Long-term concentrations of ambient air pollutants and incident lung cancer in California adults: results from the AHSMOG study.Adventist Health Study on Smog

Greenness, air pollution, and mortality risk: a retrospective cohort study of patients with lung cancer in China

The association between long-term exposure to air pollution and mortality from lung cancer has been established, yet evaluations of the potential mitigating effects of greenness on this impact are scarce. We conducted a cohort study in Pingyi County. A two-level Cox proportional hazards regression model was used to examine the associations among long-term exposure to air pollution, residential greenness, and lung cancer mortality. Among the examined pollutants, nitrogen dioxide exhibited the most significant adverse effects and highest risk of lung cancer mortality, with hazard ratio (HR) = 2.783 (95% confidence interval [CI]: 1.885-4.107) for all-cause mortality, HR = 2.492 (95%CI: 1.659-3.741) for tumour-related mortality, and HR = 2.431 (95%CI: 1.606-3.678) for lung cancer mortality. Higher greenness values were associated with a reduced risk of lung cancer mortality. These findings suggest the importance of implementing strategies for increasing greenness to reduce the health impacts of air pollution.

Racial Disparities in Head and Neck Cancer: It's Not Just About Access

OBJECTIVE

Medical literature identifies stark racial disparities in head and neck cancer (HNC) in the United States, primarily between non-Hispanic white (NHW) and non-Hispanic black (NHB) populations. The etiology of this disparity is often attributed to inequitable access to health care and socioeconomic status (SES). However, other contributors have been reported. We performed a systematic review to better understand the multifactorial landscape driving racial disparities in HNC.

DATA SOURCES

A systematic review was conducted in Covidence following Preferred Reporting Items for Systematic Reviews and Meta-analyses Guidelines. A search of PubMed, SCOPUS, and CINAHL for literature published through November 2022 evaluating racial disparities in HNC identified 2309 publications.

REVIEW METHODS

Full texts were screened by 2 authors independently, and inconsistencies were resolved by consensus. Three hundred forty publications were ultimately selected and categorized into themes including disparities in access/SES, treatment, lifestyle, and biology. Racial groups examined included NHB and NHW patients but also included Hispanic, Native American, and Asian/Pacific Islander patients to a lesser extent.

RESULTS

Of the 340 articles, 192 focused on themes of access/SES, including access to high-quality hospitals, insurance coverage, and transportation contributing to disparate HNC outcomes. Additional themes discussed in 148 articles included incongruities in surgical recommendations, tobacco/alcohol use, human papillomavirus-associated malignancies, and race-informed silencing of tumor suppressor genes.

CONCLUSION

Differential access to care plays a significant role in racial disparities in HNC, disproportionately affecting NHB populations. However, there are other significant themes driving racial disparities. Future studies should focus on providing equitable access to care while also addressing these additional sources of disparities in HNC.

Does the Level of Air Pollution Affect the Incidence of Lung Adenocarcinoma in South-Eastern Poland?

The aim of this study was to assess the association of long-term exposure to particulate matter with aerodynamic diameter, PM2.5, PM10, NO2 and SO2 as well as CO, with lung adenocarcinoma (AD) in south-east Poland for the years from 2004 to 2014. The study group consisted of 4296 patients with lung adenocarcinoma and the level of selected pollutants. To analyse the data, a standard statistics for cohort data, that is a risk ratio (RR), was used. The dependencies occurring in the distribution of pollutants and cancer incidence were examined using Moran's I correlation coefficient. The current study suggests that PM10, NO2 and SO2 exposure as an air pollutant may increase female lung adenocarcinoma incidence. In men, the increased risk of adenocarcinoma lung cancer is affected by SO2 and PM10. A high morbidity rate in urban areas and suburbs may be connected with commuting from moderately polluted living areas to highly polluted working areas.

