Relationship between particulate matter exposure and female breast cancer incidence and mortality: a systematic review and meta-analysis

Associations of incident female breast cancer with long-term exposure to PM2.5 and its constituents: Findings from a prospective cohort study in Beijing, China

This study aimed to investigate the association between long-term exposure to fine particulate matter (PM2.5) and its constituents (black carbon (BC), ammonium (NH4+), nitrate (NO3-), organic matter (OM), inorganic sulfate (SO42-)) and incident female breast cancer in Beijing, China. Data from a prospective cohort comprising 85,504 women enrolled in the National Urban Cancer Screening Program in Beijing (2013-2019) and the Tracking Air Pollution in China dataset are used. Monthly exposures were aggregated to calculate 5-year average concentrations to indicate long-term exposure. Cox models and mixture exposure models (weighted quantile sum, quantile-based g-computation, and explanatory machine learning model) were employed to analyze the associations. Findings indicated increased levels of PM2.5 and its constituents were associated with higher breast cancer risk, with hazard ratios per 1-μg/m3 increase of 1.02 (95% confidence interval (CI): 1.01, 1.03), 1.39 (95% CI: 1.16, 1.65), 1.28 (95% CI: 1.12, 1.46), 1.15 (95% CI: 1.05, 1.24), 1.05 (95% CI: 1.02, 1.08), and 1.15 (95% CI: 1.07, 1.23) for PM2.5, BC, NH4+, NO3-, OM, and SO42-, respectively. Exposure-response curves demonstrated a monotonic risk increase without an evident threshold. Mixture exposure models highlighted BC and SO42- as key factors, underscoring the importance of reducing emissions of these pollutants.

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.

The association between ambient air pollution exposure and connective tissue sarcoma risk: a nested case-control study using a nationwide population-based database

A nationwide population-based database was utilized in a nested case-control study to explore the association between ambient air pollution exposure and the likelihood of developing connective tissue sarcoma. The study examined 280 cases of connective tissue sarcoma diagnosed between 2000 and 2012. A random sample of 1120 control subjects was selected from a subpopulation of claim records without a connective tissue sarcoma diagnosis in a 1:4 ratio. The control subjects were selected based on similar characteristics as the connective tissue sarcoma patients, including gender, birth year, and the year of diagnosis of the case group with medical records. Risk factors for connective tissue sarcoma were collected for analysis. Our data on exposure to air pollutants was collected from Taiwan's Air Quality Monitoring Network, which has been gathering air quality data from a growing network of sampling stations (now 76) throughout the country since 1997. It was discovered that the risk of connective tissue sarcoma was significantly increased by the Charlson comorbidity index (CCI), elevated levels of specific air pollution indices (e.g., total hydrocarbons (THC), fine particulate matter (PM2.5), and O3_8 (the annual mean of the daily maximum 8-h average concentration of O3), the High Pollutant Standards Index (hPSI) (the percentage of days in a given year in Taiwan where the PSI exceeds 100), and an insurable monthly wage over US$1100. Further investigation is needed to explore the involvement of these air pollutants in the formation of connective tissue sarcoma.

Ambient fine particulate matter and breast cancer incidence in a large prospective US cohort

BACKGROUND

Fine particulate matter (PM2.5) has been inconsistently associated with breast cancer incidence, however, few studies have considered historic exposure when levels were higher.

METHODS

Outdoor residential PM2.5 concentrations were estimated using a nationwide spatiotemporal model for women in the National Institutes of Health-AARP Diet and Health Study, a prospective cohort located in 6 states (California, Florida, Louisiana, New Jersey, North Carolina, and Pennsylvania) and 2 metropolitan areas (Atlanta, GA, and Detroit, MI) and enrolled in 1995-1996 (n = 196 905). Annual average PM2.5 concentrations were estimated for a 5-year historical period 10 years prior to enrollment (1980-1984). We used Cox regression to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between a 10 µg/m3 increase in PM2.5 and breast cancer incidence overall and by estrogen receptor status and catchment area.

