Postmenopausal breast cancer is associated with exposure to traffic-related air pollution in Montreal, Canada: a case-control study

Exposure to outdoor ambient air toxics and risk of breast cancer: The multiethnic cohort

BACKGROUND

A growing literature has reported associations between traffic-related air pollution and breast cancer, however there are fewer investigations into specific ambient agents and any putative risk of breast cancer development, particularly studies occurring in populations residing in higher pollution areas such as Los Angeles.

OBJECTIVES

To estimate breast cancer risks related to ambient air toxics exposure at residential addresses.

METHODS

We examined the relationships between ambient air toxics and breast cancer risk in the Multiethnic Cohort among 48,665 California female participants followed for cancer from 2003 through 2013. We obtained exposure data on chemicals acting as endocrine disruptors or mammary gland carcinogens from the National-Scale Air Toxics Assessment. Cox proportional hazards models were used to estimate breast cancer risk per one interquartile range (IQR) increase in air toxics exposure lagged by 5-years. Stratified analyses were conducted by race, ethnicity, and hormone receptor types.

RESULTS

Among all women, increased risks of invasive breast cancer were observed with toxicants related to industries [1,1,2,2-tetrachloroethane (hazard ratio [HR] = 4.22, 95% confidence interval [95% CI] 3.18-5.60), ethylene dichloride (HR = 2.81, 95% CI 2.20-3.59), and vinyl chloride (HR = 2.27, 95% CI 1.81, 2.85); these 3 agents were correlated (r2 = 0.45-0.77)]. Agents related to gasoline production or combustion were related to increased breast cancer risk [benzene (HR = 1.32, 95% CI 1.24, 1.41), ethylbenzene (HR = 1.20, 95% CI 1.13-1.28), toluene (HR = 1.29, 95% CI 1.20-1.38), naphthalene (HR = 1.11, 95% CI 1.02-2.22), acrolein (HR = 2.26, 95% CI 1.92, 2.65)]. Higher hazard ratios were observed in African Americans and Whites compared to other racial and ethnic groups (p-heterogeneity <0.05 for traffic-related air toxics, acrolein, and vinyl acetate).

CONCLUSIONS

Our findings suggest that specific toxic air pollutants may be associated with increase breast cancer risk.

Assessing the Global Impact of Ambient Air Pollution on Cancer Incidence and Mortality: A Comprehensive Meta-Analysis

PURPOSE

This study aims to examine the association between exposure to major ambient air pollutants and the incidence and mortality of lung cancer and some nonlung cancers.

METHODS

This meta-analysis used PubMed and EMBASE databases to access published studies that met the eligibility criteria. Primary analysis investigated the association between exposure to air pollutants and cancer incidence and mortality. Study quality was assessed using the Newcastle Ottawa Scale. Meta-analysis was conducted using R software.

RESULTS

The meta-analysis included 61 studies, of which 53 were cohort studies and eight were case-control studies. Particulate matter 2.5 mm or less in diameter (PM2.5) was the exposure pollutant in half (55.5%), and lung cancer was the most frequently studied cancer in 59% of the studies. A pooled analysis of exposure reported in cohort and case-control studies and cancer incidence demonstrated a significant relationship (relative risk [RR], 1.04 [95% CI, 1.02 to 1.05]; I2, 88.93%; P < .05). A significant association was observed between exposure to pollutants such as PM2.5 (RR, 1.08 [95% CI, 1.04 to 1.12]; I2, 68.52%) and nitrogen dioxide (NO2) (RR, 1.03 [95% CI, 1.01 to 1.05]; I2, 73.52%) and lung cancer incidence. The relationship between exposure to the air pollutants and cancer mortality demonstrated a significant relationship (RR, 1.08 [95% CI, 1.07 to 1.10]; I2, 94.77%; P < .001). Among the four pollutants, PM2.5 (RR, 1.15 [95% CI, 1.08 to 1.22]; I2, 95.33%) and NO2 (RR, 1.05 [95% CI, 1.02 to 1.08]; I2, 89.98%) were associated with lung cancer mortality.

CONCLUSION

The study confirms the association between air pollution exposure and lung cancer incidence and mortality. The meta-analysis results could contribute to community cancer prevention and diagnosis and help inform stakeholders and policymakers in decision making.

Outdoor air pollution exposure and uterine cancer incidence in the sister study

BACKGROUND

Outdoor air pollution is a ubiquitous exposure that includes endocrine-disrupting and carcinogenic compounds that may contribute to the risk of hormone-sensitive outcomes such as uterine cancer. However, there is limited evidence about the relationship between outdoor air pollution and uterine cancer incidence.

METHODS

We investigated the associations of residential exposure to particulate matter less than 2.5 µm in diameter (PM2.5) and nitrogen dioxide (NO2) with uterine cancer among 33,417 Sister Study participants with an intact uterus at baseline (2003-2009). Annual average air pollutant concentrations were estimated at participants' geocoded primary residential address(es) using validated spatiotemporal models. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between time-varying 12-month PM2.5 (µg/m3) and NO2 (ppb) averages and uterine cancer incidence.

RESULTS

Over a median follow-up period of 9.8 years, 319 incident uterine cancer cases were identified. A 5-ppb increase in NO2 was associated with a 23% higher incidence of uterine cancer (HR = 1.23, 95% CI 1.04-1.46), especially among participants living in urban areas (HR = 1.53, 95% CI: 1.13-2.07). However, PM2.5 was not associated with increased uterine cancer incidence.

CONCLUSION

In this large U.S. cohort, NO2, a marker of vehicular traffic exposure, was associated with a higher incidence of uterine cancer. These findings expand the scope of health effects associated with air pollution, supporting the need for policy and other interventions designed to reduce air pollutant exposure.

Associations of air pollution and greenness with global burden of breast cancer: an ecological study

Despite the significance of the associations of air pollution and greenness with the risk of breast cancer, this topic has not been investigated on a global scale. We conducted an ecological study using 7 years of data from 162 countries. Disability-adjusted life years (DALYs) and incidence data were used to represent the breast cancer disease burden. Particulate matter with a diameter < 2.5 μm (PM2.5), ozone (O3), nitrogen dioxide (NO2), and the normalized difference vegetation index (NDVI) were adopted as our exposures. We employed generalized linear mixed models to explore the relationship between air pollution and greenness on breast cancer disease burden. The rate ratio (RR) and its 95% confidence interval (CI) indicate the effect size. There is a positive association between air pollution and the burden of breast cancer disease. Contrarily, per interquartile range increment in NDVI was negatively associated with DALYs and incidence. In terms of air pollutants and breast cancer, NDVI seems to have a significant influence on the relationship between these two conditions. A higher amount of greenness helps to alleviate the negative association of air pollution on breast cancer. PM2.5 and O3 play a mediating role in the relationship between greenness and breast cancer disease burden. In areas with higher levels of greenness, there is a possibility that the inverse association between air pollutants and the burden of breast cancer may be influenced.

Additive effects of 10-year exposures to PM2.5 and NO2 and primary cancer incidence in American older adults

Epidemiologic evidence on the relationships between air pollution and the risks of primary cancers other than lung cancer remained largely lacking. We aimed to examine associations of 10-year exposures to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) with risks of breast, prostate, colorectal, and endometrial cancers.

Methods

For each cancer, we constructed a separate cohort among the national Medicare beneficiaries during 2000 to 2016. We simultaneously examined the additive associations of six exposures, namely, moving average exposures to PM2.5 and NO2 over the year of diagnosis and previous 2 years, previous 3 to 5 years, and previous 6 to 10 years, with the risk of first cancer diagnosis after 10 years of follow-up, during which there was no cancer diagnosis.

Results

The cohorts included 2.2 to 6.5 million subjects for different cancers. Exposures to PM2.5 and NO2 were associated with increased risks of colorectal and prostate cancers but were not associated with endometrial cancer risk. NO2 was associated with a decreased risk of breast cancer, while the association for PM2.5 remained inconclusive. At exposure levels below the newly updated World Health Organization Air Quality Guideline, we observed substantially larger associations between most exposures and the risks of all cancers, which were translated to hundreds to thousands new cancer cases per year within the cohort per unit increase in each exposure.

Conclusions

These findings suggested substantial cancer burden was associated with exposures to PM2.5 and NO2, emphasizing the urgent need for strategies to mitigate air pollution levels.

Association of air pollution with postmenopausal breast cancer risk in UK Biobank

BACKGROUND

We investigated the association of several air pollution measures with postmenopausal breast cancer (BCa) risk.

METHODS

This study included 155,235 postmenopausal women (of which 6146 with BCa) from UK Biobank. Cancer diagnoses were ascertained through the linkage to the UK National Health Service Central Registers. Annual exposure averages were available from 2005, 2006, 2007, and 2010 for NO2, from 2007 and 2010 for PM10, and from 2010 for PM2.5, NOX, PM2.5-10 and PM2.5 absorbance. Information on BCa risk factors was collected at baseline. Cox proportional hazards regression was used to evaluate the associations of year-specific and cumulative average exposures with BCa risk, overall and with 2-year exposure lag, while adjusting for BCa risk factors.

