase in traffic noise level (Lnight). Self‐reported sleep medication use was not statistically significantly associated with traffic noise exposure. Conclusions: In an adult population from Oslo, traffic noise was associated with difficulties falling asleep and waking up too early. These findings indicate that sleep quantity may be compromised for individuals living in areas highly exposed to nighttime traffic noise.

Outdoor air pollution and risk for kidney parenchyma cancer in 14 European cohorts

Several studies have indicated weakly increased risk for kidney cancer among occupational groups exposed to gasoline vapors, engine exhaust, polycyclic aromatic hydrocarbons and other air pollutants, although not consistently. It was the aim to investigate possible associations between outdoor air pollution at the residence and the incidence of kidney parenchyma cancer in the general population. We used data from 14 European cohorts from the ESCAPE study. We geocoded and assessed air pollution concentrations at baseline addresses by land‐use regression models for particulate matter (PM10, PM2.5, PMcoarse, PM2.5 absorbance (soot)) and nitrogen oxides (NO2, NOx), and collected data on traffic. We used Cox regression models with adjustment for potential confounders for cohort‐specific analyses and random effects models for meta‐analyses to calculate summary hazard ratios (HRs). The 289,002 cohort members contributed 4,111,908 person‐years at risk. During follow‐up (mean 14.2 years) 697 incident cancers of the kidney parenchyma were diagnosed. The meta‐analyses showed higher HRs in association with higher PM concentration, e.g. HR = 1.57 (95%CI: 0.81–3.01) per 5 μg/m3 PM2.5 and HR = 1.36 (95%CI: 0.84–2.19) per 10−5m−1 PM2.5 absorbance, albeit never statistically significant. The HRs in association with nitrogen oxides and traffic density on the nearest street were slightly above one. Sensitivity analyses among participants who did not change residence during follow‐up showed stronger associations, but none were statistically significant. Our study provides suggestive evidence that exposure to outdoor PM at the residence may be associated with higher risk for kidney parenchyma cancer; the results should be interpreted cautiously as associations may be due to chance.

Impact of hearing impairment on spousal mental health: the Nord-Trondelag Health Study.

BACKGROUND Previous studies indicate that hearing loss have negative emotional implications also on spouses of the hearing impaired persons. We sought to assess the relationship between hearing impairment and spousal mental health in the general population. METHODS Pure tone audiometry and questionnaires were administered to the adult population of Nord-Trøndelag County, Norway (1996-97). In the age group between 20 and 44 years, the number of cases with hearing impairment was very low; thus, this age group was excluded from analyses. In total, 8607 couples with women over 44 years and 9530 couples with men over 44 years were identified. Associations between measured and self-reported hearing impairment and spousal self-reported symptoms of anxiety and depression, and subjective well-being were estimated. Stratified by sex and adjusting for several covariates, mental health in spouses of persons with hearing impairment was compared with that of spouses of persons with normal hearing using the general linear model. RESULTS Audiometrically measured hearing was not significantly associated with spousal mental health. Moderate relations between self-reported hearing and spousal mental health were observed. CONCLUSION Contrary to previous results based on self-reported hearing loss, our results based on audiometry did not indicate severe loss of mental health among spouses of persons with impaired hearing.

Nocturnal Road Traffic Noise Exposure and Children’s Sleep Duration and Sleep Problems

Almost half of the European Union (EU)’s population is exposed to road traffic noise above levels that constitute a health risk. Associations between road traffic noise and impaired sleep in adults have consistently been reported. Less is known about effects of noise on children’s sleep. The aim of this study was to examine the association between nocturnal road traffic noise exposure and children’s parental-reported sleep duration and sleep problems. The present cross-sectional study used data from The Norwegian Mother and Child Cohort Study. Parental report of children’s sleep duration and sleep problems at age 7 was linked to modelled levels of residential night-time road traffic noise. The study population included 2665 children from Oslo, Norway. No association was found between road traffic noise and sleep duration in the total study population (odds ratio (OR): 1.05, 95% confidence interval (CI): [0.94, 1.17]), but a statistically significant association was observed in girls (OR: 1.21, 95% CI: [1.04, 1.41]). For sleep problems, the associations were similar (OR: 1.36, 95% CI: [0.85, 2.16]) in girls. The ORs are presented for an increase of 10 dB. The findings suggest there is an association between road traffic noise and sleep for girls, underlining the importance of protecting children against excessive noise levels.

Effects of Changed Aircraft Noise Exposure on Experiential Qualities of Outdoor Recreational Areas

The literature indicates that sound and visual stimuli interact in the impression of landscapes. This paper examines the relationship between annoyance with sound from aircraft and annoyance with other area problems (e.g., careless bicycle riding, crowding, etc.), and how changes in noise exposure influence the perceived overall recreational quality of outdoor recreational areas. A panel study (telephone interviews) conducted before and after the relocation of Norway’s main airport in 1998 examined effects of decreased or increased noise exposure in nearby recreational areas (n = 591/455). Sound from aircraft annoyed the largest proportion of recreationists, except near the old airport after the change. The decrease in annoyance with sound from aircraft was accompanied by significant decreases in annoyance with most of the other area problems. Near the new airport annoyance with most factors beside sound from aircraft increased slightly, but not significantly. A relationship between aircraft noise annoyance and perceived overall recreational quality of the areas was found.