RESULTS

With follow-up of participants through 2017, a total of 15 870 breast cancer cases were identified. A 10 ug/m3 increase in PM2.5 was statistically significantly associated with overall breast cancer incidence (HR = 1.08, 95% CI = 1.02 to 1.13). The association was evident for estrogen receptor-positive (HR = 1.10, 95% CI = 1.04 to 1.17) but not estrogen receptor-negative tumors (HR = 0.97, 95% CI = 0.84 to 1.13; Pheterogeneity = .3). Overall breast cancer hazard ratios were more than 1 across the catchment areas, ranging from a hazard ratio of 1.26 (95% CI = 0.96 to 1.64) for North Carolina to a hazard ratio of 1.04 (95% CI = 0.68 to 1.57) for Louisiana (Pheterogeneity = .9).

CONCLUSIONS

In this large US cohort with historical air pollutant exposure estimates, PM2.5 was associated with risk of estrogen receptor-positive breast cancer. State-specific estimates were imprecise but suggest that future work should consider region-specific associations and the potential contribution of PM2.5 chemical constituency in modifying the observed association.

Effect of air pollution on the prevalence of breast and cervical cancer in China: a panel data regression analysis

The association between the prevalence of breast and cervical cancer in Chinese women and air pollution is obscure. The study aims to analyze the correlation between air pollution and the prevalence of breast and cervical cancer, and whether the gross domestic product (GDP) has a modifying effect on the impact of air pollution on the prevalence of breast and cervical cancer. Extracting panel data from 31 provinces and cities between 2006 and 2020, we evaluated the association between breast and cervical cancer prevalence and pollutant emissions from 2006 to 2015 with two-way fixed-effect models. We also analyzed the interaction between GDP and pollutant emissions and further check the robustness of the moderating effect results using group regression from 2016 to 2020. Cluster robust standard errors were used to correct for the heteroskedasticity and autocorrelation. The coefficients of models show that the coefficients of logarithmic soot and dust emissions are estimated to be significantly positive, and the coefficients of their square terms are significantly negative. The robust results suggest that the relationship between soot and dust emissions and breast or cervical cancer prevalence is non-linear, from 2006 to 2015. In the analysis of particulate matter (PM) data in 2016-2020, the PM-GDP interaction term was also significantly negative, indicating that GDP growth weakened the effect of PM on the prevalence of breast cancer and cervical cancer. In provinces with higher GDP, the indirect effect of PM emissions concerning breast cancer is -0.396 while in provinces with lower GDP, it is about -0.215. The corresponding coefficient concerning cervical cancer is about -0.209 in provinces with higher GDP but not significant in provinces with lower GDP. Our results suggest that there is an inverted U-shaped relationship between the prevalence of breast cancer and cervical cancer and air pollutants from 2006 to 2015. GDP growth has a significant negative moderating effect on the impact of air pollutants on the prevalence of breast cancer and cervical cancer. PM emissions have a higher effect on the prevalence of breast and cervical cancer in provinces with higher GDP and a lower impact in provinces with lower GDP.

Long-term exposure to fine particulate matter and site-specific cancer mortality: A difference-in-differences analysis in Jiangsu province, China

BACKGROUND

Accumulating studies have reported that chronic exposure to ambient fine particulate matter (PM_2.5) can lead to adverse effects on lung cancer mortality; however, such chronic effects are less clear for mortality from other site-specific cancers.

OBJECTIVE

To explore the causal effect of long-term PM_2.5 exposure on mortality from all-site and a variety of site-specific cancers in Jiangsu province, China during 2015-2020 using a difference-in-differences analysis.

METHODS

For each of 53 county-based spatial units in Jiangsu province, we calculated annual death counts for all-site cancer and 23 site-specific cancers. Using a validated high-resolution PM_2.5 grid dataset, long-term PM_2.5 exposure of a spatial unit within a given year was evaluated as the average of population-weighted annual concentrations during recent 10 years. Conditional Poisson regression models were employed to evaluate exposure-response associations adjusting for spatial and temporal variables, seasonal temperatures, relative humidity, and gross domestic product (GDP).