RESULTS

PM10 in 2007 and cumulative average PM10 were positively associated with BCa risk (2007 PM10: Hazard ratio [HR] per 10 µg/m3 = 1.18, 95% CI 1.08, 1.29; cumulative average PM10: HR per 10 µg/m3 = 1.99, 95% CI 1.75, 2.27). Compared to women with low exposure, women with higher 2007 PM10 and cumulative average PM10 had greater BCa risk (4th vs. 1st quartile HR = 1.15, 95% CI 1.07, 1.24, p-trend = 0.001 and HR = 1.35, 95% CI 1.25, 1.44, p-trend < 0.0001, respectively). No significant associations were found for any other exposure measures. In the analysis with 2-year exposure lag, both 2007 PM 10 and cumulative average PM10 were positively associated with BCa risk (4th vs. 1st quartile HR = 1.19, 95% CI 1.10, 1.28 and HR = 1.29, 95% CI 1.19, 1.39, respectively).

CONCLUSION

Our findings suggest a positive association of 2007 PM10 and cumulative average PM10 with postmenopausal BCa risk.

Traffic-Related Air Pollution and Risk of Lung, Breast, and Urinary Tract Cancer in Halifax, Nova Scotia

OBJECTIVES

We assessed the association of traffic-related air pollution (TRAP) with the incidence of lung, breast, and urinary tract cancer in Halifax, Nova Scotia.

METHODS

Our case-control study included 2315 cancers and 8501 age-sex-matched controls. Land-use regression was used to estimate TRAP concentrations. Logistic regression was used to assess cancer risk in relation to TRAP, adjusting for community social and material deprivation.

RESULTS

There was no association between the risk of lung, breast, or urinary tract cancer in relation to TRAP. Lung cancer risk was significantly increased in the most deprived communities, whereas breast cancer risk was highest in the least deprived communities.

CONCLUSIONS

In a city characterized by low levels of ambient air pollution, there was no evidence of a linear increased lung, breast, or urinary tract cancer risk in relation to TRAP.

Spatial pattern and environmental drivers of breast cancer incidence in Chinese women

Breast cancer (BC) had the highest incidence of all cancers in Chinese women. However, studies on spatial pattern and environmental drivers of BC were still lacked as they were either limited in a small area or few considered the comprehensive impact of multiple risk factors. In this study, we firstly performed spatial visualization and the spatial autocorrelation analysis based on Chinese women breast cancer incidence (BCI) data of 2012-2016. Then, we explored the environmental drivers related to BC by applying univariate correlation analysis and geographical detector model. We found that the BC high-high clusters were mainly distributed in the eastern and central regions, such as Liaoning, Hebei, Shandong, Henan, and Anhui Provinces. The BCI in Shenzhen was significantly higher than other prefectures. Urbanization rate (UR), per capita GDP (PGDP), average years of school attainment (AYSA), and average annual wind speed (WIND) had higher explanatory power on spatial variability of the BCI. PM₁₀, NO₂, and PGDP had significant nonlinear enhanced effect on other factors. Besides, normalized difference vegetation index (NDVI) was negatively associated with BCI. Therefore, high socioeconomic status, serious air pollution, high wind speed, and low vegetation cover were the risk factors for BC. Our study may able to provide evidence for BC etiology research and precise identification of areas requiring focused screening.

Spatial patterns and the associated factors for breast cancer hospitalization in the rural population of Fujian Province, China

BACKGROUND

Despite the known increasing incidence of breast cancer in China, evidence on the spatial pattern of hospitalization for breast cancer is scarce. This study aimed to describe the disparity of breast cancer hospitalization in the rural population of Southeast China and to explore the impacts of socioeconomic factors and heavy metal pollution in soil.

METHODS

This study was conducted using the New Rural Cooperative Medical Scheme (NRCMS) claims data covering 20.9 million rural residents from 73 counties in Southeast China during 2015-2016. The associations between breast cancer hospitalization and socioeconomic factors and soil heavy metal pollutants were evaluated with quasi-Poisson regression models and geographically weighted Poisson regressions (GWPR).

RESULTS

The annual hospitalization rate for breast cancer was 101.40/100,000 in the studied area and the rate varied across different counties. Overall, hospitalization for breast cancer was associated with road density (β = 0.43, P = 0.02), urbanization (β = 0.02, P = 0.002) and soil cadmium (Cd) pollution (β = 0.01, P = 0.02). In the GWPR model, a stronger spatial association of Cd, road density and breast cancer hospitalization was found in the northeast regions of the study area while breast cancer hospitalization was mainly related to urbanization in the western regions.

CONCLUSIONS

Soil Cd pollution, road density, and urbanization were associated with breast cancer hospitalization in different regions. Findings in this study might provide valuable information for healthcare policies and intervention strategies for breast cancer.

Traffic-Related Air Pollution and Breast Cancer Risk: A Systematic Review and Meta-Analysis of Observational Studies

Current evidence of an association of breast cancer (BC) risk with air pollution exposure, in particular from traffic exhaust, remains inconclusive, and the exposure assessment methodologies are heterogeneous. This study aimed to conduct a systematic review and meta-analysis on the association between traffic-related air pollution (TRAP) and BC incidence (PROSPERO CRD42021286774). We systematically reviewed observational studies assessing exposure to TRAP and BC risk published until June 2022, available on Medline/PubMed and Web of Science databases. Studies using models for assessing exposure to traffic-related air pollutants or using exposure proxies (including traffic density, distance to road, etc.) were eligible for inclusion. A random-effects meta-analysis of studies investigating the association between NO₂/NO_x exposure and BC risk was conducted. Overall, 21 studies meeting the inclusion criteria were included (seven case-control, one nested case-control, 13 cohort studies); 13 studies (five case-control, eight cohort) provided data for inclusion in the meta-analyses. Individual studies provided little evidence of an association between TRAP and BC risk; exposure assessment methods and time periods of traffic emissions were different. The meta-estimate on NO₂ exposure indicated a positive association (pooled relative risk per 10 µg/m³ of NO₂: 1.015; 95% confidence interval, CI: 1.003; 1.028). No association between NO_x exposure and BC was found (three studies). Although there was limited evidence of an association for TRAP estimated with proxies, the meta-analysis showed a significant association between NO₂ exposure, a common TRAP pollutant marker, and BC risk, yet with a small effect size. Our findings provide additional support for air pollution carcinogenicity.

Spatial distribution and influencing factors of thyroid cancer hospitalization rate among rural residents in Fujian Province, China from 2012 to 2016

This study aimed to explore the spatial distribution and influencing factors of thyroid cancer hospitalization rates in Fujian Province from 2012 to 2016. Hospitalization reimbursement records for thyroid cancer were obtained from 2025 hospitals in Fujian Province from 2012 to 2016. The Moran's I method was used for spatial autocorrelation analysis and to further draw a spatial cluster map in Fujian. Geographic detectors were used to explore the effect of risk factors on spatial heterogeneity of inpatient service utilization for thyroid cancer. The study showed that there was obvious temporal and spatial heterogeneity in the utilization rate of inpatient services for thyroid cancer in Fujian Province, which were mainly concentrated in Fuzhou, with Lianjiang County as the center, and the gathering area involves 26 counties and cities. Among a variety of environmental factors, air quality index (AQI) (q = 0.481), carbon sequestration (q = 0.161), and carbon emissions (q = 0.155) were the main factors affecting the hospitalization rates. AQI and carbon emissions were generally positively correlated with hospitalization rates, and carbon sequestration was negatively correlated. After the interaction of the two factors, the interpretation of the hospitalization rate was enhanced. The obvious spatial heterogeneity will help the relevant departments to adjust measures to local conditions and allocate medical resources rationally to ease the pressure of seeking medical attention in high-demand areas.

Long-term exposure to nitrogen dioxide air pollution and breast cancer risk: A nested case-control within the French E3N cohort study

Nitrogen dioxide (NO₂) is an important air pollutant due to its adverse effects on human health. Yet, current evidence on the association between NO₂ and the risk of breast cancer lacks consistency. In this study, we investigated the association between long-term exposure to NO₂ and breast cancer risk in the French E3N cohort study. Association of breast cancer risk with NO₂ exposure was assessed in a nested case-control study within the French E3N cohort including 5222 breast cancer cases identified over the 1990-2011 follow-up period and 5222 matched controls. Annual mean concentrations of NO₂ at participants' residential addresses for each year from recruitment 1990 through 2011, were estimated using a land use regression (LUR) model. Multivariable conditional logistic regression models were used to compute odds ratios (ORs) and their 95% confidence intervals (CIs). Additional analyses were performed using NO₂ concentrations estimated by CHIMERE, a chemistry transport model. Overall, the mean NO₂ exposure was associated with an increased risk of breast cancer. In all women, for each interquartile range (IQR) increase in NO₂ levels (LUR: 17.8 μg/m³), the OR of the model adjusted for confounders was 1.09 (95% CI: 1.01-1.18). The corresponding OR in the fully adjusted model (additionally adjusted for established breast cancer risk factors) was 1.07 (95% CI: 0.98-1.15). By menopausal status, results for postmenopausal women were comparable to those for all women, while no association was observed among premenopausal women. By hormone receptor status, the OR of estrogen receptor positive breast cancer = 1.07 (95% CI: 0.97-1.19) in the fully adjusted model. Additional analyses using the CHIMERE model showed slight differences in ORs estimates. The results of this study indicate an increased risk of breast cancer associated with long-term exposure to NO₂ air pollution. Observing comparable effects of NO₂ exposure estimated by two different models, reinforces these findings.

