Ambient Air Pollution and Cancer Mortality in the Cancer Prevention Study II

Bladder Cancer Incidence and Survival in the United States and Texas Non-Latino Whites and Latinos

BACKGROUND: Bladder cancer (BC) poses an enormous burden on health care systems. Latinos in Texas (TX) were underrepresented in previous studies on racial/ethnic disparity of BC in the US. OBJECTIVE: To examine whether BC incidence and survival rates differ among Latinos compared to non-Latino whites (NLW) in South TX, TX, and the US SEER. METHODS: Data was collected from the US SEER Program and the Texas Cancer Registry. Annual age-specific and age-adjusted BC incidence rates and annual 5-year relative survival were calculated. RESULTS: South TX and TX had significantly lower BC incidence rates than SEER for both Latinos and NLW regardless of gender (Ps < 0.05). South TX women had worse BC survival rates than SEER women for both Latinos and NLW (Ps < 0.05). TX NLW had worse BC survival rates than SEER NLW for both genders together and men only (Ps < 0.05). All Latino groups had lower incidence but worse survival rates than NLW groups for both men and women in each geographic area (all Ps < 0.05). Women had significantly lower BC incidence but worse survival rates than men regardless of race/ethnicity in each geographic area (all Ps < 0.05). CONCLUSIONS: South TX women had lower BC incidence but worse survival rates than US SEER women for both Latinos and NLW. Latinos had worse survival but lower incidence rates than NLW. Women had lower BC incidence but worse survival rates than men. The study identifies the BC distribution and high-risk population, racial/ethnic disparities, and geographic differences. It facilitates health care services planning.

Air pollution exposure and bladder, kidney and urinary tract cancer risk: A systematic review

BACKGROUND

Exposure to outdoor air pollution has been linked to lung cancer, and suspicion arose regarding bladder, kidney, and urinary tract cancer (urological cancers). However, most of evidence comes from occupational studies; therefore, little is known about the effect of exposure to air pollution on the risk of urological cancers in the general population.

METHOD

We systematically searched Medline, Scopus, and Web of Science for articles investigating the associations between long-term exposure to air pollution and the risk of urological cancer (incidence or mortality). We included articles using a specific air pollutant (PM₁₀, PM_2.5, …) or proxies (traffic, proximity index …). We assessed each study's quality with the Newcastle-Ottawa scale and rated the quality of the body of evidence for each pollutant-outcome with the GRADE approach. The different study methodologies regarding exposure or outcome prevented us to perform a meta-analysis.

RESULTS

twenty articles (four case-control, nine cohort, and seven ecologic) met our inclusion criteria and were included in this review: eighteen reported bladder, six kidney, and two urinary tract. Modeling air pollutants was the most common exposure assessment method. Most of the included studies reported positive associations between air pollution and urological cancer risk. However, only a few reached statistical significance (e.g. for bladder cancer mortality, adjusted odds-ratio of 1.13 (1.03-1.23) for an increase of 4.4 μg.m-3 of PM_2.5). Most studies inadequately addressed confounding, and cohort studies had an insufficient follow-up.

DISCUSSION

Overall, studies suggested positive (even though mostly non-significant) associations between air pollution exposure and bladder cancer mortality and kidney cancer incidence. We need more studies with better confounding control and longer follow-ups.

Continuous exposure to ambient air pollution and chronic diseases: prevalence, burden, and economic costs

Studies that assess the connection between the prevalence of chronic diseases and continuous exposure to air pollution are scarce in developing countries, mainly due to data limitations. Largely overcoming data limitations, this study aimed to investigate the association between the likelihood of reporting a set of chronic diseases (diabetes, cancer, stroke and myocardial infarction, asthma, and hypertension) and continuous exposure to carbon monoxide (CO), nitrogen dioxide (NO₂), ozone (O₃), and coarse particulate matter (PM10). Using the estimated associations, the disease burden and economic costs of continuous exposure to air pollutants were also approximated. A 2011 Health Equity Assessment and Response Tool survey from Tehran, Iran, was used in the main analyses. A sample of 67,049 individuals who had not changed their place of residence for at least 2 years before the survey and reported all relevant socioeconomic information was selected. The individuals were assigned with the average monthly air pollutant levels of the nearest of 16 air quality monitors during the 2 years leading to the survey. Both single- and multi-pollutant analyses were conducted. The country's annual household surveys from 2002 to 2011 were used to calculate the associated economic losses. The single-pollutant analysis showed that a one-unit increase in monthly CO (ppm), NO₂ (ppb), O₃ (ppb), and PM10 (μg/m³) during the 2 years was associated with 751 [confidence interval (CI): 512-990], 18 (CI: 12-24), 46 (CI: -27-120), and 24 (CI: 13-35) more reported chronic diseases in 100,000, respectively. The disease-specific analyses showed that a unit change in average monthly CO was associated with 329, 321, 232, and 129 more reported cases of diabetes, hypertension, stroke and myocardial infarction, and asthma in 100,000, respectively. The measured associations were greater in samples with older individuals. Also, a unit change in average monthly O₃ was associated with 21 (in 100,000) more reported cases of asthma. The multi-pollutant analyses confirmed the results from single-pollutant analyses. The supplementary analyses showed that a one-unit decrease in monthly CO level could have been associated with about 208 (CI: 147-275) years of life gained or 15.195 (CI: 10.296-20.094) thousand US dollars (USD) in life-time labor market income gained per 100,000 30-plus-year-old Tehranis.

Ambient carbon monoxide exposure and elevated risk of mortality in the glioblastoma patients: A double-cohort retrospective observational study

An increasing number of studies indicate air pollutants infiltrate into the brain. We aimed to find the association of cumulative air pollution exposure in the main body of primary brain tumor: glioblastoma (GBM). In this double-cohort, retrospective analysis study with a protocol, we compared the health effect of air pollution on the GBM patients from the SEER (Surveillance, Epidemiology, and End Results Program) in 27 U.S. counties from 10 states and GBM patients of Severance cohort of Korea. From 2000 to 2015, 10621 GBM patients of the SEER were individually evaluated for the cumulative average exposure for each pollutant, and 9444 (88.9%) mortality events were reported. From 2011 to 2018, 398 GBM patients of the Severance with the same protocol showed 259 (65.1%) mortality events. The multi-pollutant models show that the association level of risk with CO is increased in the SEER (HR 1.252; 95% CI 1.141-1.373) with an increasing linear trend of relative death rate in the spline curve. The Severance GBM data showed such a statistically significant result of the health impact of CO on GBM patients. The overall survival gain of the less exposure group against CO was 2 and 3 months in the two cohorts. Perioperative exposure to CO may increase the risk of shorter survival of GBM patients of the SEER and the Severance cohort.

Long-term exposure to nitrogen dioxide and natural-cause and cause-specific mortality in Japan

BACKGROUND

Long-term exposure to air pollution is linked with increased risk of adverse health outcomes, but the evidence for the association between nitrogen dioxide (NO₂) and mortality is weak because of the inadequate adjustment of potential confounders and limited spatial resolution of the exposure assessment. Moreover, there are concerns about the independent effects of NO₂. Therefore, we examined the association between NO₂ long-term exposure and all-cause and cause-specific mortality.

METHODS

We included participants who were enrolled in health checkups in Okayama City, Japan, in 2006 or 2007 and were followed until 2016. We used a land-use regression model to estimate the average NO₂ concentrations from 2006 to 2007 and allocated them to the participants. We estimated hazard ratios (HRs) for a 10-μg/m³ increase in NO₂ levels for all-cause or cause-specific mortality using Cox proportional hazard models.

RESULTS

After excluding the participants who were assigned with outlier exposures, a total of 73,970 participants were included in the analyses. NO₂ exposure was associated with increased risk of mortality and the HRs and their confidence intervals were 1.06 (95% CI: 1.02, 1.11) for all-cause, 1.02 (0.96, 1.09) for cardiopulmonary, and 1.36 (1.14, 1.63) for lung cancer mortality. However, the elevated risks became equivocal after the adjustment for fine particulate matter except lung cancer.

CONCLUSION

Long-term exposure to NO₂ was associated with increased risk of all-cause, cardiopulmonary, and lung cancer mortality. The elevated risk for lung cancer was still observable even after adjustment for fine particulate matter.