RESULTS

During the study period, we identified 947,337 adult cancer deaths in Jiangsu province. Each 1 μg/m³ increment in PM_2.5 exposure was significantly associated with a 2.7% increase in the risk of all-site cancer mortality. PM_2.5-mortality associations were also observed in cancer of lip, oral cavity and pharynx, stomach, colorectum, pancreas, lung, bone and joints, ovary, prostate, and lymphoma (all adjusted P < 0.05), with the relative risks ranging from 1.028 (95% confidence interval [CI]: 1.011, 1.046) for stomach cancer to 1.201 (95% CI: 1.120, 1.308) for bone and joints cancers. Exposure-response curves showed that these associations were close to linearity, though most of them had increasing slopes at high exposure levels. Overall, women and subjects in low GDP regions were more vulnerable to PM_2.5 exposures.

CONCLUSIONS

Long-term exposure to ambient PM_2.5 contributes to a higher risk of mortality from multiple site-specific cancers.

Ambient Fine Particulate Matter and Cancer: Current Evidence and Future Perspectives

The high incidence of cancer has placed an enormous health and economic burden on countries around the world. In addition to evidence of epidemiological studies, conclusive evidence from animal experiments and mechanistic studies have also shown that morbidity and mortality of some cancers can be attributed to ambient fine particulate matter (PM_2.5) exposure, especially in lung cancer. However, the underlying carcinogenetic mechanisms of PM_2.5 remain unclear. Furthermore, in terms of risks of other types of cancer, both epidemiological and mechanistic evidence are more limited and scattered, and the results are also inconsistent. In order to sort out the carcinogenic effect of PM_2.5, this paper reviews the association of cancers with PM_2.5 based on epidemiological and biological evidence including genetic, epigenetic, and molecular mechanisms. The limitations of existing researches and the prospects for the future are also well clarified in this paper to provide insights for future studies.

In vivo tracking of toxic diesel particulate matter in mice using radiolabeling and nuclear imaging

Exposure to diesel particulate matter (DPM) is associated with several adverse health effects, including severe respiratory diseases. Quantitative analysis of DPM in vivo can provide important information on the behavior of harmful chemicals, as well as their toxicological impacts in living subjects. This study presents whole-body images and tissue distributions of DPM in animal models, using molecular imaging and radiolabeling techniques. The self-assembly of the ⁸⁹Zr-labeled pyrene analog with a suspension of DPM efficiently produced ⁸⁹Zr-incorporated DPM (⁸⁹Zr-DPM). Positron emission tomography images were obtained for mice exposed to ⁸⁹Zr-DPM via three administration routes: intratracheal, oral, and intravenous injection. DPM was largely distributed in the lungs and only slowly cleared after 7 days in mice exposed via the intratracheal route. In addition, a portion of ⁸⁹Zr-DPM was translocated to other organs, such as the heart, spleen, and liver. Uptake values in these organs were also noticeable following exposure via the intravenous route. In contrast, most of the orally administered DPM was excreted quickly within a day. These results suggest that continuous inhalation exposure to DPM causes serious lung damage and may cause toxic effects in the extrapulmonary organs.

Nano-Based Theranostic Platforms for Breast Cancer: A Review of Latest Advancements