Multivariate analysis in data science for the geospatial distribution of the breast cancer mortality rate in Colombia

This research is framed in the area of biomathematics and contributes to the epidemiological surveillance entities in Colombia to clarify how breast cancer mortality rate (BCM) is spatially distributed in relation to the forest area index (FA) and circulating vehicle index (CV). In this regard, the World Health Organization has highlighted the scarce generation of knowledge that relates mortality from tumor diseases to environmental factors. Quantitative methods based on geospatial data science are used with cross-sectional information from the 2018 census; it's found that the BCM in Colombia is not spatially randomly distributed, but follows cluster aggregation patterns. Under multivariate modeling methods, the research provides sufficient statistical evidence in terms of not rejecting the hypothesis that if a spatial unit has high FA and low CV, then it has significant advantages in terms of lower BCM.

Residence near industrial complex and cancer incidence: A registry-based cohort of 1,022,637 participants with a follow-up of 21 years, Israel

BACKGROUND

Industrial complex (IC) residence is associated with higher cancer incidence in adults and children. However, the effect on young adults and the residence duration are not well described. Since the beginning of the 20th century, the Haifa bay area (HBA) has a major IC area with petrochemical industry complex and many other industries. The objectives of the current study were to estimate the association between IC residence and cancer incidence and to evaluate the effect of the residence duration.

METHODS

This study is a registry-based cohort (N = 1,022,637) with a follow-up of 21 years. Cox regression models were used to evaluate the associations (hazards ratios (HR) and its 95% confidence intervals (CIs)) between HBA residence and incidence of all cancer sites (n = 62,049) and for site-specific cancer types including: lung cancer (n = 5398), bladder cancer (n = 3790), breast cancer (n = 11,310), prostate cancer (n = 6389) skin cancer (n = 4651), pancreatic cancer (n = 2144) and colorectal cancer (n = 8675). We evaluated the effect of the duration of exposure as categories of 7 years for those with 15 years of follow-up.

RESULTS

IC residence was associated with higher risk for all cancer sites (HR:1.09, 95% CI: 1.06-1.12), for site-specific cancer incidence including: lung cancer (HR:1.14, 95% CI: 1.04-1.23), bladder cancer (HR:1.11, 95% CI: 1.01-1.23), breast cancer (HR:1.04, 95% CI: 0.98-1.10), prostate cancer (HR:1.07, 95% CI: 0.99-1.16), skin cancer (HR:1.22, 95% CI: 1.12-1.33) and colorectal cancer (HR:1.10, 95%CI: 1.03-1.17). Similar risk was also observed among young adults (HR: 1.10, 95% CI: 1.00-1.20). In the analyses for the duration of exposure, IC residence was associated with higher risk for all cancer site for the longest residence duration (15-21 years: HR: 1.08, 95% CI: 1.04-1.13).

CONCLUSIONS

Harmful associations were found between IC residence and incidence of all cancer sites and site-specific cancers types. Our findings add to the limited evidence of associations between IC residence and cancer in young adults.

Air pollution and green spaces in relation to breast cancer risk among pre and postmenopausal women: A mega cohort from Catalonia

BACKGROUND

The association between air pollution and green spaces with breast cancer risk stratified by menopausal status has not been frequently investigated despite its importance given the different impact of risk factors on breast cancer risk depending on menopausal status.

OBJECTIVES

To study the association between air pollution, green spaces and pre and postmenopausal breast cancer risk.

METHODS

We conducted a population-based cohort study using electronic primary care records in Catalonia. We included women aged 17-85 years free of cancer at study entry between 2009 and 2017. Our exposures were particulate matter <2.5 μm (PM_2.5) & <10 μm (PM₁₀), nitrogen dioxide (NO₂), normalized difference vegetation index (NDVI), and percentage of green spaces estimated at the census tract level. Breast cancer was identified with ICD-10 code C50. We estimated cause-specific hazard ratios (HR) for the relationship between each individual exposure and pre and postmenopausal breast cancer risk, using linear and non-linear models.

RESULTS

Of the 1,054,180 pre and 744,658 postmenopausal women followed for a median of 10 years, 6,126 and 17,858 developed breast cancer, respectively. Among premenopausal women, only very high levels of PM₁₀ (≥46 μg/m³) were associated with increased cancer risk (compared to lower levels) in non-linear models. Among postmenopausal women, an interquartile range increase in PM_2.5 (HR:1.03; 95%CI:1.01-1.04), PM₁₀ (1.03; 1.01-1.05), and NO₂ (1.05; 1.02-1.08) were associated with higher cancer risk. NDVI was negatively associated with decreased cancer risk only among postmenopausal women who did not change residence during follow-up (0.84; 0.71-0.99) or who were followed for at least three years (0.82; 0.69-0.98).

DISCUSSION

Living in areas with high concentrations of PM_2.5, PM₁₀, and NO₂ increases breast cancer risk in postmenopausal women while long-term exposure to green spaces may decrease this risk. Only very high concentrations of PM₁₀ increase breast cancer risk in premenopausal women.

The association between outdoor air pollution and lung cancer risk in seven eastern metropolises of China: Trends in 2006-2014 and sex differences

There is a positive association between air pollution and lung cancer burden. This study aims to identify and examine lung cancer risks and mortality burdens associated with air pollutants, including PM₁₀, NO₂ and SO₂, in seven eastern metropolises of China. The study population comprised a population from seven eastern metropolises of China. The yearly average values (YAV, μg/m³) of the PM₁₀, NO₂ and SO₂ levels were extracted from China Statistical Yearbook (CSYB) for each selected city from 2006 to 2014. Data collected in the China Cancer Registry Annual Report (CCRAR) provide lung cancer incidence and mortality information. A two-level normal random intercept regression model was adopted to analyze the association between the lung cancer rates and individual air pollutant concentration within a five-year moving window of past exposure. The yearly average values of PM10, SO2 and NO2 significantly decreased from 2006 to 2014. Consistently, the male age-adjusted incidence rate (MAIR) and male age-adjusted mortality rate (MAMR) decreased significantly from 2006 to 2014.Air pollutants have a lag effect on lung cancer incidence and mortality for 2-3 years. NO2 has the significant association with MAIR (RR=1.57, 95% CI: 1.19-2.05, p=0.002), MAMR (RR=1.70, 95% CI: 1.32-2.18, p=0.0002) and female age-adjusted mortality rate (FAMR) (RR=1.27, 95% CI: 1.08-1.49, p=0.003). Our findings suggested that air pollutants may be related to the occurrence and mortality of lung cancer. NO2 was significantly associated with the risk of lung cancer, followed by SO2. Air pollutants have the strongest lag effect on the incidence and mortality of lung cancer within 2-3 years.

Spatial modeling of ambient concentrations of volatile organic compounds in Montreal, Canada

Volatile organic compounds (VOCs) are components of the complex mixture of air pollutants within cities and can cause various adverse health effects. Therefore, it is necessary to understand their spatial distribution for exposure assessment in epidemiological studies.

An Evaluation of Risk Ratios on Physical and Mental Health Correlations due to Increases in Ambient Nitrogen Oxide (NOx) Concentrations

Nitrogen oxides (NOx) are gaseous pollutants contributing to pollution in their primary form and are also involved in reactions forming ground-level ozone and fine particulate matter. Thus, NOx is of great interest for targeted pollution reduction because of this cascade effect. Primary emissions originate from fossil fuel combustion making NOx a common outdoor and indoor air pollutant. Numerous studies documenting the observed physical health impacts of NOx were reviewed and, where available, were summarized using risk ratios. More recently, the literature has shifted to focus on the mental health implications of NOx exposure, and a review of the current literature found five main categories of mental health-related conditions with respect to NOx exposure: common mental health disorders, sleep, anxiety, depression, and suicide. All the physical and mental health effects with available risk ratios were organized in order of increasing risk. Mental health concerns emerged as those most influenced by NOx exposure, with physical health impacts, such as asthma, only beginning to surface as the fourth highest risk. Mental health conditions occupied seven of the top ten highest risk health ailments. The results summarized in this narrative review show that there are clear positive correlations between NOx and negative physical and mental health manifestations, thus strengthening the argument in support of the reduction in ambient NOx levels.

An Investigation into Which Methods Best Explain Children’s Exposure to Traffic-Related Air Pollution

There have been several methods employed to quantify individual-level exposure to ambient traffic-related air pollutants (TRAP). These include an individual’s residential proximity to roads, measurement of individual pollutants as surrogates or markers, as well as dispersion and land use regression (LUR) models. Hopanes are organic compounds still commonly found on ambient particulate matter and are specific markers of combustion engine primary emissions, but they have not been previously used in personal exposure studies. In this paper, children’s personal exposures to TRAP were evaluated using hopanes determined from weekly integrated filters collected as part of a personal exposure study in Windsor, Canada. These hopane measurements were used to evaluate how well other commonly used proxies of exposure to TRAP performed. Several of the LUR exposure estimates for a range of air pollutants were associated with the children’s summer personal hopane exposures (r = 0.41–0.74). However, all personal hopane exposures in summer were more strongly associated with the length of major roadways within 500 m of their homes. In contrast, metrics of major roadways and LUR estimates were poorly correlated with any winter personal hopanes. Our findings suggest that available TRAP exposure indicators have the potential for exposure misclassification in winter vs. summer and more so for LUR than for metrics of major road density. As such, limitations are evident when using traditional proxy methods for assigning traffic exposures and these may be especially important when attempting to assign exposures for children’s key growth and developmental windows. If long-term chronic exposures are being estimated, our data suggest that measures of major road lengths in proximity to homes are a more-specific approach for assigning personal TRAP exposures.

