Exposure to long-term source-specific transportation noise and incident breast cancer: A pooled study of eight Nordic cohorts

The impacts of noise and air pollution on breast cancer risk in European and East Asian populations: Insights from genetic evidence

OBJECTIVES

Previous studies have reported associations of noise and air pollution with breast cancer (BC) risk, but the causality remains unclear. This study aimed to explore the effects of noise and air pollution on BC from a genetic perspective.

STUDY DESIGN

Genetic association study.

METHODS

We began our investigation by visualizing the development trends in this field through bibliometric analysis. Subsequently, we conducted Mendelian randomization analyses to assess the effects of noise (daytime and evening) and air pollution (NO2, NOx, PM2.5, PM2.5-10, and PM10) on BC. Genetic variants extracted from genome-wide association studies (GWAS) robustly associated with noise and air pollution were used as instrumental variables. The GWAS data for BC in European and East Asian populations were obtained from the Breast Cancer Association Consortium and the Biobank Japan, respectively.

RESULTS

The effects of noise and air pollution on BC are receiving increasing attention. In the European population, genetically predicted exposure to NO2 (OR: 1.9381; 95% CI: 1.2873-2.9180; P = 0.0015) and PM10 (OR: 1.4187; 95% CI: 1.0880-1.8500; P = 0.0098) were positively associated with overall BC risk. Subtype analyses showed that PM10 was significantly related to the risks of both ER+ (OR: 1.6165; 95% CI: 1.1778-2.2186; P = 0.0030) and ER- (OR: 1.6228; 95% CI: 1.0175-2.5881; P = 0.0421) BC. Additionally, NO2 only increased the risk of ER+ BC (OR: 1.7429; 95% CI: 1.0679-2.8444; P = 0.0262), but not ER- BC. In East Asians, genetically predicted NO2 was positively related to BC risk (OR: 1.1394; 95% CI: 1.0082-1.2877; P = 0.0366).

CONCLUSIONS

Our study gave new evidence from a genetic standpoint underscoring that improving the environmental quality of residential areas is conducive to reducing BC risk.

Road traffic noise and breast cancer: DNA methylation in four core circadian genes

BACKGROUND

Transportation noise has been linked with breast cancer, but existing literature is conflicting. One proposed mechanism is that transportation noise disrupts sleep and the circadian rhythm. We investigated the relationships between road traffic noise, DNA methylation in circadian rhythm genes, and breast cancer. We selected 610 female participants (318 breast cancer cases and 292 controls) enrolled into the Malmö, Diet, and Cancer cohort. DNA methylation of CpGs (N = 29) in regulatory regions of circadian rhythm genes (CRY1, BMAL1, CLOCK, and PER1) was assessed by pyrosequencing of DNA from lymphocytes collected at enrollment. To assess associations between modeled 5-year mean residential road traffic noise and differentially methylated CpG positions, we used linear regression models adjusting for potential confounders, including sociodemographics, shiftwork, and air pollution. Linear mixed effects models were used to evaluate road traffic noise and differentially methylated regions. Unconditional logistic regression was used to investigate CpG methylation and breast cancer.

RESULTS

We found that higher mean road traffic noise was associated with lower DNA methylation of three CRY1 CpGs (CpG1, CpG2, and CpG12) and three BMAL1 CpGs (CpG2, CpG6, and CpG7). Road traffic noise was also associated with differential methylation of CRY1 and BMAL1 promoters. In CRY1 CpG2 and CpG5 and in CLOCK CpG1, increasing levels of methylation tended to be associated with lower odds of breast cancer, with odds ratios (OR) of 0.88 (95% confidence interval (CI) 0.76-1.02), 0.84 (95% CI 0.74-0.96), and 0.80 (95% CI 0.68-0.94), respectively.

CONCLUSIONS

In summary, our data suggest that DNA hypomethylation in CRY1 and BMAL1 could be part of a causal chain from road traffic noise to breast cancer. This is consistent with the hypothesis that disruption of the circadian rhythm, e.g., from road traffic noise exposure, increases the risk of breast cancer. Since no prior studies have explored this association, it is essential to replicate our results.

Residential exposure to transportation noise and risk of incident atrial fibrillation: a pooled study of 11 prospective Nordic cohorts

Background

Transportation noise has been linked with cardiometabolic outcomes, yet whether it is a risk factor for atrial fibrillation (AF) remains inconclusive. We aimed to assess whether transportation noise was associated with AF in a large, pooled Nordic cohort.

Methods

We pooled data from 11 Nordic cohorts, totaling 161,115 participants. Based on address history from five years before baseline until end of follow-up, road, railway, and aircraft noise was estimated at a residential level. Incident AF was ascertained via linkage to nationwide patient registries. Cox proportional hazards models were utilized to estimate associations between running 5-year time-weighted mean transportation noise (Lden) and AF after adjusting for sociodemographics, lifestyle, and air pollution.