Breast cancer (BC) is a highly metastatic multifactorial disease with various histological and molecular subtypes. Due to recent advancements, the mortality rate in BC has improved over the past five decades. Detection and treatment of many cancers are now possible due to the application of nanomedicine in clinical practice. Nanomedicine products such as Doxil^® and Abraxane^® have already been extensively used for BC adjuvant therapy with favorable clinical outcomes. However, these products were designed initially for generic anticancer purposes and not specifically for BC treatment. With a better understanding of the molecular biology of BC, several novel and promising nanotherapeutic strategies and devices have been developed in recent years. In this context, multi-functionalized nanostructures are becoming potential carriers for enhanced chemotherapy in BC patients. To design these nanostructures, a wide range of materials, such as proteins, lipids, polymers, and hybrid materials, can be used and tailored for specific purposes against BC. Selective targeting of BC cells results in the activation of programmed cell death in BC cells and can be considered a promising strategy for managing triple-negative BC. Currently, conventional BC screening methods such as mammography, digital breast tomosynthesis (DBT), ultrasonography, and magnetic resonance imaging (MRI) are either costly or expose the user to hazardous radiation that could harm them. Therefore, there is a need for such analytical techniques for detecting BC that are highly selective and sensitive, have a very low detection limit, are durable, biocompatible, and reproducible. In detecting BC biomarkers, nanostructures are used alone or in conjunction with numerous molecules. This review intends to highlight the recent advances in nanomedicine in BC treatment and diagnosis, emphasizing the targeting of BC cells that overexpress receptors of epidermal growth factors. Researchers may gain insight from these strategies to design and develop more tailored nanomedicine for BC to achieve further improvements in cancer specificity, antitumorigenic effects, anti-metastasis effects, and drug resistance reversal effects.

A Real-Time Comparison of Four Particulate Matter Size Fractions in the Personal Breathing Zone of Paris Subway Workers: A Six-Week Prospective Study

We developed a Bayesian spline model for real-time mass concentrations of particulate matter (PM10, PM2.5, PM1, and PM0.3) measured simultaneously in the personal breathing zone of Parisian subway workers. The measurements were performed by GRIMM, a gravimetric method, and DiSCmini during the workers’ work shifts over two consecutive weeks. The measured PM concentrations were analyzed with respect to the working environment, the underground station, and any specific events that occurred during the work shift. Overall, PM0.3 concentrations were more than an order of magnitude lower compared to the other PM concentrations and showed the highest temporal variation. The PM2.5 levels raised the highest exposure concern: 15 stations out of 37 had higher mass concentrations compared to the reference. Station PM levels were not correlated with the annual number of passengers entering the station, the year of station opening or renovation, or the number of platforms and tracks. The correlation with the number of station entrances was consistently negative for all PM sizes, whereas the number of correspondence concourses was negatively correlated with PM0.3 and PM10 levels and positively correlated with PM1 and PM2.5 levels. The highest PM10 exposure was observed for the station platform, followed by the subway cabin and train, while ticket counters had the highest PM0.3, PM1, and PM2.5 mass concentrations. We further found that compared to gravimetric and DiSCmini measurements, GRIMM results showed some discrepancies, with an underestimation of exposure levels. Therefore, we suggest using GRIMM, calibrated by gravimetric methods, for PM sizes above 1μm, and DiSCmini for sizes below 700 nm.

Long-term PM2.5 exposure and various health outcomes: An umbrella review of systematic reviews and meta-analyses of observational studies

Adverse effects from exposure to particulate matter <2.5 μm in diameter (PM_2.5) on health-related outcomes have been found in a range of experimental and epidemiological studies. This study aimed to assess the significance, validity, and reliability of the relationship between long-term PM_2.5 exposure and various health outcomes. The Embase, PubMed, Web of Science, CNKI, WANFANG, VIP, and SinoMed databases and reference lists of the retrieved review articles were searched to obtain meta-analysis and systematic reviews focusing on PM_2.5-related outcomes as of August 31, 2021. Random-/fixed-effects models were applied to estimate summary effect size and 95% confidence intervals (CIs). The quality of included meta-analyses was evaluated based on the AMSTAR 2 tool. Small-study effect and excess significance bias studies were conducted to further assess the associations. Registered PROSPERO number: CRD42020200606. This included 24 articles involving 71 associations between PM_2.5 exposure and the health outcomes. The evidence for the positive association of 10 μg/m³ increments of long-term exposure to PM_2.5 and stroke incidence in Europe was convincing (effect size = 1.07, 95% CI: 1.05-1.10). There was evidence that was highly suggestive of a positive association between 10 μg/m³ increments of long-term exposure to PM_2.5 and the following health-related outcomes: mortality of lung cancer (effect size = 1.11, 95% CI: 1.08-1.13) and Alzheimer's disease (effect size = 4.79, 95% CI: 2.79-8.21). There was highly suggestive evidence that chronic obstructive pulmonary disease risk is positively associated with higher long-term PM_2.5 exposure versus lower long-term PM_2.5 exposure (effect size = 2.32, 95% CI: 1.88-2.86). In conclusion, the positive association of long-term exposure to PM_2.5 and stroke incidence in Europe was convincing. Given the validity of numerous associations of long-term exposure to PM_2.5 and health-related outcomes is subject to biases, more robust evidence is urgently needed.