Role of the Synergistic Interactions of Environmental Pollutants in the Development of Cancer

There is a growing awareness that the large number of environmental pollutants we are exposed to on a daily basis are causing major health problems. Compared to traditional studies that focus on individual pollutants, there are relatively few studies on how pollutants mixtures interact. Several studies have reported a relationship between environmental pollutants and the development of cancer, even when pollutant levels are below toxicity reference values. The possibility of synergistic interactions between different pollutants could explain how even low concentrations can cause major health problems. These intricate that molecular interactions can occur through a wide variety of mechanisms, and our understanding of the physiological effects of mixtures is still limited. The purpose of this paper is to discuss recent reports that address possible synergistic interactions between different types of environmental pollutants that could promote cancer development. Our literature studies suggest that key biological pathways are frequently implicated in such processes. These include increased production of reactive oxygen species, activation by cytochrome P450, and aryl hydrocarbon receptor signaling, among others. We discuss the need to understand individual pathological vulnerability not only in relation to basic genetics and gene expression, but also in terms of measurable exposure to contaminants. We also mention the need for significant improvements in future studies using a multitude of disciplines, such as the development of high-throughput study models, better tools for quantifying pollutants in cancer patients, innovative pharmacological and toxicological studies, and high-efficiency computer analysis, which allow us to analyze the molecular mechanisms of mixtures.

Emulating Near-Roadway Exposure to Traffic-Related Air Pollution via Real-Time Emissions from a Major Freeway Tunnel System

Epidemiological and toxicological studies continue to demonstrate correlative and causal relationships between exposure to traffic-related air pollution and various metrics of adverse pulmonary, cardiovascular, and neurological health effects. The key challenge for in vivo studies is replicating real-world, near-roadway exposure dynamics in laboratory animal models that mimic true human exposures. The advantage of animal models is the accelerated time scales to show statistically significant physiological and/or behavioral response. This work describes a novel exposure facility adjacent to a major freeway tunnel system that provides a platform for real-time chronic exposure studies. The primary conclusion is that particulate matter (PM) concentrations at this facility are routinely well below the National Ambient Air Quality Standards (NAAQS), but studies completed to date still demonstrate significant neurological and cardiovascular effects. Internal combustion engines produce large numbers of ultrafine particles that contribute negligible mass to the atmosphere relative to NAAQS regulated PM2.5 but have high surface area and mobility in the body. It is posited here that current federal and state air quality standards are thus insufficient to fully protect human health, most notably the developing and aging brain, due to regulatory gaps for ultrafine particles.

The association between the incidence of post-menopausal breast cancer and residential greenness

BACKGROUND

There is little data as to whether exposure to residential greenness is associated with the incidence of breast cancer. Lack of physical activity and obesity are two of the accepted risk factors for postmenopausal breast cancer and living near green areas may contribute to an active lifestyle and maintaining a normal body mass index and, consequently, residential greenness may be associated with lower incidence rates.

OBJECTIVES

The objective of this study was to determine whether there was an association between past exposure to residential greenness and the incidence of invasive postmenopausal breast cancer among Canadian women living in Montreal, Quebec, in the mid-2000s.

METHODS

We conducted a population-based, case-control study of incident postmenopausal breast cancer in Montreal, Canada, and herein we show analyses by level of greenness surrounding participants' homes. Incident cases were identified between 2008 and 2011 from all but one hospital that treated breast cancer in the Montreal area. Population controls were identified from provincial electoral lists of Montreal residents and frequency-matched to cases on age. Residential greenness was estimated using the maximum daily normalized difference vegetation index averaged over the growing season ("maximum NDVI"). Maximum NDVI was assigned at the home address of recruitment for the years 1992-1998 (about 15 years before diagnosis), and we measured subjects' personal information, exposure to NO₂ and ultrafine particles, and area-wide variables to control for potential confounding effects. Odds ratios (OR) and 95% confidence intervals (CI) for breast cancer associated with residential greenness were estimated using logistic regression models adjusting for various combinations of potential confounders. We assessed the functional form of maximum NDVI using natural cubic splines.

RESULTS

We found that the response functions between incident postmenopausal breast cancer and maximum NDVI were consistent with linearity. The age-adjusted and fully-adjusted ORs, per increase in the interquartile range (IQR=0.13) of maximum NDVI measured with a 250 m buffer around residences, were 0.95 (95%CI: 0.86-1.04) and 1.00 (95%CI: 0.84-1.11), respectively. For maximum NDVI measured using a 1000 m buffer (IQR=0.05), these were 0.98 (95%CI: 0.94-1.02) and 0.99 (95%CI: 0.95-1.03), respectively.

CONCLUSIONS

Our findings suggest that exposure to NDVI evaluated where participants were interviewed is not associated with the risk of incident postmenopausal breast cancer.

Association between long-term ambient air pollution exposure and the risk of breast cancer: a systematic review and meta-analysis

Breast cancer is a complex and multifactorial disease which stems significantly from both environmental and genetic factors. A growing number of epidemiological studies have suggested that ambient air pollution (AAP) exposure may play an important role in breast cancer development. However, no consistency has been reached concerning whether high levels of air pollutant exposure were related to increased breast cancer risk among the current evidence. To further clarify such association of long-term AAP exposure with risk of breast cancer, a systematic review and meta-analysis of available evidence was performed. An extensive literature search in 3 academic databases was conducted before March 10, 2020. The risk of bias (RoB) for each individual study was evaluated with a domain-based assessment tool, developed by the National Toxicology Program/Office of Health Assessment and Translation (NTP/OHAT). Meta-estimates for air pollutant-breast cancer combinations were calculated for a standardized increment in exposure by random-effect models. The confidence level in the body of evidence and the certainty of evidence was also assessed for each air pollutant-breast cancer combination. The initial search identified 5446 studies, and 18 of them were eligible. The pooled analysis found an increased risk of breast cancer was associated with an increase in each 10 μg/m³ in nitrogen dioxide (NO₂) exposure (hazard ratio (HR) = 1.02, 95% confidence interval (CI) = 1.01, 1.04), while particulate matter with aerodynamic diameters ≤ 2.5 μm and 10 μm (PM_2.5, PM₁₀) revealed no statistically significant associations with breast cancer risk. Our evaluation on the certainty of evidence indicates that there was a "moderate level of evidence" in the body of evidence for an association of NO₂ exposure with an increased breast cancer risk and an "inadequate level of evidence" in the body of evidence for an association of PM_2.5 and PM₁₀ exposure with an increased breast cancer risk. Our study suggests long-term exposure to NO₂ is related to an increased risk of breast cancer. However, in consideration of the limitations, further studies, especially performed in developing countries, with improvements in exposure assessment, outcome ascertainment, and confounder adjustment, are needed to draw a definite evidence of a causal relationship.

Breast cancer risk in relation to ambient concentrations of nitrogen dioxide and particulate matter: results of a population-based case-control study corrected for potential selection bias (the CECILE study)

BACKGROUND

There is only scant evidence that air pollution increases the risk of breast cancer.

OBJECTIVES

We investigated this relationship for three air pollutants: nitrogen dioxide (NO₂) and particulate matter with an aerodynamical diameter below 10 µm (PM₁₀) and 2.5 µm (PM_2.5).

METHODS

We conducted a population-based case-control study on breast cancer in two French départements, including 1,229 women diagnosed with breast cancer in 2005-2007 and 1,316 control women frequency-matched on age. Concentrations of NO₂, PM₁₀ and PM_2.5 at participants' addresses occupied during the last 10 years were assessed using a chemistry transport model. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using multivariable logistic regression models where each woman was assigned a weight depending on her probability of selection into the study.

RESULTS

The OR for breast cancer per 10-µg/m³ increase in NO₂ was 1.11 (95% CI, 0.98, 1.26), and 1.41 (95% CI 1.07, 1.86) in the highest exposure quintile (Q5), compared to the first. The ORs per 10-µg/m³ NO₂ did not markedly differ between pre- (OR 1.09, 95% CI 0.89, 1.35)) and post-menopausal women (OR 1.14, 95% CI 0.97, 1.33)), but the OR was substantially higher for hormone-receptor positive (ER+/PR+) breast tumor subtypes (OR 1.15, 95% CI 1.00, 1.31) than for ER-/PR- tumors (OR 0.95, 95% CI 0.72, 1.26). Breast cancer risk was not associated with either PM₁₀ (OR per 1 µg/m³ 1.01, 95% CI, 0.96, 1.06) or PM_2.5 (OR per 1 µg/m³ 1.02, 95% CI 0.95, 1.08), regardless of the menopausal status or of the breast tumor subtype.

DISCUSSION

Our study provides evidence that NO₂ exposure, a marker of traffic-related air pollutants, may be associated with an increased risk of breast cancer, particularly ER+/PR+ tumors.

Spatial interaction between breast cancer and environmental pollution in the Monterrey Metropolitan Area

This research examines the spatial structure of a sample of breast cancer (BC) cases and their spatial interaction with contaminated areas in the Monterrey Metropolitan Area (MMA). By applying spatial statistical techniques that treat the space as a continuum, degrees of spatial concentration were determined for the different study groups, highlighting their concentration pattern. The results indicate that 65 percent of the BC sample had exposure to more than 56 points of PM10. Likewise, spatial clusters of BC cases of up to 39 cases were identified within a radius of 3.5 km, interacting spatially with environmental contamination sources, particularly with refineries, food processing plants, cement, and metals. This study can serve as a platform for other clinical research by identifying geographic clusters that can help focus health policy efforts.