Findings

We identified 18,939 incident AF cases over a median follow-up of 19.6 years. Road traffic noise was associated with AF, with a hazard ratio (HR) and 95% confidence interval (CI) of 1.02 (1.00-1.04) per 10-dB of 5-year mean time-weighted exposure, which changed to 1.03 (1.01-1.06) when implementing a 53-dB cut-off. In effect modification analyses, the association for road traffic noise and AF appeared strongest in women and overweight and obese participants. Compared to exposures ≤40 dB, aircraft noise of 40.1-50 and > 50 dB were associated with HRs of 1.04 (0.93-1.16) and 1.12 (0.98-1.27), respectively. Railway noise was not associated with AF. We found a HR of 1.19 (1.02-1.40) among people exposed to noise from road (≥45 dB), railway (>40 dB), and aircraft (>40 dB) combined.

Interpretation

Road traffic noise, and possibly aircraft noise, may be associated with elevated risk of AF.

Funding

NordForsk.

Geospatial analysis for environmental noise mapping: A land use regression approach in a metropolitan city

Environmental noise can lead to adverse health outcomes. Understanding the spatial variability of environmental noise is crucial for mitigating potential health risks and developing influential urban strategies for reducing noise levels. This study aimed to measure noise levels and develop a land use regression (LUR) model to determine the spatial variability of environmental noise in Shiraz, Iran. A grid-based technique was used to establish 191 noise measurement sites (summer) across the city to generate the LUR model based on two noise metrics: Lden and Lnight. Leave-one-out cross-validation (LOOCV) and 38 additional measurement sites (winter) were used for the LUR model assessment. The mean values of Lden and Lnight during summer were 68.20 (±8.05) and 58.95 (±9.55), respectively, while during winter, the corresponding values were 69.46 (±5.46) and 58.81 (±6.79). The LUR models explained 67% and 65% of the spatial variability in Lden and Lnight, respectively. LOOCV analysis demonstrated R2 values of 0.64 and 0.61. Moreover, findings indicated mean absolute error (MAE) values of 3.96 dB(A) for Lden and 4.74 dB(A) for Lnight. Validation based on an additional set of 38 measurement sites revealed R2 values of 0.62 for both Lden and Lnight, with MAE of 2.78 and 3.31, respectively. In addition, the adjusted R2 values were 0.54 and 0.53. The results indicated no significant temporal variations between summer and winter. The results revealed that road-related variables significantly influenced noise levels. Moreover, the results indicated that Lden and Lnight levels were higher than the World Health Organization recommendations for exposure to road traffic noise. The results of our study showed that the LUR modeling approach based on geographical predictors is an effective tool for assessing changes in ambient noise levels in other cities in Iran and around the globe.

Road traffic noise exposure and its impact on health: evidence from animal and human studies-chronic stress, inflammation, and oxidative stress as key components of the complex downstream pathway underlying noise-induced non-auditory health effects

In heavily urbanized world saturated with environmental pollutants, road traffic noise stands out as a significant factor contributing to widespread public health issues. It contributes in the development of a diverse range of non-communicable diseases, such as cardiovascular diseases, metabolic dysregulation, cognitive impairment, and neurodegenerative disorders. Although the exact mechanisms behind these non-auditory health effects remain unclear, the noise reaction model centres on the stress response to noise. When exposed to noise, the body activates the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, leading to the secretion of stress hormones like catecholamines and cortisol. Prolonged exposure to noise-induced stress results in chronic inflammation and oxidative stress. This review underscores the role of inflammation and oxidative stress in the progression of noise-induced vascular dysfunction, disruption of the circadian rhythm, accelerated aging, neuroinflammation, and changes in microbiome. Additionally, our focus is on understanding the interconnected nature of these health outcomes: These interconnected factors create a cascade effect, contributing to the accumulation of multiple risk factors that ultimately lead to severe adverse health effects.

Noise and mental health: evidence, mechanisms, and consequences

The recognition of noise exposure as a prominent environmental determinant of public health has grown substantially. While recent years have yielded a wealth of evidence linking environmental noise exposure primarily to cardiovascular ailments, our understanding of the detrimental effects of noise on the brain and mental health outcomes remains limited. Despite being a nascent research area, an increasing body of compelling research and conclusive findings confirms that exposure to noise, particularly from sources such as traffic, can potentially impact the central nervous system. These harms of noise increase the susceptibility to mental health conditions such as depression, anxiety, suicide, and behavioral problems in children and adolescents. From a mechanistic perspective, several investigations propose direct adverse phenotypic changes in brain tissue by noise (e.g. neuroinflammation, cerebral oxidative stress), in addition to feedback signaling by remote organ damage, dysregulated immune cells, and impaired circadian rhythms, which may collectively contribute to noise-dependent impairment of mental health. This concise review linking noise exposure to mental health outcomes seeks to fill research gaps by assessing current findings from studies involving both humans and animals.