Health effects of exposure to sulfur dioxide, nitrogen dioxide, ozone, and carbon monoxide between 1980 and 2019: A systematic review and meta-analysis

The burden of disease attributed to the indoor exposure to sulfur dioxide (SO₂ ), nitrogen dioxide (NO₂ ), ozone (O₃ ), and carbon monoxide (CO) is not clear, and the quantitative concentration-response relationship is a prerequisite. This is a systematic review to summarize the quantitative concentration-response relationships by screening and analyzing the polled effects of population-based epidemiological studies. After collecting literature published between 1980 and 2019, a total of 19 health outcomes in 101 studies with 182 health risk estimates were recruited. By meta-analysis, the leave-one-out sensitivity analysis and Egger's test for publication bias, the robust and reliable effects were found for SO₂ (per 10 μg/m³ ) with chronic obstructive pulmonary diseases (COPD) (pooled relative risks [RRs] 1.016, 95% CI: 1.012-1.021) and cardiovascular diseases (CVD) (RR 1.012, 95%CI: 007-1.018), respectively. NO₂ (per 10 μg/m³ ) had the pooled RRs for childhood asthma, preterm birth, lung cancer, diabetes, and COPD by 1.134 (1.084-1.186), 1.079 (1.007-1.157), 1.055 (1.010-1.101), 1.019 (1.009-1.029), and 1.016 (1.012-1.120), respectively. CO (per 1 mg/m³ ) was significantly associated with Parkinson's disease (RR 1.574, 95% CI: 1.069-2.317) and CVD (RR 1.024, 95% CI: 1.011-1.038). No robust effects were observed for O₃ . This study provided evidence and basis for further estimation of the health burden attributable to the four gaseous pollutants.

Identification of the Major Product of Guanine Oxidation in DNA by Ozone

Ozonolysis of guanosine formed the 5-carboxamido-5-formamido-2-iminohydantoin (2Ih) nucleoside along with trace spiroiminodihydantoin (Sp). On the basis of literature precedent, we propose an unconventional ozone mechanism involving incorporation of only one oxygen atom of O₃ to form 2Ih with evolution of singlet oxygen responsible for Sp formation. The increased yield of Sp in the buffered ¹O₂-stabilizing solvent D₂O, formation of 2Ih in a short oligodeoxynucleotide, and ¹⁸O-isotope labeling provided evidence to support this mechanism. The elusiveness and challenges of working with 2Ih are described in a series of studies on the significant context effects on the half-life of the 2Ih glycosidic bond.

Health impact assessment from exposure to trace metals present in atmospheric PM10 at Ahmedabad, a big city in western India

Many toxicological studies revealed the deleterious effects on human health induced by trace metals in ambient particulate matter (PM). This study reports the season-dependent water-soluble and total metal mass in PM₁₀ collected simultaneously over five microenvironments in a semi-arid urban region, Ahmedabad, located in western India. The mineral dust fraction in PM₁₀ over Bapunagar, Narol, Paldi, Income Tax, and Science City was estimated to be around 39, 45, 47, 44, and 31% during summer (May-June 2017) and 24, 55, 28, 27, and 28% during winter (December 2017-January 2018), respectively, corroborating mineral dust is perennial in the air over Ahmedabad. The PM_2.5/PM₁₀ mass ratios over all the sites were higher during winter (40-60%) as compared to those during summer (30-40%), indicating the contribution from the anthropogenic sources to PM mass. Among the metals monitored, the estimated considerable amount of high masses of Zn, Cu, Ni, Cd, and Sb during winter can be ascribed to the anthropogenic inputs based on the estimated enrichment factors (EF). In contrast to the crustal source, these metals might have been possibly emitted from several other man-made sources, which were found to be more water-soluble during both seasons. As per the standards of incremental excess lifetime cancer risk (IELCR), it is estimated that the atmospheric mass concentration of carcinogenic metals such as Cr, Co, and As was higher in all these sites, whereas the metals such as Pb, Ni, and Cd are also found over the industrial site (Narol) in addition to the above-said metals. Notably, people are highly susceptible to these metals, leading to the potential risk of cancer during both seasons.