Endocrine disrupting chemicals and breast cancer cells

Many hundreds of endocrine disrupting chemicals (EDCs) have been measured as entering human breast tissue from a range of environmental sources, and this review focuses on discussion of mechanisms by which such EDCs may be contributing to the globally rising incidence of breast cancer. Many of the distinguishing features of breast cancer may be accounted for by EDC exposure, including, but not limited to, the fact that many EDCs possess estrogenic activity and exposure to estrogen is a main risk factor for breast cancer. Studies of the actions of EDCs in human breast cancer cells are aided by use of the conceptual framework of the hallmarks of cancer, and, acting by a variety of genomic and nongenomic mechanisms, EDCs have now been shown to enable all the hallmarks of cancer to develop in human breast cancer cells. Many studies report that hallmarks can develop at concentrations which are within the range of those measured in human breast tissues, especially when added as mixtures. The varied levels of different EDCs measured in individual breast tissue samples together with the overlapping and complementary mechanisms of action of the EDCs imply that thematic mechanisms will be driven inevitably by different chemical mixtures. Despite the complexity, EDCs do need to now be acknowledged as a risk factor for breast cancer in order for preventative strategies to include reduction in EDC exposure.

Personal exposures to traffic-related air pollution in three Canadian bus transit systems: the Urban Transportation Exposure Study

BACKGROUND

Exposure to traffic-related air pollution (TRAP) is associated with increased incidence of several cardiopulmonary diseases. The elevated TRAP exposures of commuting environments can result in significant contributions to daily exposures.

OBJECTIVES

To assess the personal TRAP exposures (UFPs, BC, PM_2.5, and PM₁₀) of the bus transit systems of Toronto, Ottawa, and Vancouver, Canada. Personal exposure models estimated the contribution of bus commuting to daily TRAP exposures. Associations between bus type and riding exposures and bus stop/station type and waiting exposures were estimated.

RESULTS

Bus commuting (4.6% of the day) contributed ~59%(SD = 15%), 60%(SD = 20%), and 57%(SD = 18%) of daily PM_2.5-Ba and 70%(SD = 19%), 64%(SD = 15%), and 70%(SD = 15%) of daily PM_2.5-Fe, in Toronto, Ottawa, and Vancouver, respectively. Enclosed bus stations were found to be hotspots of PM_2.5 and BC. Buses with diesel particulate filters (DPFs) and hybrid diesel/electric propulsion were found to have significantly lower in-bus PM_2.5, UFP, and BC relative to 1983-2003 diesel buses in each city with the exception of UFP in Vancouver.

SIGNIFICANCE

Personal exposures for traffic-related air pollutants were assessed for three Canadian bus transit systems. In each system, bus commuting was estimated to contribute significantly toward daily exposures of fine-fraction Ba and Fe as well as BC. Exposures while riding were associated with bus type for several pollutants in each city. These associations suggest the use of hybrid diesel/electric buses equipped with diesel particulate filters have improved air quality for riders.

Multiple performances and paradoxical effects of China's vehicle emission reduction policy

As the living standards of urban residents in China continue to improve, the number of motor vehicle trips is increasing, thus aggravating air pollution. Such pollution causes great harm to human health and the global environment. Using a system dynamics approach, this study analyzed the effect of implementation mode on China's air pollution charging fee (APCF) policy and identified potentially negative medium- and long-term effects. The results indicated that the APCF policy has a dual effect under the single-charge mode (i.e., fees are charged on a daily basis). On the one hand, it has multiple effects of reducing emissions, relieving traffic congestion, and improving the happiness index. On the other hand, the higher the charge, the stronger the trip demand (possibly due to the sunk-cost fallacy and loss-aversion effect), which encourages motorists to weaken the cost of losses (i.e., from air pollution fees) by increasing the number of trips per day to seek short-term psychological balance, regardless of the extra costs and the amount of pollution generated. It was also found that APCF implementation mode significantly affected passenger car trips but not truck trips (perhaps because truck trips are mainly based on the demand of supply, and the daily number of trips is relatively stable). Overall, as APCF increases, it can have some paradoxical long-term effects on emissions, congestion, the happiness index, and road bearing capacity. This study's findings can help the Chinese government improve and optimize its long-term air pollution control strategies.

Relationship between Air Pollutant Exposure and Gynecologic Cancer Risk

Exposure to air pollution has been suggested to be associated with an increased risk of women's health disorders. However, it remains unknown to what extent changes in ambient air pollution affect gynecological cancer. In our case-control study, the logistic regression model was combined with the restricted cubic spline to examine the association of short-term exposure to air pollution with gynecological cancer events using the clinical data of 35,989 women in Beijing from December 2008 to December 2017. We assessed the women's exposure to air pollutants using the monitor located nearest to each woman's residence and working places, adjusting for age, occupation, ambient temperature, and ambient humidity. The adjusted odds ratios (ORs) were examined to evaluate gynecologic cancer risk in six time windows (Phase 1-Phase 6) of women's exposure to air pollutants (PM2.5, CO, O3, and SO2) and the highest ORs were found in Phase 4 (240 days). Then, the higher adjusted ORs were found associated with the increased concentrations of each pollutant (PM2.5, CO, O3, and SO2) in Phase 4. For instance, the adjusted OR of gynecological cancer risk for a 1.0-mg m-3 increase in CO exposures was 1.010 (95% CI: 0.881-1.139) below 0.8 mg m-3, 1.032 (95% CI: 0.871-1.194) at 0.8-1.0 mg m-3, 1.059 (95% CI: 0.973-1.145) at 1.0-1.4 mg m-3, and 1.120 (95% CI: 0.993-1.246) above 1.4 mg m-3. The ORs calculated in different air pollution levels accessed us to identify the nonlinear association between women's exposure to air pollutants (PM2.5, CO, O3, and SO2) and the gynecological cancer risk. This study supports that the gynecologic risks associated with air pollution should be considered in improved public health preventive measures and policymaking to minimize the dangerous effects of air pollution.

Breast Cancer Risk in Association with Atmospheric Pollution Exposure: A Meta-Analysis of Effect Estimates Followed by a Health Impact Assessment

BACKGROUND

The epidemiological literature of associations between atmospheric pollutant exposure and breast cancer incidence has recently strongly evolved.

OBJECTIVES

We aimed to perform a) a meta-analysis of studies considering this relationship, correcting for publication bias and taking menopausal status and cancer hormone responsiveness into account; and b) for the pollutants most likely to affect breast cancer, an assessment of the corresponding number of attributable cases in France and of the related economic costs.

METHODS

We conducted a literature review and random-effects meta-analyses of epidemiological studies examining the association of fine particulate matter with aerodynamic diameter less than or equal to 2.5μm (PM2.5), particulate matter with aerodynamic diameter less than or equal to 10 μm (PM10), and NO2 long-term exposure with breast cancer incidence; additional analyses were stratified on menopausal status and on tumor hormone responsiveness status. The resulting dose-response functions were combined with modeled atmospheric pollutant exposures in 2013 for France, cancer treatments costs, lost productivity, and years of life lost, to estimate the number of breast cancers attributable to atmospheric pollution and related economic costs in France.

RESULTS

The review identified 32, 27, and 36 effect estimates for PM2.5, PM10, and NO2, respectively. The meta-analytical relative risk estimates of breast cancer corrected for publication bias were 1.006 [95% confidence interval (CI): 0.941, 1.076], 1.047 (95% CI: 0.984, 1.113), and 1.023 (95% CI: 1.005, 1.041), respectively. NO2 estimated effects appeared higher in premenopausal than in postmenopausal women and higher for hormone responsive positive (ER+/PR+) than negative (ER-/PR-) breast cancers. Assuming a causal effect of NO2, we estimated that 1,677 (95% CI: 374, 2,914) new breast cancer cases were attributable to NO2 annually in France, or 3.15% (95% CI: 0.70, 5.48) of the incident cases. The corresponding tangible and intangible costs were estimated to be €825 million (low, high: 570, 1,080) per year.

CONCLUSION

These findings suggest that decreasing long-term NO2 exposure or correlated air pollutant exposures could lower breast cancer risk. https://doi.org/10.1289/EHP8419.

Air pollution and breast cancer risk in the Black Women's Health Study

BACKGROUND

Air pollution contains numerous carcinogens and endocrine disruptors which may be relevant for breast cancer. Previous research has predominantly been conducted in White women; however, Black women may have higher air pollution exposure due to geographic and residential factors.

OBJECTIVE

We evaluated the association between air pollution and breast cancer risk in a large prospective population of Black women.

METHODS

We estimated annual average ambient levels of particulate matter <2.5 μm (PM_2.5), nitrogen dioxide (NO₂) and ozone (O₃) at the 1995 residence of 41,317 participants in the Black Women's Health Study who resided in 56 metropolitan areas across the United States. Cox proportional hazards regression was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for an interquartile range (IQR) increase in each pollutant. We evaluated whether the association varied by menopausal status, estrogen receptor (ER) status of the tumor and geographic region of residence.