The association between air pollution and cancers: controversial evidence of a systematic review

There are inconsistent reports on the association between air pollution and cancers. This systematic review was, therefore, conducted to ascertain the relationship between air pollution and some cancers. This is a systematic review study, which all articles published in this area were extracted from January 1, 1950 to December 31, 2018 from Web of Science, PubMed, Scopus, Cochrane Library, MEDLINE, EMBASE, Science Direct, Google scholar. Searching was performed independently by two search-method experts. The required data were extracted from the articles by an author-made questionnaire. Forty-eight articles were investigated. Evidence linking air pollution to some cancers is limited. Leukemia had the highest association with exposure to various air pollutants and bladder cancer had the lowest association. It is noteworthy that the specific type of pollutants in all studies was not specified. Based on the findings, the results are contradictory, and the role of air pollution in some cancers cannot be supported. Accordingly, studies are recommended to be performed at the individual level or multifactorial studies to specifically investigate the relationship between air pollution and these types of cancers. In this way, the role of air pollution in the incidence of these cancers can be determined more accurately.

Components of particulate matter air-pollution and brain tumors

BACKGROUND

Air pollution is an established carcinogen. Evidence for an association with brain tumors is, however, inconclusive. We investigated if individual particulate matter constituents were associated with brain tumor risk.

METHODS

From comprehensive national registers, we identified all (n = 12 928) brain tumor cases, diagnosed in Denmark in the period 1989-2014, and selected 22 961 controls, matched on age, sex and year of birth. We established address histories and estimated 10-year mean residential outdoor concentrations of particulate matter < 2.5 µm, primarily emitted black carbon (BC) and organic carbon (OC), and combined carbon (OC/BC), as well as secondary inorganic and organic PM air pollutants from a detailed dispersion model. We used conditional logistic regression to calculate odds ratios (OR) per inter quartile range (IQR) exposure. We adjusted for income, marital and employment status as well as area-level socio-demographic characteristics.

RESULTS

Total tumors of the brain were associated with OC/BC (OR: 1.053, 95%CI: 1.005-1.103, per IQR). The data suggested strongest associations for malignant tumors with ORs per IQR for OC/BC, BC and OC of 1.063 (95% CI: 1.007-1.123), 1.036 (95% CI: 1.006-1.067) and 1.030 (95%CI: 0.979-1.085), respectively. The results did not indicate adverse effects of other PM components.

CONCLUSIONS

This large, population based study showed associations between primary emitted carbonaceous particles and risk for malignant brain tumors. As the first of its kind, this study needs replication.

Residential proximity to industrial pollution sources and colorectal cancer risk: A multicase-control study (MCC-Spain)

BACKGROUND

Colorectal cancer is the third most frequent tumor in males and the second in females worldwide. In Spain, it is an important and growing health problem, and epidemiologic research focused on potential risk factors, such as environmental exposures, is necessary.

OBJECTIVES

To analyze the association between colorectal cancer risk and residential proximity to industries, according to pollution discharge route, industrial groups, categories of carcinogens and other toxic substances, and specific pollutants released, in the context of a population-based multicase-control study of incident cancer carried out in Spain (MCC-Spain).

METHODS

MCC-Spain included 557 colorectal cancer cases and 2948 controls in 11 provinces, frequency matched by sex, age, and region of residence. Distances were computed from subjects' residences to each of the 134 industries located in the study area. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance (from 1 km to 3 km) to industrial facilities, adjusting for matching variables and other confounders.

RESULTS

Excess risk (OR; 95%CI) of colorectal cancer was detected near industries overall for all distances analyzed, from 1 km (2.03; 1.44-2.87) to 3 km (1.26; 1.00-1.59). In general, industries releasing pollutants to air showed higher excess risks than facilities releasing pollution to water. By industrial sector, excess risk (OR; 95%CI) was found near (≤3 km) production of metals (2.66; 1.77-4.00), surface treatment of metals (1.48; 1.08-2.02), glass and mineral fibers (2.06; 1.39-3.07), organic chemical industry (4.80; 3.20-7.20), inorganic chemical industry (6.74; 4.38-10.36), food/beverage sector (3.34; 2.38-4.68), and surface treatment using organic solvents (6.16; 4.06-9.36). By pollutants, the main excess risks (OR; 95%CI) were found near (≤3 km) industries releasing nonylphenol (9.19; 5.91-14.28), antimony (5.30; 3.45-8.15), naphthalene (3.11; 2.16-4.49), organotin compounds (2.64; 1.76-3.98), manganese (2.53; 1.63-3.93), dichloromethane (2.52; 1.74-3.66), and vanadium (2.49; 1.59-3.91).

CONCLUSIONS

Our results support the hypothesis that residing in the proximity of industries may be a risk factor for colorectal cancer.

Air Pollution Associates with Cancer Incidences in Poland

In many countries around the world (including the United States, Canada, and Spain), research is being conducted into the impact of air pollution on the formation of various types of cancer. For a long time it was thought that the inhalation of pollutants could lead to lung diseases. Now the effects of air pollutants on tumors in the airways, kidneys, bladder, breast, and colon have been investigated and are better understood. It is now known that particulates in air pollution can cross the blood–brain barrier and also reach the placenta. The aim of this study was to find a possible relationship between the emission of pollutants into the atmosphere and the formation of specific types of tumors in the Polish population. Two databases available on the Internet were used in the analysis: the bank of measurement data on air quality in Poland (the repository of Environmental Protection Inspection) and cancer statistics. The pollution measurement data for the years 2000–2016 were taken from the Chief Inspectorate for Environmental Protection website, a database with results from 264 stations located in Poland for 13 types of gases and atmospheric pollutants. Statistical data on cancer C00–D09 (according to the International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10)) in the Polish population in the years 1999–2015 were retrieved from onkologia.org.pl. A novel code was constructed, allowing the downloading of statistics from the databases, examination of their correlation, and selection of the best model of regression through machine learning. The results of the analyses indicate a high correlation of air pollution with the incidence of selected types of cancer. Particularly noteworthy is the observed effect of NOx on the incidence of small and large intestine cancers in the Masovia and West Pomerania provinces. The other gases and pollutants with the most significant impact on the incidence of gastrointestinal cancer have also been identified. Based on statistical analysis, we found a correlation between air pollution and tumor incidence in individual provinces, as well as an influence of the emission of nitrogen oxides on the cancer incidence rate.

Accumulated ambient air pollution and colon cancer incidence in Thailand

This research examined the relationship between colon cancer risks and pollution in various areas of Thailand, using satellites to gather quantities of aerosols in the atmosphere. Bayesian hierarchical spatio-temporal model and the Poisson log-linear model were used to examine the incidence rates of colon cancer standardized by national references; from the database of the National Health Security Office, Ministry of Public Health of Thailand and NASA's database from aerosol diagnostics model. Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2) was used to explore disease-gender-specific spatio-temporal patterns of colon cancer incidences and accumulated air pollution-related cancers in Thailand between 2010 and 2016. A total of 59,605 patients were selected for the study. Due to concerns regarding statistical reliability between aerosol diagnostics model and colon cancer incidences, the posterior probabilities of risk appeared the most in dust PM_2.5. It could be interpreted as relative risk in every increase of 10 μg/m³ in black carbon, organic carbon, and dust-PM_2.5 levels were associated respectively with an increase of 4%, 4%, and 15% in the risks of colon cancer. A significant increase in the incidence of colon cancer with accumulated ambient air quality raised concerns regarding the prevention of air pollution. This study utilized data based on the incidences of colon cancer; the country's database and linked cancer data to pollution. According to the database from NASA's technology, this research has never been conducted in Thailand.

Impact of modelled PM2.5, NO2 and O3 annual air concentrations on some causes of mortality in Tuscany municipalities

BACKGROUND

In 2014, the European Environment Agency estimated 59 630 premature deaths in Italy attributable to long-term exposure to PM2.5, 17 290 to NO2 and 2900 to O3. The aim of this study was to test an approach for assessing health impact of the above pollutants analyzing possible associations between annual municipal concentrations, estimated by the national dispersion model developed by ENEA, and mortality rates for trachea, bronchus and lung (TBL) cancer, total respiratory diseases (RD) and chronic obstructive pulmonary diseases (COPD). Tuscany was selected as test case.

METHODS

For the 287 municipalities, 2009-13 standardized mortality rates (SMRates) for each cause of death were calculated by the ENEA epidemiological database. The SMRates of municipalities, aggregated on the basis of the 2003 or 2010 estimated pollutant concentration tertiles, were also computed.