Severe Air Pollution and Psychological Distress in China: The Interactive Effects of Coping and Perceived Controllability

The coping styles of focusing on a stressor (i.e., trauma focus), and moving beyond the emotional impact of a stressor (i.e., forward focus), have both been found beneficial to psychological adjustment. This study investigated whether these two coping styles are similarly associated with adjustment across levels of perceived controllability and beyond European-American contexts. During China’s peak of air pollution in 2014, we surveyed 250 young- to middle- aged adults online to measure their coping behaviors, smog perceptions, and psychological distress, and collected objective data of pollution severity in the respondents’ cities. Results showed that forward-focus coping was generally associated with lower distress and trauma-focus coping was associated with greater distress. Perceived controllability significantly moderated the associations between trauma focus (but not forward focus) and distress. These findings suggest that while forward focus correlated with beneficial adjustment outcomes in coping with air pollution, the extensive processing of event-related cognitions and emotions in trauma focus may be detrimental, especially for events perceived to be less controllable. We discussed the implications of our findings within an interdependent cultural context.

Micro-Reactor System for Complete Oxidation of Volatile Organic Compounds

Based on previous Computational Fluid Dynamics (CFD) design results, an 11 channel microreactor of dimensions (0.5 mm × 0.5 mm × 100 mm) (width × depth × length) and optimal manifold geometry was fabricated, coated with a newly-developed Au/SBA-15 catalyst and then integrated in an experimental rig specifically built for this research. Propane (as model volatile organic compound) oxidation experiments were conducted at three different flow velocities, 12.5, 15.4 and 17.5 m/min, respectively, at six temperatures, 150, 200, 225, 250, 275, and 300 °C, respectively. The catalyst was prepared by one-pot sol-gel synthesis of SBA-15 with MPTMS (3-mercaptopropyl-trimethoxy-silane) before loading with HAuCl4 gold precursor and then characterized by SEM/EDX, TEM and wide angle XRD. A novel catalyst coating technique was developed, using airbrush (0.3 nozzle) to spray a catalyst slurry into the microchannels that produced a thin, firm and uniform layer of Au/SBA-15 catalyst coating inside the microreactor. The experimental measurements revealed that propane conversion increased as the flow feed rates decreased and increased with increasing temperatures in the reactor. For the built microreactor and for the flows and temperatures set, the combustion of propane was possible with measurable conversions and reasonable reactor stability, the performance of the catalyst appeared to be central to the satisfactory operation of the reactor.

Epidemiology of Lung Cancer

Lung cancer has been transformed from a rare disease into a global problem and public health issue. The etiologic factors of lung cancer become more complex along with industrialization, urbanization, and environmental pollution around the world. Currently, the control of lung cancer has attracted worldwide attention. Studies on the epidemiologic characteristics of lung cancer and its relative risk factors have played an important role in the tertiary prevention of lung cancer and in exploring new ways of diagnosis and treatment. This article reviews the current evolution of the epidemiology of lung cancer.

International trends in lung cancer incidence from 1973 to 2007

Lung cancer is the commonly diagnosed cancer and one of the most important avoidable causes of death around the world. We conducted the study to investigate the pattern of lung cancer incidence worldwide. Joinpoint analysis was used to extend international lung cancer incidence rates by the latest data from Cancer Incidence in Five Continents over the 35‐year period 1973–2007 from 24 populations from Americas, Asia, Europe, and Oceania. Age‐standardized incidence rates (ASRs) of lung cancer were from 33.3 to 66.8 per 100,000 among males and 10.5 to 37.4 per 100,000 among females in most of Americas, Europe, and Oceania populations during the period 2003–2007. In Asia, ASRs in China (Hong Kong) were the highest, up to 53.3 per 100,000 in males and 21.9 per 100,000 in females during the period 2003–2007. The international trends between 1973 and 2007 showed that ASRs of lung cancer among males were declining in 13 of 18 selected Americas, Oceania, and Europe populations, with AAPC from −0.7% to −2.9%, whereas the rates among females in 18 selected populations were increasing, with AAPC from 1.3% to 5.0%. The increasing and decreasing trends of ASRs of lung cancer in Asia have a geographic variation but no gender differences. Although the decreasing trends in ASRs of lung cancer for males were observed, the ASRs were higher than females. The declining trends in males were mainly attributed to tobacco control, whereas the increasing trends in females should be given more concern and need to be further studied in etiology factors.