RESULTS

With follow-up through 2015 (mean = 18.3 years), 2146 incident cases of breast cancer were confirmed. Higher exposure to NO₂ or O₃ was not associated with a higher risk of breast cancer. For PM_2.5, although we observed no association overall, there was evidence of modification by geographic region for both ER- (p for heterogeneity = 0.01) and premenopausal breast cancer (p for heterogeneity = 0.01). Among women living in the Midwest, an IQR increase in PM_2.5 (2.87 μg/m³), was associated with a higher risk of ER- (HR = 1.53, 95% CI: 1.07-2.19) and premenopausal breast cancer (HR = 1.32, 95% CI: 1.03-1.71). In contrast, among women living in the South, PM_2.5 was inversely associated with both ER- (HR = 0.74, 95% CI: 0.56-0.97) and premenopausal breast cancer risk (HR = 0.75, 95% CI: 0.62-0.91).

DISCUSSION

Overall, we observed no association between air pollution and increased breast cancer risk among Black women, except perhaps among women living in the Midwestern US.

Breast cancer incidence and the air pollution level in the communes of Chile: an ecological study

There is evidence linking air pollutants associated with vehicular traffic such as polycyclic aromatic hydrocarbons with breast carcinogenesis. Epidemiological studies have shown conflicting results regarding air pollution and breast cancer risk, which could be explained by the multitude of other risk factors that could affect the association. In Chile, air pollution has reached alarming levels, either due to motorised vehicle traffic or the combustion of wood for heating; therefore, our objective was to evaluate the association between the incidence of breast cancer and the concentration of the main air pollutants monitored in the country.

We carried out a cross-sectional ecological study that evaluated the association between the average incidence of breast cancer in years (2016 to 2018) and the average annual concentration of six atmospheric pollutants in the 5 years prior to the estimation of the rate in communes of Chile, using the population of beneficiaries of Instituto Oncológico Fundación Arturo López Pérez. The annual incidence of breast cancer was 72.21 cases per 100,000 women and it varied significantly in the communes studied compared to the human development index (HDI) and to the proportion of women in the age group at highest risk. Assessing the relationship between the incidence of breast cancer and the average concentration of atmospheric pollutants, we only found a direct correlation between the level of nitrogen dioxide and the rate (R = 0.82; p = 0.044), whose significance tends to be lost when age and the communal HDI are included in a regression model.

Fine particulate matter PM2.5 generated by building demolition increases the malignancy of breast cancer MDA-MB-231 cells

OBJECTIVES

This study investigates the effects of water-extracted PM_2.5 on a triple-negative breast cancer (TNBC) cell line, MDA-MB-231, by sampling suspended particulates around a building demolition site.

METHODS

PM_2.5 particles were obtained using a high-flow TISCH sampler. Water-soluble PM_2.5 were extracted by an ultrasonic oscillator and then freeze-dried. The heavy metal components of soluble PM_2.5 was analyzed by ICP-MS. Cell viability was evaluated by MTT assay for cells that were exposed to PM_2.5 (200, 400 and 600 μg/mL). Wound healing and transwell cell migration and invasion assays were used to measure cell motility and the invasiveness of cancer cells that had been exposed to PM_2.5 into a chemo-attractant substance. Interrelated mechanisms of cancer malignancy were analyzed by Western blot analysis.

RESULTS

Nearby PM_2.5 concentrations increased significantly during the deconstruction of buildings, and the Cd, Cu, Pb, Zn and Cr contents of soluble PM_2.5 also significantly increased. Following exposure to PM_2.5, the survival rate of breast cancer cells was significantly higher than that of the control group. Soluble PM_2.5-treated cells had a higher migration capacity. The signaling pathway of FAK/PI3K/AKT proteins was more activated in PM_2.5-treated cells than the control group. Increased levels of Aurora B and Bcl-2 were associated with cell proliferation. Elevated levels of cathepsins D, β-catenin, N-cadherin, vimentin and MMP-9 were associated with breast cancer cell metastasis.

CONCLUSION

Soluble PM_2.5 from building demolition may promote/progress in surviving TNBC cells, increasing the malignancy of breast cancer. This study offered evidence of a link between demolition PM_2.5 and cancer progression.

Analysis of air pollutants in Covid 19 pandemic lockdown- a case study of Bareilly, UP, India

The contemporary world is dealing with the rise of the novel coronavirus pandemic. Globally, as on September 14, 2020, there have been 28,918,900 confirmed cases of COVID-19, including 922,252 deaths, reported to WHO with the cases still on the rise. In India, as a preventive measure, complete lockdown was imposed all over the country from 25th March 2020 which has significantly reduced the vehicular movement. Bareilly was reported among the seven most air polluted cities of Uttar Pradesh where PM10 was almost four times the annual standard of 60 ​μg/m³ averaging 226 ​μg/m³ for the year 2015 and 2016.The city Bareilly of State Uttar Pradesh do not have too much of industries and therefore industries cannot be blamed. Alternatively, vehicular or construction emission sources could not be ruled out and it can be concluded that primary sources of air pollution could be either automobiles or incomplete construction work. The present study is focused on monitoring of air pollutants PM10, PM2.5, SO₂ and NO₂, at Bareilly district of Uttar Pradesh and analyzed during the lockdown period due to pandemic COVID 19 from three monitoring stations. In the first week of lockdown, i.e. from March 25, 2020 to March 31, 2020 the PM10 and PM2.5 concentration averaged 60 ​μg/m³ and 47 ​μg/m³ respectively which is below the NAAQS average limits of 80 ​μg/m³ and 60 ​μg/m³ respectively. Whereas the concentrations of gaseous pollutants SO₂ and NO₂ was found to be much below the monthly NAAQS limits of 60 ​μg/m³ averaging 21 ​μg/m³ and 15 ​μg/m³ respectively. In April 2020, the vehicular movement was minimum and the level of air pollutants, PM10, PM2.5, SO₂ and NO₂, were found to be 54 ​μg/m³, 41 ​μg/m³, 19 ​μg/m³ and 14 ​μg/m³ respectively which is minimum in the six months of study from January 2020 to June 2020 and lowest in comparison to the air quality data of last 25 years.It can therefore be concluded that vehicular emissions contribute significantly for air pollution in Bareilly city.

Evaluation of air quality in Sunway City, Selangor, Malaysia from a mobile monitoring campaign using air pollution micro-sensors

Due to the increase of the human population and the rapid industrial growth in the past few decades, air quality monitoring is essential to assess the pollutant levels of an area. However, monitoring air quality in a high-density area like Sunway City, Selangor, Malaysia is challenging due to the limitation of the local monitoring network. To establish a comprehensive data for air pollution in Sunway City, a mobile monitoring campaign was employed around the city area with a duration of approximately 6 months, from September 2018 to March 2019. Measurements of air pollutants such as carbon dioxide (CO₂) and nitrogen dioxide (NO₂) were performed by using mobile air pollution sensors facilitated with a GPS device. In order to acquire a more in-depth understanding on traffic-related air pollution, the measurement period was divided into two different time blocks, which were morning hours (8 a.m.-12 p.m.) and afternoon hours (3 p.m.-7 p.m.). The data set was analysed by splitting Sunway City into different zones and routes to differentiate the conditions of each region. Meteorological variables such as ambient temperature, relative humidity, and wind speed were studied in line with the pollutant concentrations. The air quality in Sunway City was then compared with various air quality standards such as Malaysian Air Quality Standards and World Health Organisation (WHO) guidelines to understand the risk of exposure to air pollution by the residence in Sunway City.

Probabilistic predictive principal component analysis for spatially misaligned and high-dimensional air pollution data with missing observations

Accurate predictions of pollutant concentrations at new locations are often of interest in air pollution studies on fine particulate matters (PM2.5), in which data is usually not measured at all study locations. PM2.5 is also a mixture of many different chemical components. Principal component analysis (PCA) can be incorporated to obtain lower-dimensional representative scores of such multi-pollutant data. Spatial prediction can then be used to estimate these scores at new locations. Recently developed predictive PCA modifies the traditional PCA algorithm to obtain scores with spatial structures that can be well predicted at unmeasured locations. However, these approaches require complete data, whereas multi-pollutant data tends to have complex missing patterns in practice. We propose probabilistic versions of predictive PCA which allow for flexible model-based imputation that can account for spatial information and subsequently improve the overall predictive performance.

Mitigation strategies for reducing air pollution

Today, it is increasingly recognized that air pollution hurts human health. Consequently, efficient mitigation strategies need to be implemented for substantial environmental and health co-benefits. A valid approach to reducing the air pollution effects on the environment and human health is proposed. Specific guidelines have been elucidated by differentiating them on the base of the final stakeholders (citizens, enterprises, and public authorities), of the emission sources (transport, household energy, industry, and energy generation sector, agriculture, and shipping area), and of the field of implementation (urban and extra-urban context). This paper can provide useful information for governments for the implementation of a strategic plan focused on emphasizing multi-pollutant emission reductions and overall air pollution-related risk.

Fine Particulate Matter Air Pollution and Mortality among Pediatric, Adolescent, and Young Adult Cancer Patients

BACKGROUND

Air pollution is a carcinogen and causes pulmonary and cardiac complications. We examined the association of fine particulate matter pollution (PM_2.5) and mortality from cancer and all causes among pediatric, adolescent, and young adult (AYA) patients with cancer in Utah, a state with considerable variation in PM_2.5.