RESULTS

TBL cancer SMRate in municipalities with 2003 PM2.5 levels >15.2 μg/m3 was significantly higher than the SMRates of the two lowest tertiles and COPD SMRates in the two highest O3 tertiles were significantly higher than that of the lower tertile. No association between PM2.5 or NO2 concentrations and RD and COPD was detected. Approximately 625 TBL cancer deaths attributable to PM2.5 levels above 10 μg/m3 in 2003 were estimated in the region. Smoking habits and deprivation index were homogeneously distributed among municipalities.

CONCLUSION

This methodological approach allowed detecting associations between mortality and specific air pollutants even at levels below the Italian normative limits and could be employed to evaluate the potential health impact of air pollution in areas where direct measures of concentration are unavailable.

Air Pollution across the Cancer Continuum: Extending Our Understanding of the Relationship between Environmental Exposures and Cancer

Previous studies of the environment and cancer have focused on etiology, showing that extrinsic factors in the environment contribute to 70% to 90% of cancers. Cancer patients and survivors often continue to live in the same neighborhoods they resided in before their cancer diagnosis. Thus, patients and survivors are exposed to the same environmental contexts that likely contributed to their original cancer, but little is known about the health effects of continued exposure to carcinogens after a cancer diagnosis. This commentary provides a summary of studies of the association between PM_2.5 and cancer mortality among patients and PM_2.5 and posttreatment morbidity among cancer survivors, and proposes new directions and opportunities for future research on such topics.See all articles in this CEBP Focus section, "Environmental Carcinogenesis: Pathways to Prevention."

Fine Particulate Matter Exposure and Cancer Incidence: Analysis of SEER Cancer Registry Data from 1992-2016

BACKGROUND

Previous research has identified an association between fine particulate matter (PM 2.5 ) air pollution and lung cancer. Most of the evidence for this association, however, is based on research using lung cancer mortality, not incidence. Research that examines potential associations between PM 2.5 and incidence of non-lung cancers is limited.

OBJECTIVES

The primary purpose of this study was to evaluate the association between the incidence of cancer and exposure to PM 2.5 using > 8.5  million cases of cancer incidences from U.S. registries. Secondary objectives include evaluating the sensitivity of the associations to model selection, spatial control, and latency period as well as estimating the exposure-response relationship for several cancer types.

METHODS

Surveillance, Epidemiology, and End Results (SEER) program data were used to calculate incidence rates for various cancer types in 607 U.S. counties. County-level PM 2.5 concentrations were estimated using integrated empirical geographic regression models. Flexible semi-nonparametric regression models were used to estimate associations between PM 2.5 and cancer incidence for selected cancers while controlling for important county-level covariates. Primary time-independent models using average incidence rates from 1992-2016 and average PM 2.5 from 1988-2015 were estimated. In addition, time-varying models using annual incidence rates from 2002-2011 and lagged moving averages of annual estimates for PM 2.5 were also estimated.

RESULTS

The incidences of all cancer and lung cancer were consistently associated with PM 2.5 . The incident rate ratios (IRRs), per 10 - μ g / m 3 increase in PM 2.5 , for all and lung cancer were 1.09 (95% CI: 1.03, 1.14) and 1.19 (95% CI: 1.09, 1.30), respectively. Less robust associations were observed with oral, rectal, liver, skin, breast, and kidney cancers.

DISCUSSION

Exposure to PM 2.5 air pollution contributes to lung cancer incidence and is potentially associated with non-lung cancer incidence. https://doi.org/10.1289/EHP7246.

Synergistic and antagonistic interactions among organic and metallic components of the ambient particulate matter (PM) for the cytotoxicity measured by Chinese hamster ovary cells

Although PM_2.5 toxicity is known to be related to its chemical composition, the effect of interactions among various particles' components on the toxicity is not well explored. To understand these interactions, especially metals and organic compounds on PM_2.5 cytotoxicity, we chose several redox-active substances known to be present in the ambient particles such as metals (Cu, Fe, and Mn) and quinones [9,10-phenanthraquinone (PQ), 1,2-naphthoquinone (1,2-NQ), 1,4-naphthoquinone (1,4-NQ), and 5-hydroxy-1,4-naphthoquinone (5,H-1,4-NQ)]. Cytotoxicity was assessed through a Chinese hamster ovary (CHO) cells assay and expressed by a median lethal concentration (LC₅₀). Two methods were employed to assess the interactions. In the first method, we tested the impact of nontoxic level of a component on the LC₅₀ of other components. In the second method, we mixed two components in different concentration ratios to expose the cells and calculated a mixture toxicity index (MTI). MTI is a composite value to quantify the nature of interactions such that the interactions are considered synergistic when MTI > 1, additive when 0 < MTI ≤ 1 and antagonistic when MTI < 0. The interactions between quinones and metals were largely synergistic by both methods. To further assess the environmental relevance of these mixtures, we extracted organic compounds termed as water-soluble Humic-like substances (HULIS) from real ambient PM samples and mixed them with individual metals. A similar pattern, as observed from the interaction of quinones and metals, was found. Moreover, the interactions became more synergistic as the relative concentration of metals with respect to water-soluble HULIS was decreased in these mixtures. With environmentally relevant mass concentration ratios of organics to metals (75-7500), the interactions were strongly synergistic (MTI = 1-115). These results indicate the importance of incorporating the interaction among various PM components for estimating the net toxicity of ambient PM_2.5.

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

OBJECTIVES

The associations of PM with the risk and prognosis of breast cancer have not been determined. This systematic review aimed to provide an updated understanding of the relationship between PM exposure level and breast cancer incidence and mortality.

METHODS

Articles from Web of Science and PubMed databases were methodically inspected until March 8, 2020. In final, 15 studies were kept for analysis, which provided necessary information to estimate the impact of PM on breast cancer risk and prognosis. These studies were combined for quantitative analyses to evaluate the effect of per 10 μg /m³ increment exposure of PM_2.5 (< 2.5 μm in aerodynamic diameter) and PM₁₀ (< 10 μm in aerodynamic diameter) using random-effects model.

RESULTS

PM_2.5 exposure was associated with increased breast cancer mortality (relative risk [RR] = 1.09; 95% confidence interval [CI]: 1.02, 1.16; P_Q-test = 0.158). No association of PM_2.5 (1.02; 0.97, 1.18; 0.308) and PM₁₀ (1.03; 0.98, 1.09; 0.009) with the increase incidence of breast cancer was observed. Stratified analysis suggested that PM_2.5 was associated with the increase mortality of breast cancer (1.10; 1.03, 1.17; 0.529) in subgroup of developed country. PM₁₀ was associated with breast cancer incidence based on studies published after 2017 (1.08; 1.00, 1.15; 0.157) and European studies (1.15; 1.06, 1.25; 0.502).

CONCLUSIONS

Our study indicated that PM_2.5 exposure was related to breast cancer mortality. Further researches in this field are needed to validate the conclusion.

The Inducible Role of Ambient Particulate Matter in Cancer Progression via Oxidative Stress-Mediated Reactive Oxygen Species Pathways: A Recent Perception

Simple Summary

Particulate matter, especially the fine fraction PM2.5, is officially stated as carcinogenic to human. There are compelling evidences on the association between PM2.5 exposure and lung cancer, and there are also some preliminary data reporting the significant links between this fraction with non-lung cancers. The underlying mechanisms remain unclear. Further studies related to such scope are highly required. The purpose of this work is to systemically analyze recent findings concerning the relationship between PM2.5 and cancer, and to thoroughly present the oxidative stress pathways mediated by reactive oxygen species as the key mechanism for carcinogenesis induced by PM2.5. This will provide a more comprehensive and updated knowledge regarding carcinogenic capacity of PM2.5 to both clinicians and public health workers, contributing to preventive and therapeutic strategies to fight against cancer in human.

Abstract

Cancer is one of the leading causes of premature death and overall death in the world. On the other hand, fine particulate matter, which is less than 2.5 microns in aerodynamic diameter, is a global health problem due to its small diameter but high toxicity. Accumulating evidence has demonstrated the positive associations between this pollutant with both lung and non-lung cancer processes. However, the underlying mechanisms are yet to be elucidated. The present review summarizes and analyzes the most recent findings on the relationship between fine particulate matter and various types of cancer along with the oxidative stress mechanisms as its possible carcinogenic mechanisms. Also, promising antioxidant therapies against cancer induced by this poison factor are discussed.