Lung Cancer Risk and Residential Exposure to Air Pollution: A Korean Population-Based Case-Control Study

PURPOSE

To investigate the association between long-term exposure to ambient air pollution and lung cancer incidence in Koreans.

MATERIALS AND METHODS

This was a population-based case-control study covering 908 lung cancer patients and 908 controls selected from a random sample of people within each Korean province and matched according to age, sex, and smoking status. We developed land-use regression models to estimate annual residential exposure to particulate matter (PM₁₀) and nitrogen dioxide (NO₂) over a 20-year exposure period. Logistic regression was used to estimate odds ratios (ORs) and their corresponding 95% confidence intervals (CI).

RESULTS

Increases in lung cancer incidence (expressed as adjusted OR) were 1.09 (95% CI: 0.96-1.23) with a ten-unit increase in PM₁₀ (μg/m³) and 1.10 (95% CI: 1.00-1.22) with a ten-unit increase in NO₂ (ppb). Tendencies for stronger associations between air pollution and lung cancer incidence were noted among never smokers, among those with low fruit consumption, and among those with a higher education level. Air pollution was more strongly associated with squamous cell and small cell carcinomas than with adenocarcinoma of the lung.

CONCLUSION

This study provides evidence that PM10 and NO₂ contribute to lung cancer incidence in Korea.

Two-Photon and Deep-Red Emission Ratiometric Fluorescent Probe with a Large Emission Shift and Signal Ratios for Sulfur Dioxide: Ultrafast Response and Applications in Living Cells, Brain Tissues, and Zebrafishes

Sulfur dioxide (SO₂) is a dangerous environmental pollutant. Excessive intake of it may cause some respiratory diseases and even lung cancer. The development of effective methods for detection of SO₂ is of great importance for the environment and physiology. Herein, we have designed and synthesized a novel two-photon (TP) and deep-red emission ratiometric fluorescent probe (CP) for detection of SO₂. Notably, the novel probe CP exhibited ultrafast response to SO₂ in less than 5 s and displayed a great emission shift (195 nm) and a large emission signal ratio variation (enhancement from 0.1347 to 100.14). In addition, the unique probe was successfully employed for imaging SO₂ not only in the mitochondria of living cells but also in brain tissues and zebrafishes.

The association between ambient fine particulate matter and incident adenocarcinoma subtype of lung cancer

BACKGROUND

Adenocarcinoma (AC) is the most common lung cancer among non-smokers, but few studies have assessed the effect of PM_2.5 on AC among never smokers. The purpose of this study was to assess the association between ambient PM_2.5 and incident lung AC in the Adventist Health and Smog Study-2 (AHSMOG-2), a cohort of 80,044 non-smokers (81% never smokers) followed for 7.5 years (597,177 person-years) (2002-2011).

METHODS

Incident lung AC was identified through linkage with U.S. state cancer registries. Ambient PM_2.5 levels at subjects' residences were estimated for the years 2000 and 2001, immediately prior to study start.

RESULTS

A total of 164 incident lung AC occurred during follow-up. Each 10 μg/m³ increment in PM_2.5 was associated with an increase in the hazard rate of lung AC [HR = 1.31 (95% confidence interval (CI) 0.87-1.97)] in the single-pollutant model. Excluding those with prevalent non-melanoma skin cancer (NMSC) strengthened the association with lung AC (HR = 1.62 (95% CI, 1.11-2.36) for each 10 μg/m³ PM_2.5 increment. Also, limiting the analyses to subjects who spent more than 1 h/day outdoors, increased the estimate (HR = 1.55, 95% CI: 1.05, 2.30).