METHODS

We followed 2,444 pediatric (diagnosed ages 0-14) and 13,459 AYA (diagnosed ages 15-39) patients diagnosed in 1986-2015 from diagnosis to 5 and 10 years postdiagnosis, death, or emigration. We measured average monthly PM_2.5 by ZIP code during follow-up. Separate pediatric and AYA multivariable Cox models estimated the association of PM_2.5 and mortality. Among AYAs, we examined effect modification of PM_2.5 and mortality by stage while controlling for cancer type.

RESULTS

Increases in PM_2.5 per 5 μg/m³ were associated with cancer mortality in pediatric lymphomas and central nervous system (CNS) tumors at both time points, and all cause mortality in lymphoid leukemias [HR_5-year = 1.32 (1.02-1.71)]. Among AYAs, PM_2.5 per 5 μg/m³ was associated with cancer mortality in CNS tumors and carcinomas at both time points, and all cause mortality for all AYA cancer types [HR_5-year = 1.06 (1.01-1.13)]. PM_2.5 ≥12 μg/m³ was associated with cancer mortality among breast [HR_5-year = 1.50 (1.29-1.74); HR_10-year = 1.30 (1.13-1.50)] and colorectal cancers [HR_5-year = 1.74 (1.29-2.35); HR_10-year = 1.67 (1.20-2.31)] at both time points. Effect modification by stage was significant, with local tumors at highest risk.

CONCLUSIONS

PM_2.5 was associated with mortality in pediatric and AYA patients with specific cancers.

IMPACT

Limiting PM_2.5 exposure may be important for young cancer patients with certain cancers.See all articles in this CEBP Focus section, "Environmental Carcinogenesis: Pathways to Prevention."

The externalities of energy production in the context of development of clean energy generation

In this paper, we present a comparative review of the externalities of electricity production. First of all, the environmental impact is considered. A discussion of the influence of various electricity production processes on human health follows. The studies are conducted in the context of historical development. Current trends, as well as a historical background that resulted in the changes that can be observed today, are presented. The considerations are supported by a few case studies. Analysis of perspectives for the development of electricity generation methods, in particular the indication of clean energy sources and the perspectives of their exploitation, is the main aim of this paper.

Impact of air pollution on breast cancer incidence and mortality: a nationwide analysis in South Korea

Breast cancer is one of the major female health problems worldwide. Although there is growing evidence indicating that air pollution increases the risk of breast cancer, there is still inconsistency among previous studies. Unlike the previous studies those had case-control or cohort study designs, we performed a nationwide, whole-population census study. In all 252 administrative districts in South Korea, the associations between ambient NO2 and particulate matter 10 (PM10) concentration, and age-adjusted breast cancer mortality rate in females (from 2005 to 2016, Nmortality = 23,565), and incidence rate (from 2004 to 2013, Nincidence = 133,373) were investigated via multivariable beta regression. Population density, altitude, rate of higher education, smoking rate, obesity rate, parity, unemployment rate, breastfeeding rate, oral contraceptive usage rate, and Gross Regional Domestic Product per capita were considered as potential confounders. Ambient air pollutant concentrations were positively and significantly associated with the breast cancer incidence rate: per 100 ppb CO increase, Odds Ratio OR = 1.08 (95% Confidence Interval CI = 1.06-1.10), per 10 ppb NO2, OR = 1.14 (95% CI = 1.12-1.16), per 1 ppb SO2, OR = 1.04 (95% CI = 1.02-1.05), per 10 µg/m3 PM10, OR = 1.13 (95% CI = 1.09-1.17). However, no significant association between the air pollutants and the breast cancer mortality rate was observed except for PM10: per 10 µg/m3 PM10, OR = 1.05 (95% CI = 1.01-1.09).

Direct and Indirect Environmental Aspects of an Electric Bus Fleet Under Service

The reduction of pollutant emissions in the field of transportation can be achieved by developing and implementing electric propulsion technologies across a wider range of transportation types. This solution is seen as the only one that can offer, in areas of urban agglomeration, a reduction of the emissions caused by the urban transport to zero, as well as an increase in the degree of the health of the citizens. This paper presents an analysis of the direct and indirect environmental aspects of a fleet of real electric buses under service in the city of Cluj-Napoca, Romania. The solution of using 41 electric buses to replace Euro-3 diesel buses (with high pollution levels) in the city’s transport system eliminates a local amount of 668.45 tons of CO2 and 6.41 tons of NOx—pollutant emissions directly associated with harmful effects on human health—annually.

Long-term exposure to air pollution and the risk of non-lung cancer: a meta-analysis of observational studies

AIMS

Several meta-analyses of observational studies report a long-term correlation between air pollution and the risk of cancer, particularly lung carcinoma. The aim of this study was to review and quantify evidence for an association between air pollution and the risk of developing non-lung cancers.

METHODS

We searched PubMed, EMBASE, Cochrane Library, and the reference lists of the included studies as well as those recorded in previous meta-analyses conducted before January 2019. A random-effects model was used to derive overall risk estimates per pollutant.

RESULTS

A total of 20 studies, including 5 case-control and 15 prospective cohort studies, were used in the final analysis. The risk of developing non-lung cancer was 1.09 (95% confidence interval (CI): 1.01-1.18, I² = 72.9%) per NO₂ increases of 10 µg/m³. There was also a significant association between exposure to PM_2.5 and PM₁₀ and the risk of non-lung cancer when the male and female populations were combined (pooled odds ratio/relative risk (OR/RR) = 1.22, 95% CI: 1.11-1.34; I² = 0.0% and pooled OR/RR = 1.26, 95% CI: 1.05-1.52; I² = 43.9%, respectively). Regarding the type of cancer, significant harmful effects of PM_2.5 were observed for liver cancer populations (pooled OR/RR = 1.21, 95% CI: 1.10-1.32; I² = 0.0%). Different types of cancer were positively associated with the incidence of non-lung cancer and PM₁₀ in the random-effect meta-regression analysis.

CONCLUSIONS

Long-term exposure to air pollutants appears to be associated with an increased risk of non-lung cancer. Care should be taken in interpretation, because the results for specific cancers were restricted.

Associations between incident breast cancer and ambient concentrations of nitrogen dioxide from a national land use regression model in the Canadian National Breast Screening Study

BACKGROUND

Air pollution has been classified as a human carcinogen based largely on epidemiological studies of lung cancer. Recent research suggests that exposure to ambient air pollution increases the risk of female breast cancer especially in premenopausal women.

METHODS

Our objective was to determine the association between residential exposure to ambient nitrogen dioxide (NO₂) and newly diagnosed cases of invasive breast cancer in a cohort of 89,247 women enrolled in the Canadian National Breast Screening Study between 1980 and 1985. Vital status and incident breast cancers through 2005 were determined through record linkage to the Canadian national mortality and cancer registries. Estimates of exposures to NO₂ using participants' addresses at time of entry into the study were derived from a national land use regression model. We classified women as reaching menopause according to information obtained at baseline. In addition, as we had no information from women on their menopausal status during the observation period, we conducted analyses using different cut-points for defining postmenopausal status (i.e., at 50 or at 52 years of age), and hence we had four non-independent cohorts. We computed rate ratios for the incidence of breast cancer and their 95% confidence intervals (CI) separately for premenopausal and postmenopausal women. Our Cox models used attained age as the time axis and the rate ratios were adjusted for several individual-level risk factors, including reproductive history, as well as census-based neighborhood-level characteristics.

RESULTS

The median concentration of NO₂ was about 15 parts per billion (ppb). After adjusting for personal risk factors and contextual variables, we found no evidence of associations for the incidence of breast cancer in the postmenopausal cohorts. In premenopausal women, the rate ratio for an increase of 9.7 ppb (about the interquartile range) was 1.13 (95%CI: 0.94-1.37) for the 50 years of age cut-off for menopausal status and it was 1.17 (95%CI: 1.00-1.38) for the 52 years of age cut-off.

CONCLUSIONS

Our findings suggest that exposure to low concentrations of NO₂, a marker for traffic-related air pollution, increases the risk of premenopausal breast cancer, but not postmenopausal breast cancer.

Analysis of incidence, mortality trends, and geographic distribution of breast cancer patients in Canada

BACKGROUND/PURPOSE

Breast cancer is the malignancy with the highest incidence rate excluding non-melanoma skin cancers, and the second leading cause of cancer-related deaths among Canadian women. Many modifiable risk factors have been linked to the pathogenesis of this disease. The purpose of this study is to analyze the epidemiology of breast cancer in Canada and to examine its geographic distribution to help identify new risk factors for this disease.

METHODS

Three independent population-based cancer registries were used to retrospectively analyze demographic data from Canadian women diagnosed with invasive breast cancer across all provinces and territories between 1992 and 2010. The incidence and mortality rates were assessed at the provincial, city, and forward sortation area (FSA) postal code levels.

RESULTS

The overall age-adjusted incidence rate was 114.4 cases per 100,000 females per year. Six provinces and several groups of FSAs had significantly higher incidence rates. There was a significant increase in incidence and decrease in mortality rates between 1992 and 2010. The overall mortality rate was 31.5 deaths per 100,000 females per year. However, three provinces had significantly higher mortality rates.

CONCLUSION

By identifying high-incidence areas for breast cancer, our study will help identify patient populations that are at higher risk for this malignancy. It will also act as a foundation for future studies to establish novel risk factors for this disease.