Outdoor air pollution and cancer: An overview of the current evidence and public health recommendations

Outdoor air pollution is a major contributor to the burden of disease worldwide. Most of the global population resides in places where air pollution levels, because of emissions from industry, power generation, transportation, and domestic burning, considerably exceed the World Health Organization's health-based air-quality guidelines. Outdoor air pollution poses an urgent worldwide public health challenge because it is ubiquitous and has numerous serious adverse human health effects, including cancer. Currently, there is substantial evidence from studies of humans and experimental animals as well as mechanistic evidence to support a causal link between outdoor (ambient) air pollution, and especially particulate matter (PM) in outdoor air, with lung cancer incidence and mortality. It is estimated that hundreds of thousands of lung cancer deaths annually worldwide are attributable to PM air pollution. Epidemiological evidence on outdoor air pollution and the risk of other types of cancer, such as bladder cancer or breast cancer, is more limited. Outdoor air pollution may also be associated with poorer cancer survival, although further research is needed. This report presents an overview of outdoor air pollutants, sources, and global levels, as well as a description of epidemiological evidence linking outdoor air pollution with cancer incidence and mortality. Biological mechanisms of air pollution-derived carcinogenesis are also described. This report concludes by summarizing public health/policy recommendations, including multilevel interventions aimed at individual, community, and regional scales. Specific roles for medical and health care communities with regard to prevention and advocacy and recommendations for further research are also described.

Impact of residential mobility on estimated environmental exposures in a prospective cohort of older women

Longitudinal studies of environmental hazards often rely on exposure estimated at the participant's enrollment residence. This could lead to exposure misclassification if participants move over time.

Methods

We evaluated residential mobility in the Iowa Women's Health Study (age 55-69 years) over 19 years of follow-up (1986-2004). We assessed several environmental exposures of varying spatial scales at enrollment and follow-up addresses. Exposures included average nitrate concentrations in public water supplies, percent of agricultural land (row crops and pasture/hay) within 750 m, and the presence of concentrated animal feeding operations within 5 km. In comparison to gold standard duration-based exposures averaged across all residences, we evaluated the sensitivity and specificity of exposure metrics and attenuation bias for a hypothetical nested case-control study of cancer, which assumed participants did not move from their enrollment residence.

Results

Among 41,650 participants, 32% moved at least once during follow-up. Mobility was predicted by working outside the home, being a former/current smoker, having a higher education level, using a public drinking water supply, and town size of previous residence. Compared with duration-based exposures, the sensitivity and specificity of exposures at enrollment ranged from 94% to 99% and 97% to 99%, respectively. A hypothetical true odds ratio of 2.0 was attenuated 8% for nitrate, 9%-10% for agricultural land, and 6% for concentrated animal feeding operation exposures.

Conclusions

Overall, we found low rates of mobility and mobility-related exposure misclassification in the Iowa Women's Health Study. Misclassification and attenuation of hypothetical risk estimates differed by spatial variability and exposure prevalence.

The Effects of Fine Dust, Ozone, and Nitrogen Dioxide on Health

BACKGROUND

Air pollutants, especially fine dust, ozone, and nitrogen dioxide, pose a danger to health worldwide. In 2005, the World Health Organization (WHO), in order to protect public health, issued global recommendations for maximum levels of fine dust (10 μg/m3 for fine dust particles smaller than 2.5 μm [PM2.5]), ozone, and nitrogen dioxide. The recommended levels are regularly exceeded in many places in Germany.

METHODS

This review is based on relevant publications retrieved by a selective search in PubMed and, in part, on an expert statement issued in the name of the International Society for Environmental Epidemiology (ISEE) and the European Respiratory Society (ERS).

RESULTS

Air pollutants affect the entire body, from the beginning of intrauterine development all the way to the end of life, causing premature death mainly through lung and heart disease. An epidemiological study has shown, for example, that mor- tality rises approximately 7% for every incremental long-term exposure to 5 μg/m3 PM2.5 (95% confidence interval: [2; 13]). Aside from lung and heart disease, the carcinogenic effect of fine dust is now well established. High fine-dust exposure has also been linked to metabolic diseases. For example, in a meta-analysis of cohort studies, the incidence of type 2 diabetes mellitus was found to be associated with elevated fine dust concentrations, with a 25% relative risk increase [10; 43] for every 10 µg/m3 of PM2.5. More recent studies have shown that these substances cause harm even in concentrations that are below the recommended limits.

CONCLUSION

It is very important for public health that the current EU standards for rkedly lowered so that health risks can be further reduced, in accordance with the recommendations of the WHO.

Association between PM2.5 and mortality of stomach and colorectal cancer in Xi'an: a time-series study

Globally, fine particulate matter has been associated with several health problems including cancer. However, most studies focused mainly on lung cancer. Stomach and colorectal cancers play significant roles in increasing public health's cancer globally. This study focused on investigating a possible significant association between exposure to fine particulate matter (PM_2.5) and mortality due to stomach and colorectal cancer in Xi'an from 2014 to 2016. Using time-series analysis, the study applied both single and multi-pollutant(s) approaches for investigations; PM_2.5 was the pollutant of interest. Generalized additive model (GAM) was the core statistical method used with the addition of distributed lag model (DLM) to observe delayed effects. As a single pollutant, PM_2.5 was significantly associated with stomach cancer mortality only RR (95%CI): 1.0003 (1.0001, 1.002). For the multi-pollutant analysis, PM_2.5 combinations with NO₂ were significantly associated with both stomach and colorectal cancer mortality RR (95%CI): 1.0103 (1.009, 1.021) and 1.054 (1.0324, 1.0667), respectively. Also, PM_2.5 combination with O₃ was significantly associated with colorectal cancer mortality, RR (95%CI): 1.0151 (1.0091, 1.0172), but no association was noted for combination with SO₂. Though this study has reported significant associations, it will be beneficial for the public's health if more studies further investigate the relationship between exposure to PM_2.5 and other cancer mortality.

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."

Long-term exposure to ambient fine particles and gastrointestinal cancer mortality in Taiwan: A cohort study

BACKGROUND

Information on the association between long-term exposure to PM_2.5 and gastrointestinal cancer mortality is scarce.

OBJECTIVES

This study investigated the association between long-term exposure to PM_2.5 and deaths from gastrointestinal cancer and its subtypes in adults in Taiwan.

METHODS

A total of 385,650 Taiwanese adults (≥18 years old) jointed a standard medical examination program between 2001 and 2014 and were followed up until 2016. Their vital data were obtained from the National Death Registry maintained by the Ministry of Health and Welfare in Taiwan. We estimated the ambient PM_2.5 concentration at individual's address utilising a satellite-based spatiotemporal model at a resolution of 1 km². Cox proportional hazard regression model was used to investigate the associations between ambient PM_2.5 and deaths from gastrointestinal, stomach, colorectal and liver cancers.

RESULTS

We found that each 10 µg/m³ increase in PM_2.5 was associated with an increased hazard risk (HR) of 1.09 (95% confidence interval (CI): 1.03-1.16) and 1.13 (95%CI: 1.02-1.24) in deaths from gastrointestinal and liver cancers, respectively. The association between PM_2.5 and death from colorectal cancer was marginally statistically significant [HR: 1.13 (95%CI: 1.00-1.26)]. We did not find significant associations between PM_2.5 and mortality from stomach cancer.

CONCLUSIONS

Long-term exposure to ambient PM_2.5 was associated with an increased risk of deaths from gastrointestinal cancers, liver cancer and also potentially colorectal cancer. Air pollution control strategies are necessary to reduce the burden of gastrointestinal cancer.