Ambient air pollution and COVID-19 risk: Evidence from 35 observational studies

BACKGROUND AND AIMS

The coronavirus disease 2019 (COVID-19) pandemic is severely threatening and challenging public health worldwide. Epidemiological studies focused on the influence of outdoor air pollution (AP) on COVID-19 risk have produced inconsistent conclusions. We aimed to quantitatively explore this association using a meta-analysis.

METHODS

We searched for studies related to outdoor AP and COVID-19 risk in the Embase, PubMed, and Web of Science databases. No language restriction was utilized. The search date entries were up to August 13, 2021. Pooled estimates and 95% confidence intervals (CIs) were obtained with random-/fixed-effects models. PROSPERO registration number: CRD42021244656.

RESULTS

A total of 35 articles were eligible for the meta-analysis. For long-term exposure to AP, COVID-19 incidence was positively associated with 1 μg/m³ increase in nitrogen dioxide (NO₂; effect size = 1.042, 95% CI 1.017-1.068), particulate matter with diameter <2.5 μm (PM_2.5; effect size = 1.056, 95% CI 1.039-1.072), and sulfur dioxide (SO₂; effect size = 1.071, 95% CI 1.002-1.145). The COVID-19 mortality was positively associated with 1 μg/m³ increase in nitrogen dioxide (NO₂; effect size = 1.034, 95% CI 1.006-1.063), PM_2.5 (effect size = 1.047, 95% CI 1.025-1.1071). For short-term exposure to air pollutants, COVID-19 incidence was positively associated with 1 unit increase in air quality index (effect size = 1.001, 95% CI 1.001-1.002), 1 μg/m³ increase NO₂ (effect size = 1.014, 95% CI 1.011-1.016), particulate matter with diameter <10 μm (PM₁₀; effect size = 1.005, 95% CI 1.003-1.008), PM_2.5 (effect size = 1.003, 95% CI 1.002-1.004), and SO₂ (effect size = 1.015, 95% CI 1.007-1.023).

CONCLUSIONS

Outdoor air pollutants are detrimental factors to COVID-19 outcomes. Measurements beneficial to reducing pollutant levels might also reduce the burden of the pandemic.

Health damage to housewives by contaminants emitted from coal combustion in the Chinese countryside: focusing on day-to-day cooking

PURPOSE

The study aimed to estimate the health damage and find out the main exposure pathways of housewives posed by polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) from coal combustion in rural areas of China.

METHODS

We obtained the concentrations of 16 PAHs and 8 HMs from published literatures and the Monte Carlo simulation was used to process and analysis the data. Sensitivity analysis was also applied to clear parameter uncertainty and the health damage of housewives was quantitatively evaluated by loss of life expectancy.

RESULTS

Housewives' carcinogenic risks from PAHs exposure were in descending order of inhalation > ingestion > dermal contact, while exposed to HMs were ingestion > dermal contact > inhalation. The carcinogenic risks from PAHs primarily originated from benzo[a]pyrene (BaP), dibenz[ah]anthracene (DahA) and benzo[b]fluorathene (BbF). For HMs, arsenic posed the highest carcinogenic risk to housewives, with a contribution of 92.98%. In addition, the life expectancy loss of housewives exposed to PAHs was 469.04 min from inhalation and 51.82 min for HMs from ingestion.

CONCLUSION

Through a comprehensive assessment of the health risks in housewives exposed to emissions from coal combustion, we can gain insight into the hazards from PAHs and HMs in housewives, and take measures to reduce their exposure risks.

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.