Exposure to ambient air pollution and the incidence of lung cancer and breast cancer in the Ontario Population Health and Environment Cohort

Lung and female breast cancers are highly prevalent worldwide. Although the association between exposure to ambient fine particulate matter (PM_2.5 ) and lung cancer has been recognized, there is less evidence for associations with other common air pollutants such as nitrogen dioxide (NO₂ ) and ozone (O₃ ). Even less is known about potential associations between these pollutants and breast cancer. We conducted a population-based cohort study to investigate the associations of chronic exposure to PM_2.5 , NO₂ , O₃ and redox-weighted average of NO₂ and O₃ (O_x ) with incident lung and breast cancer, using the Ontario Population Health and Environment Cohort (ONPHEC), which includes all long-term residents aged 35-85 years who lived in Ontario, Canada, 2001-2015. Incident lung and breast cancers were ascertained using the Ontario Cancer Registry. Annual estimates of exposures were assigned to the residential postal codes of subjects for each year during follow-up. We used Cox proportional-hazards models adjusting for personal- and neighborhood-level covariates. Our cohorts for lung and breast cancer analyses included ~4.9 million individuals and ~2.5 million women, respectively. During follow-up, 100,146 incident cases of lung cancer and 91,146 incident cases of breast cancer were diagnosed. The fully adjusted analyses showed positive associations of lung cancer incidence with PM_2.5 (hazard ratio [HR] = 1.02 [95% CI: 1.01-1.05] per 5.3 μg/m³ ) and NO₂ (HR = 1.05 [95% CI: 1.03-1.07] per 14 ppb). No associations with lung cancer were observed for O₃ or O_x . Relationships between PM_2.5 and NO₂ with lung cancer exhibited a sublinear shape. We did not find compelling evidence linking air pollution to breast cancer.

Is breast cancer a result of epigenetic responses to traffic-related air pollution? A review of the latest evidence

Environmental toxicants can exert adverse health effects via epigenetic regulation. We conducted a review of studies assessing traffic-related air pollution (TRAP) exposure and breast cancer (BC) risk, and the evidence for epigenetic mediation. 14 epidemiological studies demonstrated associations between TRAP exposure and BC risk, in which a total of 26 comparisons were assessed. 11 of these comparisons reported a positive association; whereas 15 comparisons were negative. Five publications linked TRAP exposure to epigenetic alterations in genes that may be related to BC risk. One animal study provided evidence of TRAP-treatment inducing breast tumorigenesis. Associations between TRAP components polycyclic aromatic hydrocarbons (PAH) and nitrogen dioxide (NO₂) and BC risk were more consistent. While evidence for epigenetic regulation remains limited, polycyclic aromatic hydrocarbons (PAH) and nitrogen dioxide (NO₂) exposures may alter methylation of breast tumorigenic genes (e.g., EPHB2, LONP1). Future epigenomic studies with environmental measures are needed to interrogate the relationship between TRAP and BC risk.

Association between ambient air pollution and breast cancer risk: The multiethnic cohort study

Previous studies using different exposure methods to assess air pollution and breast cancer risk among primarily whites have been inconclusive. Air pollutant exposures of particulate matter and oxides of nitrogen were estimated by kriging (NO_x , NO₂ , PM₁₀ , PM_2.5 ), land use regression (LUR, NO_x , NO₂ ) and California Line Source Dispersion model (CALINE4, NO_x , PM_2.5 ) for 57,589 females from the Multiethnic Cohort, residing largely in Los Angeles County from recruitment (1993-1996) through 2010. Cox proportional hazards models were used to examine the associations between time-varying air pollution and breast cancer incidence adjusting for confounding factors. Stratified analyses were conducted by race/ethnicity and distance to major roads. Among all women, breast cancer risk was positively but not significantly associated with NO_x (per 50 parts per billion [ppb]) and NO₂ (per 20 ppb) determined by kriging and LUR and with PM_2.5 and PM₁₀ (per 10 μg/m³ ) determined by kriging. However, among women who lived within 500 m of major roads, significantly increased risks were observed with NO_x (hazard ratio [HR] = 1.35, 95% confidence interval [95% CI]: 1.02-1.79), NO₂ (HR = 1.44, 95% CI: 1.04-1.99), PM₁₀ (HR = 1.29, 95% CI: 1.07-1.55) and PM_2.5 (HR = 1.85, 95% CI: 1.15-2.99) determined by kriging and NO_x (HR = 1.21, 95% CI:1.01-1.45) and NO₂ (HR = 1.26, 95% CI: 1.00-1.59) determined by LUR. No overall associations were observed with exposures assessed by CALINE4. Subgroup analyses suggested stronger associations of NO_x and NO₂ among African Americans and Japanese Americans. Further studies of multiethnic populations to confirm the effects of air pollution, particularly near-roadway exposures, on the risk of breast cancer is warranted.

Spatial Clusters of Breast Cancer Mortality and Incidence in the Contiguous USA: 2000-2014

BACKGROUND

Clusters of breast cancer with varied incidence or mortality are known to exist. No national scale of analysis of geographical variation in breast cancer incidence has been published before for the contiguous USA.

METHODS

This was a spatial cluster analysis of incidence and mortality data on breast cancer in the contiguous USA at the county resolution. Data for the years 2000-2014 were downloaded and analyzed with the software SaTScan with the goal to identify significant spatial clusters of breast cancer. Regression analysis was used to then adjust breast cancer incidence and mortality for several key risk factors such as age, smoking, particulate matter air pollution, physical inactivity, urban living, education level, and race.

RESULTS

Spatial clusters of counties for higher than expected breast cancer incidence and also for breast cancer mortality were identified. All identified clusters have p < 0.05. The mortality clusters show the mean breast cancer rates inside the cluster, while the incidence clusters show the relative risk inside each cluster. This is the first study of the contiguous USA for breast cancer mortality and incidence together. The clustering for mortality is quite different from the clustering for incidence. Using the software JOINPOINT, it is shown that the annual US downward trend for breast cancer mortality slowed down in recent years.

CONCLUSIONS

There exist several significant clusters in the contiguous USA, both for breast cancer incidence and for breast cancer mortality. Some of the clusters persisted even after adjusting for several key risk factors. These geographic areas warrant further investigation to potentially identify additional local concerns or needs to further address female breast cancer in those specific sites.

Airborne metals and polycyclic aromatic hydrocarbons in relation to mammographic breast density

Background

Breast density is strongly related to breast cancer. Identifying associations between environmental exposures and density may elucidate relationships with breast cancer. Metals and polycyclic aromatic hydrocarbons (PAHs) may influence breast density via oxidative stress or endocrine disruption.

Methods

Study participants (n = 222,581) underwent a screening mammogram in 2011 at a radiology facility in the Breast Cancer Surveillance Consortium. Zip code residential levels of airborne PAHs and metals (arsenic, cadmium, chromium, cobalt, lead, manganese, mercury, nickel, and selenium) were assessed using the 2011 EPA National Air Toxics Assessment. Breast density was measured using the Breast Imaging–Reporting and Data System (BI-RADS) lexicon. Logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CI) for the individual air toxics and dense breasts (BI-RADS 3 or 4). Weighted quantile sum (WQS) regression was used to model the association between the air toxic mixture and density.

Results

Higher residential levels of arsenic, cobalt, lead, manganese, nickel, or PAHs were individually associated with breast density. Comparing the highest to the lowest quartile, higher odds of having dense breasts were observed for cobalt (OR = 1.60, 95% CI 1.56–1.64) and lead (OR = 1.56, 95% CI 1.52–1.64). Associations were stronger for premenopausal women. The WQS index was associated with density overall (OR = 1.22, 95% CI 1.20–1.24); the most heavily weighted air toxics were lead and cobalt.

Conclusions

In this first study to evaluate the association between air toxics and breast density, women living in areas with higher concentrations of lead and cobalt were more likely to have dense breasts.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1110-7) contains supplementary material, which is available to authorized users.

Development and performance evaluation of a GIS-based metric to assess exposure to airborne pollutant emissions from industrial sources

BACKGROUND

Dioxins are environmental and persistent organic carcinogens with endocrine disrupting properties. A positive association with several cancers, including risk of breast cancer has been suggested.

OBJECTIVES

This study aimed to develop and assess performances of an exposure metric based on a Geographic Information System (GIS) through comparison with a validated dispersion model to estimate historical industrial dioxin exposure for its use in a case-control study nested within a prospective cohort.

METHODS

Industrial dioxin sources were inventoried over the whole French territory (n > 2500) and annual average releases were estimated between 1990 and 2008. In three selected areas (rural, urban and urban-costal), dioxin dispersion was modelled using SIRANE, an urban Gaussian model and exposure of the French E3N cohort participants was estimated. The GIS-based metric was developed, calibrated and compared to SIRANE results using a set of parameters (local meteorological data, characteristics of industrial sources, e.g. emission intensity and stack height), by calculating weighted kappa statistics (wκ) and coefficient of determination (R2). Furthermore, as performance evaluation, the final GIS-based metric was tested to assess atmospheric exposure to cadmium.

RESULTS

The concordance between the GIS-based metric and the dispersion model for dioxin exposure estimate was strong (wκ median = 0.78 (1st quintile = 0.72, 3rd quintile =0.82) and R2 median = 0.82 (1st quintile = 0.71, 3rd quintile = 0.87)). We observed similar performance for cadmium.

CONCLUSIONS

Our study demonstrated the ability of the GIS-based metric to reliably characterize long-term environmental dioxin and cadmium exposures as well as the pertinence of using dispersion modelling to construct and calibrate the GIS-based metric.