Maternal exposure to ambient particulate matter and green spaces and fetal renal function

Exposure to air pollution has been associated with different harmful effects and exposure to greenspace has been related to improved human health. However, the available evidence on the impact of these exposures on renal function is still scarce. The aim of this study was to determine the relationship between exposure to ambient levels of PM₁, PM_2.5, PM₁₀ and indicators of exposure to traffic as well as greenspace during pregnancy and fetal renal function based on the umbilical cord blood. This study was based on 150 pregnant women residing in Sabzevar, Iran (2018). Multiple linear regression models were developed to estimate the association of glomerular filtration rate (GFR), creatinine (Cr) and blood urea nitrogen (BUN) with exposure to air pollution, traffic, and greenspace (one at a time) controlled for relevant covariates. There was an inverse significant association between exposure to PM₁, PM_2.5, PM₁₀ and total street length in a 100 m buffer around the home and eGFR. Increase in distance to major road and residential surrounding greenness (100 m buffer) was associated with increase in eGFR. We observed a significant direct association between exposure to PMs as well as street length in 100 m buffer and serum level of Cr. There was also an inverse association between distance to major road and NDVI in 100 m buffer and Cr. The associations for blood urea nitrogen (BUN) were not statistically significant. Our results suggest that exposure to air pollution during pregnancy could have negative impact and exposure to greenspace could have positive impact on renal function of fetal.

Impact of environmental factors on gastric cancer: A review of the scientific evidence, human prevention and adaptation

Globally, gastric cancer (GC) ranks fifth in prevalence and third in fatalities, and shows a distinct geographical distribution in morbidity and mortality. Such a spatial pattern indicates that environmental factors could be an important contributor to GC. We reviewed a total of 135 relevant peer-reviewed articles and other literature published 1936-2019 to investigate the scientific evidence concerning the effects of environmental factors on GC worldwide. Environmental factors affect GC from the aspects of water, soil, air, radiation, and geology. Risk factors identified include water type, water pollution, water hardness, soil type, soil pollution, soil element content, climate change, air pollution, radiation, altitude, latitude, topography, and lithology; and most of them have an adverse impact on GC. Furthermore, we found that their effects followed five common rules: (1) the leading environmental factors that affect GC incidence and mortality vary by region, (2) the same environmental factors may have different effects on GC in different regions, (3) some different environmental factors have similar effects on GC in essence, (4) different environmental factors often interact to have combined or synergistic effects on GC, and (5) environmental factors can affect human factors to have an impact on GC. Environmental factors have a great impact on GC. Human beings may prevent GC by controlling carcinogenic factors, screening high-risk populations and providing symptomatic and rehabilitative treatments. Furthermore, adaptation measures are recommended to reduce GC risk on private and public levels. Future studies should transcend existing empirical studies to develop causal relationship models and focus on vulnerable population analysis.

The interaction of gender and smoking on bladder cancer risks

PURPOSE OF REVIEW

Although smoking and gender are well-established bladder cancer (BCa) risk factors, a significant interaction with other risk factors could help in the identification of patterns for early detection and prevention strategies.

RECENT FINDINGS

Smoking appears to be more strongly associated with BCa risk in women than in men, which could be related to differences in metabolism, smoking behavior, exposure patterns, and DNA repair mechanisms. BMI is associated with a higher risk of BCa with negligible difference between genders. The risk for BCa is increased in postmenopausal women, specifically in women with earlier menopausal age (<45 years). Other potential risk factors such as alcohol, arsenic exposure, and particulate matter inhalation seem to affect the genders differently.Female smokers experience a higher risk of disease recurrence after bacillus Calmette-Guérin therapy than their male counterparts. Lastly, smoking appears to negatively affect the outcome of radiotherapy in women, but not that of men.

SUMMARY

Several lines of evidence point to an interaction between smoking and gender, whereas their impact on other potential risk factors remains to be elucidated. Identifying such differential effects could allow for gender-specific prevention, early detection, and treatment strategies.

Premature mortality related to United States cross-state air pollution

Outdoor air pollution adversely affects human health and is estimated to be responsible for five to ten per cent of the total annual premature mortality in the contiguous United States^1-3. Combustion emissions from a variety of sources, such as power generation or road traffic, make a large contribution to harmful air pollutants such as ozone and fine particulate matter (PM_2.5)⁴. Efforts to mitigate air pollution have focused mainly on the relationship between local emission sources and local air quality². Air quality can also be affected by distant emission sources, however, including emissions from neighbouring federal states^5,6. This cross-state exchange of pollution poses additional regulatory challenges. Here we quantify the exchange of air pollution among the contiguous United States, and assess its impact on premature mortality that is linked to increased human exposure to PM_2.5 and ozone from seven emission sectors for 2005 to 2018. On average, we find that 41 to 53 per cent of air-quality-related premature mortality resulting from a state's emissions occurs outside that state. We also find variations in the cross-state contributions of different emission sectors and chemical species to premature mortality, and changes in these variations over time. Emissions from electric power generation have the greatest cross-state impacts as a fraction of their total impacts, whereas commercial/residential emissions have the smallest. However, reductions in emissions from electric power generation since 2005 have meant that, by 2018, cross-state premature mortality associated with the commercial/residential sector was twice that associated with power generation. In terms of the chemical species emitted, nitrogen oxides and sulfur dioxide emissions caused the most cross-state premature deaths in 2005, but by 2018 primary PM_2.5 emissions led to cross-state premature deaths equal to three times those associated with sulfur dioxide emissions. These reported shifts in emission sectors and emission species that contribute to premature mortality may help to guide improvements to air quality in the contiguous United States.

Association Between Outdoor Air Pollution and Risk of Malignant and Benign Brain Tumors: The Multiethnic Cohort Study

Background

There are increasing concerns about the potential impact of air pollution on chronic brain inflammation and microglia cell activation, but evidence of its carcinogenic effects is limited.

Methods

We used kriging interpolation and land use regression models to estimate long-term air pollutant exposures of oxides of nitrogen (NO_x, NO₂), kriging interpolation for ozone (O₃), carbon monoxide, and particulate matter (PM_2.5, PM₁₀), and nearest monitoring station measurements for benzene for 103 308 men and women from the Multiethnic Cohort, residing largely in Los Angeles County from recruitment (1993–1996) through 2013. We used Cox proportional hazards models to examine the associations between time-varying pollutants and risk of malignant brain cancer (94 men, 116 women) and meningioma (130 men, 425 women) with adjustment for sex, race and ethnicity, neighborhood socioeconomic status, smoking, occupation, and other covariates. Stratified analyses were conducted by sex and race and ethnicity.

Results

Brain cancer risk in men increased in association with exposure to benzene (hazard ratio [HR] = 3.52, 95% confidence interval [CI] = 1.55 to 7.55) and PM₁₀ (HR = 1.80, 95% CI = 1.00 to 3.23). Stronger associations with PM₁₀ (HR = 3.02, 95% CI = 1.26 to 7.23), O₃ (HR = 2.93, 95% CI = 1.09 to 7.88), and benzene (HR = 4.06, 95% CI = 1.17 to 18.2) were observed among Latino men. Air pollution was unrelated to risk of meningioma except that O₃ exposure was associated with risk in men (HR = 1.77, 95% CI = 1.02 to 3.06). Brain cancer risk in women was unrelated to air pollution exposures.

Conclusions

Confirmation of these sex differences in air pollution–brain cancer associations and the stronger findings in Latino men in additional diverse populations is warranted.

The legacy of the Home Owners' Loan Corporation and the political ecology of urban trees and air pollution in the United States

This study examines the persistent impacts of historical racebased discriminatory housing policies on contemporary urban environments in the United States. Specifically, we examine the relationships between Home Owners' Loan Corporation (HOLC) grades assigned to neighborhoods in the 1930s and the current distribution of tree canopy and level of exposure to air pollution hazards. Our results indicate a clear gradient in tree canopy by HOLC grade, with better neighborhood grades associated with significantly higher percentage of tree canopy coverage. The pattern also exists for airborne carcinogens and respiratory hazards, with worse neighborhood grades associated with significantly higher hazards exposure. Our findings indicate that early 20th century discriminatory housing policies exert a contemporary influence on patterns of green space exposure in American cities, with implications for health and health inequities. Our findings suggest that, in order to achieve equitable access to the benefits of urban greenspace, we must acknowledge these historical influences and consider policies and practices that directly counter these influences, for example, through targeted greenspace development in areas historically identified as unfit for investment.

Internalization and toxicity: A preliminary study of effects of nanoplastic particles on human lung epithelial cell

As a kind of newly emerging pollutant, nanoplastics are easily to be ingested by organisms, and cause severe damage to biological functions because of their small size, high specific surface area, and strong biological penetration. Recently, there are increasing reports of numerous airborne microplastics, including polystyrene (PS), being detected in atmospheric samples, which implies a potential risk to the human respiratory system. In this work, we evaluated the effects of polystyrene nanoparticles of two different sizes (PS-NP25: 25 nm diameter and PS-NP70: 70 nm diameter) on the human alveolar epithelial A549 cell line including internalization, cell viability, cell cycle, apoptosis, and associated gene transcription and protein expression. Results showed that PS-NP25 was internalized more rapidly and efficiently into the cytoplasm of A549 than PS-NP70. PS-NPs significantly affected the cell viability, caused cell cycle S phrase arrest, activated inflammatory gene transcription, and changed the expression of proteins associated with cell cycle and pro-apoptosis. PS-NPs induced significant up-regulation of pro-inflammatory cytokines such as IL-8, NF-κB, and TNF-α, as well as pro-apoptotic proteins such as DR5, caspase-3, caspase-8, caspase-9, and cytochrome c, which revealed that PS-NPs triggered a TNF-α-associated apoptosis pathway. This study suggests that exposure duration, diameter, and concentration are the key factors for evaluating the toxicological effects of PS-NPs on alveolar epithelial cells. More attention must be focused on the risk of nanoplastic-related air pollution and the environmental toxicological effects of nanoplastics on humans and other terrestrial mammals.

Urban-associated diseases: Candidate diseases, environmental risk factors, and a path forward

BACKGROUND

Cities are home to over half the global population; that proportion is expected to rise to 70% by mid-century. The urban environment differs greatly from that in which humans evolved, with potentially important consequences for health. Rates for allergic, inflammatory and auto-immune diseases appear to rise with urbanization and be higher in the more urbanized nations of the world which has led some to suggest that cities promote the occurrence of these diseases. However, there are no syntheses outlining what urban-associated diseases are and what characteristics of cities promote their occurrence.

OBJECTIVES

To synthesize the current understanding of "urban-associated diseases", and discover the common, potentially modifiable features of cities that may be driving these associations.

METHODS

We focus on any diseases that have been associated with cities or are particularly prominent in today's urban societies. We draw on expertise across diverse health fields to examine the evidence for urban connections and drivers.

DISCUSSION

We found evidence for urban associations across allergic, auto-immune, inflammatory, lifestyle and infectious disease categories. Some conditions (e.g. obesity and diabetes) have complex relationships with cities that have been insufficiently explored. Other conditions (e.g. allergies and asthma) have more evidence demonstrating their relationship with cities and the mechanisms driving that association. Unsurprisingly, air pollution was the characteristic of cities most frequently associated with disease. Other identified urban risk factors are not as widely known: altered microbial exposure and a disconnect from environmental microbiomes, vitamin D deficiency, noise and light pollution, and a transient, over-crowded, impoverished population. However, many complexities and caveats to these relationships beg clarification; we highlight the current knowledge gaps and outline ways to fill those gaps. Identifying urban-associated diseases and their drivers will allow us to prepare for the urban-disease burden of the future and create healthy cities that mitigate that disease burden.

Associations between ambient air pollution and cancer incidence in Taiwan: an ecological study of geographical variations

BACKGROUND

Air pollution is a global public health concern. The World Health Organization has recently set up a goal of saving 7 million people globally by 2030 from air pollution related death. We conducted an ecological study of geographical variation to explore the association between air pollution (specifically, particulate matter <2.5 μm in aerodynamic diameter [PM2.5], particulate matter <10 μm in aerodynamic diameter, sulfur dioxide, nitrogen dioxide, nitric oxide, and ozone) and cancer incidence in Taiwan, from 2012 to 2016.

METHODS

In this study, the yearly average concentrations of each air pollutant at 75 air quality monitoring stations were calculated, and using the kriging method, the concentrations were extrapolated to each and every geographical central point of 349 local administrative areas of Taiwan. Spearman rank correlation coefficients between the age-adjusted cancer incidence rates and various air pollutants were calculated by stratifying genders and urbanization degrees of the local administrative areas. A total of 70 correlation coefficients were calculated.

RESULTS

In total, 17 correlation coefficients were significantly positive at an alpha level of 0.05. Among these, four correlation coefficients between the age-adjusted cancer incidence rates and PM2.5 levels remained significant after Bonferroni correction. For men in developing towns, general towns, and aged towns and for women in aged towns, the age-adjusted cancer incidence rates increased 13.1 (95% confidence interval [CI], 8.8-17.6), 11 (95% CI, 5.6-16.4), 16.7 (95% CI, 6.9-26.4), and 11.9 (95% CI, 5.6-18.2) per 100,000 populations, respectively, for every 1 μg/m3 increment in PM2.5 concentrations.

CONCLUSIONS

A significantly positive correlation was observed between the PM2.5 level and cancer incidence rate after multiple testing correction.

Characteristics of cohort studies of long-term exposure to PM2.5: a systematic review

This study systematically reviewed all the cohort studies investigating the relationship between long-term exposure to PM_2.5 and any health outcome until February 2018. We searched ISI Web of Knowledge, Pubmed, and Scopus databases for peer-reviewed journal research articles published in English. We only extracted the results of the single-pollutant main analysis of each study, excluding the effect modifications and sensitivity analyses. Out of the initial 9523 articles, 203 articles were ultimately included for analysis. Based on the different characteristics of studies such as study design, outcome, exposure assessment method, and statistical model, we calculated the number and relative frequency of analyses with statistically significant and insignificant results. Most of the studies were prospective (84.8%), assessed both genders (66.5%), and focused on a specific age range (86.8%). Most of the articles (78.1%) had used modeling techniques for exposure assessment of cohorts' participants. Among the total of 317 health outcomes, the most investigated outcomes include mortality due to cardiovascular disease (6.19%), all causes (5.48%), lung cancer (4.00%), ischemic heart disease (3.50%), and non-accidental causes (3.50%). The percentage of analyses with statistically significant results were higher among studies that used prospective design, mortality as the outcome, fixed stations as exposure assessment method, hazard ratio as risk measure, and no covariate adjustment. We can somehow conclude that the choice of right characteristics for cohort studies can make a difference in their results.

Occupational Exposure to Diesel and Gasoline Engine Exhausts and the Risk of Kidney Cancer in Canadian Men

Introduction

Kidney cancer is the fifth most common incident cancer in Canadian men. Diesel and gasoline exhausts are common workplace exposures that have been examined as risk factors for non-lung cancer sites, including the kidney, but limitations in exposure assessment methods have contributed to inconsistent findings. The objective of this study was to assess the relationship between occupational gasoline and diesel engine exhausts and the risk of kidney cancer in men.

Methods

The National Enhanced Cancer Surveillance System (NECSS) is a Canadian population-based case–control study conducted in 1994–1997. Incident kidney cancer cases were identified using provincial registries, while the control series was identified through random-digit dialing, or provincial administrative databases. Self-reported questionnaires were used to obtain information on lifetime occupational history and cancer risk factors. Two hygienists, blinded to case status, coded occupational histories for diesel and gasoline exhaust exposures using concentration, frequency, duration, and reliability. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) separately by exhaust type. The separate and combined impacts of both engine exhausts were also examined. ORs were adjusted for age, province, body mass index, occupational secondhand smoke exposure, and education.

Results

Of the kidney cancer cases (n = 712), 372 (52%) had exposure to both exhausts at some point, and 984 (40%) of the controls (n = 2457) were ever exposed. Workers who had ever been exposed to engine exhausts were more likely to have kidney cancer than those who were never exposed (OR diesel = 1.23, 95% CI = 0.99–1.53; OR gasoline = 1.51, 95% CI = 1.23–1.86). Exposure to gasoline exhaust was consistently associated with kidney cancer in a dose–response manner (P value for trends in highest attained and cumulative exposure both <0.0001). Those men with high cumulative exposure to both gasoline and diesel exhaust had a 76% increased odds of kidney cancer (95% CI = 1.27–2.43).

Conclusions

This study provides evidence that occupational gasoline, and to a lesser extent, diesel exhaust exposure may increase the risk of kidney cancer.

Spatial heterogeneity of KRAS mutations in colorectal cancers in northern France

Background

Somatic mutations in the KRAS gene are the most common oncogenic mutations found in human cancers. However, no clinical features have been linked to KRAS mutations in colorectal cancer [CRC].

Purpose

In this study, we attempted to identify the potential geographical population clusters of KRAS mutations in CRC patients in northern France.

Patients and methods

All patients with CRC who were identified to have KRAS mutations between 2008 and 2014 at the Regional Molecular Biology Platform at Lille University Hospital were included. 2,486 patients underwent a KRAS status available, with 40.9% of CRC with KRAS mutations in northern France. We retrospectively collected demographic and geographic data from these patients. The proportions of KRAS mutation were smoothed to take into account the variability related to low frequencies and spatial autocorrelation. Geographical clusters were searched using spatial scan statistical models.

Results

A mutation at KRAS codon 12 or 13 was found in 1,018 patients [40.9%]. We report 5 clusters of over-incidence but only one elongated cluster that was statistically significant [Cluster 1; proportion of KRAS mutation among CRC: 0.4570; RR=1.29; P=0.0314]. We made an ecological study which did not highlight a significant association between KRAS mutations and the distance to the Closest Waste Incineration Plant, and between KRAS mutations and The French Ecological Deprivation Index but few socio-economic and environmental data were available.

Conclusion

There was a spatial heterogeneity and a greater frequency of KRAS mutations in some areas close to major highways and big cities in northern France. These data demand deeper epidemiological investigations to identify environmental factors such as air pollution as key factors in the occurrence of KRAS mutations.

Role of Emerging Environmental Risk Factors in Thyroid Cancer: A Brief Review

Environmental factors are recognized as risk factors of thyroid cancer in humans. Exposure to radiation, both from nuclear weapon or fallout or medical radiation, and to some organic and inorganic chemical toxicants represent a worldwide public health issue for their proven carcinogenicity. Halogenated compounds, such as organochlorines and pesticides, are able to disrupt thyroid function. Polychlorinated biphenyls and their metabolites and polybrominated diethyl ethers bind to thyroid, transport proteins, replace thyroxin, and disrupt thyroid function as phthalates and bisphenolates do, highly mimicking thyroid hormones. A better knowledge of environmental risks represents a very important tool for cancer prevention through true risks prevention and management. This approach is very important because of the epigenetic origin’s theory of cancer. Therefore, the aim of this review was study the association between environmental agents and thyroid cancer promotion.

Interactive effects of changing stratospheric ozone and climate on tropospheric composition and air quality, and the consequences for human and ecosystem health

The composition of the air we breathe is determined by emissions, weather, and photochemical transformations induced by solar UV radiation. Photochemical reactions of many emitted chemical compounds can generate important (secondary) pollutants including ground-level ozone (O₃) and some particulate matter, known to be detrimental to human health and ecosystems. Poor air quality is the major environmental cause of premature deaths globally, and even a small decrease in air quality can translate into a large increase in the number of deaths. In many regions of the globe, changes in emissions of pollutants have caused significant changes in air quality. Short-term variability in the weather as well as long-term climatic trends can affect ground-level pollution through several mechanisms. These include large-scale changes in the transport of O₃ from the stratosphere to the troposphere, winds, clouds, and patterns of precipitation. Long-term trends in UV radiation, particularly related to the depletion and recovery of stratospheric ozone, are also expected to result in changes in air quality as well as the self-cleaning capacity of the global atmosphere. The increased use of substitutes for ozone-depleting substances, in response to the Montreal Protocol, does not currently pose a significant risk to the environment. This includes both the direct emissions of substitutes during use and their atmospheric degradation products (e.g. trifluoroacetic acid, TFA).

Air Pollution and Noncommunicable Diseases: A Review by the Forum of International Respiratory Societies' Environmental Committee, Part 2: Air Pollution and Organ Systems

Although air pollution is well known to be harmful to the lung and airways, it can also damage most other organ systems of the body. It is estimated that about 500,000 lung cancer deaths and 1.6 million COPD deaths can be attributed to air pollution, but air pollution may also account for 19% of all cardiovascular deaths and 21% of all stroke deaths. Air pollution has been linked to other malignancies, such as bladder cancer and childhood leukemia. Lung development in childhood is stymied with exposure to air pollutants, and poor lung development in children predicts lung impairment in adults. Air pollution is associated with reduced cognitive function and increased risk of dementia. Particulate matter in the air (particulate matter with an aerodynamic diameter < 2.5 μm) is associated with delayed psychomotor development and lower child intelligence. Studies link air pollution with diabetes mellitus prevalence, morbidity, and mortality. Pollution affects the immune system and is associated with allergic rhinitis, allergic sensitization, and autoimmunity. It is also associated with osteoporosis and bone fractures, conjunctivitis, dry eye disease, blepharitis, inflammatory bowel disease, increased intravascular coagulation, and decreased glomerular filtration rate. Atopic and urticarial skin disease, acne, and skin aging are linked to air pollution. Air pollution is controllable and, therefore, many of these adverse health effects can be prevented.

A global perspective on coal-fired power plants and burden of lung cancer

BACKGROUND

Exposure to ambient particulate matter generated from coal-fired power plants induces long-term health consequences. However, epidemiologic studies have not yet focused on attributing these health burdens specifically to energy consumption, impeding targeted intervention policies. We hypothesize that the generating capacity of coal-fired power plants may be associated with lung cancer incidence at the national level.

METHODS

Age- and sex-adjusted lung cancer incidence from every country with electrical plants using coal as primary energy supply were followed from 2000 to 2016. We applied a Poisson regression longitudinal model, fitted using generalized estimating equations, to estimate the association between lung cancer incidence and per capita coal capacity, adjusting for various behavioral and demographic determinants and lag periods.

RESULTS

The average coal capacity increased by 1.43 times from 16.01 gigawatts (GW) (2000~2004) to 22.82 GW (2010~2016). With 1 kW (KW) increase of coal capacity per person in a country, the relative risk of lung cancer increases by a factor of 59% (95% CI = 7.0%~ 135%) among males and 85% (95% CI = 22%~ 182%) among females. Based on the model, we estimate a total of 1.37 (range = 1.34 ~ 1.40) million standardized incident cases from lung cancer will be associated with coal-fired power plants in 2025.

CONCLUSIONS

These analyses suggest an association between lung cancer incidence and increased reliance on coal for energy generation. Such data may be helpful in addressing a key policy question about the externality costs and estimates of the global disease burden from preventable lung cancer attributable to coal-fired power plants at the national level.

Different trends in colorectal cancer mortality between age groups in China: an age-period-cohort and joinpoint analysis

OBJECTIVES

China is undergoing a rapid aging transition. The trends in age-specific mortality rates from colorectal cancer remain unknown, and a number of studies have not distinguished the age, period, and cohort effects simultaneously.

STUDY DESIGN

A descriptive study was implemented with a joinpoint regression analysis and age-period-cohort (APC) model based on the intrinsic estimator (IE).

METHODS

Age-specific mortality rates of colorectal cancer (1987-2016) were collected by gender (men/women) and region (urban/rural). The average annual percentage change (AAPC) and relative risks in the trend were identified using joinpoint Poisson regression and APC model (IE), respectively.

RESULTS

Joinpoint regression analysis revealed that the rates decreased in the younger (men aged <45 years and women aged <75 years) but increased in the older (men aged >75 years and women aged >80 years) age groups. The APC model (IE) showed that the rates increased with age and time period but decreased with birth cohorts. But from 2000 to 2005, the period effects showed a substantial decline among urban residents. From the 1910-1914 to the 1915-1919 birth cohort, mortality increased among men, and from the 1925-1929 to the 1930-1934 birth cohort, mortality increased among rural residents.

CONCLUSIONS

The trends in colorectal cancer mortality are different between age groups. The younger age groups show a decreasing trend, whereas the older age groups an increasing trend. Cost-effective prevention and control should be implemented more in the elderly and for older cohorts at high risk.

Long-Term Exposure to Air Pollutants and Cancer Mortality: A Meta-Analysis of Cohort Studies

The aim of this study was to examine the relationship between main air pollutants and all cancer mortality by performing a meta-analysis. We searched PubMed, EMBASE (a biomedical and pharmacological bibliographic database of published literature produced by Elsevier), and the reference lists of other reviews until April 2018. A random-effects model was employed to analyze the meta-estimates of each pollutant. A total of 30 cohort studies were included in the final analysis. Overall risk estimates of cancer mortality for 10 µg/m³ per increase of particulate matter (PM)2.5, PM10, and NO₂ were 1.17 (95% confidence interval (CI): 1.11⁻1.24), 1.09 (95% CI: 1.04⁻1.14), and 1.06 (95% CI: 1.02⁻1.10), respectively. With respect to the type of cancer, significant hazardous influences of PM2.5 were noticed for lung cancer mortality and non-lung cancer mortality including liver cancer, colorectal cancer, bladder cancer, and kidney cancer, respectively, while PM10 had harmful effects on mortality from lung cancer, pancreas cancer, and larynx cancer. Our meta-analysis of cohort studies indicates that exposure to the main air pollutants is associated with increased mortality from all cancers.

Pro-inflammatory effects of extracted urban fine particulate matter on human bronchial epithelial cells BEAS-2B

Atmospheric particulate matter (PM) constitutes the major part of urban air pollution and is a heterogeneous mixture of solid and liquid particles of different origin, size, and chemistry. Human exposure to PM in urban areas poses considerable and significant adverse effects on the respiratory system and human health in general. Major contributors to PM content are combustion-related sources such as diesel vehicles, household, and industrial heating. PM is composed of thousands of different high molecular weight organic compounds, including poly-aromatic hydrocarbons (PAHs). The aim of this study was to clarify the cytotoxic effects of the extract of actual urban PM1 with high benzo[a]pyrene (BaP) content collected in Eastern European mid-sized city during winter heating season on human bronchial epithelial cells (BEAS-2B). Decreased cell viability, alteration of cell layer integrity, increased apoptosis, and oxidative stress were observed during the 3-day exposure to the PM extract. In addition, following PM exposure pro-inflammatory cytokine expression was upregulated at gene and protein levels. Morphology and motility changes, i.e., decreased cells' ability to cover scratch area, were also documented. We report here that the extract of urban PM1 may induce bronchial epithelium changes and render it pro-inflammatory and compromised within 3 days.

Association between fine particulate matter and oral cancer among Taiwanese men

The aim of this study was to investigate the association between fine particulate matter 2.5 (PM_2.5) and oral cancer among Taiwanese men. Four linked data sources including the Taiwan Cancer Registry, Adult Preventive Medical Services Database, National Health Insurance Research Database, and Air Quality Monitoring Database were used. Concentrations of sulfur dioxide, carbon monoxide, ozone, NOx (nitrogen monoxide and nitrogen dioxide), coarse particulate matter (PM_10-2.5) and PM_2.5 in 2009 were assessed in quartiles. A total of 482 659 men aged 40 years and above were included in the analysis. Logistic regression was used to examine the association between PM_2.5 and oral cancer diagnosed from 2012 to 2013. After adjusting for potential confounders, the ORs of oral cancer were 0.91 (95% CI 0.75 to 1.11) for 26.74≤PM_2.5<32.37, 1.01 (95% CI 0.84 to 1.20) for 32.37≤PM_2.5<40.37 µg/m³ and 1.43 (95% CI 1.17 to 1.74) for PM_2.5≥40.37 µg/m³ compared with PM_2.5<26.74 µg/m³. In this study, there was an increased risk of oral cancer among Taiwanese men who were exposed to higher concentrations of PM_2.5.

The Kidney Injury Induced by Short-Term PM2.5 Exposure and the Prophylactic Treatment of Essential Oils in BALB/c Mice

PM_2.5 is well known as a major environmental pollutant; it has been proved to be associated with kidney diseases. The kidney damage involves oxidative stress and/or inflammatory response. NOX4 is a major source of reactive oxygen species (ROS) generation in the kidney, and the excessive generation of ROS is recognized to be responsible for oxidative stress. To elucidate whether short-term PM_2.5 exposure could induce kidney damage, we exposed BALB/c mice to PM_2.5 intratracheally and measured the biomarkers of kidney injury (KIM-1, cystatin C), oxidative stress (MDA, SOD-1, and HO-1), and inflammatory response (NF-κB, TNF-α). Acute kidney damage and excessive oxidative stress as well as transient inflammatory response were observed after PM_2.5 installation. The overexpression of some components of the angiotensin system (RAS) after PM_2.5 exposure illustrated that RAS may be involved in PM_2.5-induced acute kidney injury. CEOs (compound essential oils) have been widely used because of their antioxidant and anti-inflammation properties. Treatment with CEOs substantially attenuated PM_2.5-induced acute kidney injury. The suppression of RAS activation was significant and earlier than the decrease of oxidative stress and inflammatory response after CEOs treatment. We hypothesized that CEOs could attenuate the acute kidney injury by suppressing the RAS activation and subsequently inhibit the oxidative stress and inflammatory response.

Effects of exposure estimation errors on estimated exposure-response relations for PM2.5

Associations between fine particulate matter (PM2.5) exposure concentrations and a wide variety of undesirable outcomes, from autism and auto theft to elderly mortality, suicide, and violent crime, have been widely reported. Influential articles have argued that reducing National Ambient Air Quality Standards for PM2.5 is desirable to reduce these outcomes. Yet, other studies have found that reducing black smoke and other particulate matter by as much as 70% and dozens of micrograms per cubic meter has not detectably affected all-cause mortality rates even after decades, despite strong, statistically significant positive exposure concentration-response (C-R) associations between them. This paper examines whether this disconnect between association and causation might be explained in part by ignored estimation errors in estimated exposure concentrations. We use EPA air quality monitor data from the Los Angeles area of California to examine the shapes of estimated C-R functions for PM2.5 when the true C-R functions are assumed to be step functions with well-defined response thresholds. The estimated C-R functions mistakenly show risk as smoothly increasing with concentrations even well below the response thresholds, thus incorrectly predicting substantial risk reductions from reductions in concentrations that do not affect health risks. We conclude that ignored estimation errors obscure the shapes of true C-R functions, including possible thresholds, possibly leading to unrealistic predictions of the changes in risk caused by changing exposures. Instead of estimating improvements in public health per unit reduction (e.g., per 10 µg/m³ decrease) in average PM2.5 concentrations, it may be essential to consider how interventions change the distributions of exposure concentrations.

Rural-urban inequities in deaths and cancer mortality amid rapid economic and environmental changes in China

OBJECTIVES

This paper examines rural-urban inequities in mortality and cancer mortality amid rapid economic growth and environmental degradation in China.

METHODS

SPSS and Joinpoint Regression were used to analyze the 2002-2015 datasets from all death registries in China and associated economic and environmental data.

RESULTS

Death and cancer mortality rates among rural residents were higher and increased faster than urban residents. In particular, rural men 30-34 years old were 44% more likely to die from cancer and over 67% more likely to die from all causes, compared to their urban counterparts. Among rural women 15-19 years old, the death rate was 47% higher and the cancer mortality rate was 44% higher than among urban women. Death and cancer mortality rates tended to be positively associated with economic growth and air pollution variables.

CONCLUSIONS

Rural-urban health inequities have widened in China, with rural youth at the greatest disadvantage. The anticipated health benefits from income growth may have been offset by the impact of air pollution, which calls for further investigation into the causes of rural-urban health inequities.

Air pollution from industrial waste gas emissions is associated with cancer incidences in Shanghai, China

Outdoor air pollution may be associated with cancer risk at different sites. This study sought to investigate outdoor air pollution from waste gas emission effects on multiple cancer incidences in a retrospective population-based study in Shanghai, China. Trends in cancer incidence for males and females and trends in waste gas emissions for the total waste gas, industrial waste gas, other waste gas, SO₂, and soot were investigated between 1983 and 2010 in Shanghai, China. Regression models after adjusting for confounding variables were constructed to estimate associations between waste gas emissions and multiple cancer incidences in the whole group and stratified by sex, Engel coefficient, life expectancy, and number of doctors per 10,000 populations to further explore whether changes of waste gas emissions were associated with multiple cancer incidences. More than 550,000 new cancer patients were enrolled and reviewed. Upward trends in multiple cancer incidences for males and females and in waste gas emissions were observed from 1983 to 2010 in Shanghai, China. Waste gas emissions came mainly from industrial waste gas. Waste gas emissions was significantly positively associated with cancer incidence of salivary gland, small intestine, colorectal, anus, gallbladder, thoracic organs, connective and soft tissue, prostate, kidney, bladder, thyroid, non-Hodgkin's lymphoma, lymphatic leukemia, myeloid leukemia, and other unspecified sites (all p < 0.05). Negative association between waste gas emissions and the esophagus cancer incidence was observed (p < 0.05). The results of the whole group were basically consistent with the results of the stratified analysis. The results from this retrospective population-based study suggest ambient air pollution from waste gas emissions was associated with multiple cancer incidences.