CONCLUSIONS

Increased risk of AC was observed for each 10 μg/m³ increment in ambient PM_2.5 concentrations. The risk was higher among those without prevalent NMSC and those who spent more than 1 h/day outdoors.

The association of remotely sensed outdoor fine particulate matter with cancer incidence of respiratory system in the USA

This study aimed to assess the association between exposure to fine particulate matter (PM_2.5) and respiratory system cancer incidence in the US population (n = 295,404,580) using a satellite-derived estimate of PM_2.5 concentrations. Linear and logistic regression analyses were performed to determine whether PM_2.5 was related to the odds of respiratory system cancer (RSC) incidence based on gender and race. Positive linear regressions were found between PM_2.5 concentrations and the age-adjusted RSC incidence rates for all groups (Males, Females, Whites, and Blacks) except for Asians and American Indians. The linear relationships between PM_2.5 and RSC incidence rate per 1 μg/m³ PM_2.5 increase for Males, Females, Whites, Blacks, and all categories combined had slopes of, respectively, 7.02 (R² = 0.36), 2.14 (R² = 0.14), 3.92 (R² = 0.23), 5.02 (R² = 0.21), and 4.15 (R² = 0.28). Similarly, the logistic regression odds ratios per 10 μg/m³ increase of PM_2.5 were greater than one for all categories except for Asians and American Indians, indicating that PM_2.5 is related to the odds of RSC incidence. The age-adjusted odds ratio for males (OR = 2.16, 95% CI = 1.56-3.01) was higher than that for females (OR = 1.50, 95% CI = 1.09-2.06), and it was higher for Blacks (OR = 2.12, 95% CI = 1.43-3.14) than for Whites (OR = 1.72, 95% CI = 1.23-2.42). The odds ratios for all categories were attenuated with the inclusion of the smoking covariate, reflecting the effect of smoking on RSC incidence besides PM_2.5.

Perception of Air Pollution in the Jinchuan Mining Area, China: A Structural Equation Modeling Approach

Studies on the perception of air pollution in China are very limited. The aim of this paper is to help to fill this gap by analyzing a cross-sectional dataset of 759 residents of the Jinchuan mining area, Gansu Province, China. The estimations suggest that perception of air pollution is two-dimensional. The first dimension is the perceived intensity of air pollution and the second is the perceived hazardousness of the pollutants. Both dimensions are influenced by environmental knowledge. Perceived intensity is furthermore influenced by socio-economic status and proximity to the pollution source; perceived hazardousness is influenced by socio-economic status, family health experience, family size and proximity to the pollution source. There are no reverse effects from perception on environmental knowledge. The main conclusion is that virtually all Jinchuan residents perceive high intensity and hazardousness of air pollution despite the fact that public information on air pollution and its health impacts is classified to a great extent. It is suggested that, to assist the residents to take appropriate preventive action, the local government should develop counseling and educational campaigns and institutionalize disclosure of air quality conditions. These programs should pay special attention to young residents who have limited knowledge of air pollution in the Jinchuan mining area.

Human and Environmental Dangers Posed by Ongoing Global Tropospheric Aerosolized Particulates for Weather Modification

BACKGROUND

U.S. military perception of nuclear warfare led to countless unethical nuclear experiments performed on unsuspecting individuals without their informed consent. As evidenced here, subsequent perception of weather warfare has led to exposing millions of unsuspecting individuals to toxic coal fly ash with no public disclosure, no informed consent, and no health warnings.

METHODS

Three methods were used: (1) comparison of eight elements analyzed in rainwater samples, thought to have leached from aerosolized coal fly ash, with corresponding coal fly ash laboratory leachate; (2) comparison of 14 elements analyzed in air filter dust with corresponding elements in coal fly ash; and (3) comparison of 23 elements analyzed in fibrous mesh found after snow melted with corresponding elements in coal fly ash.

RESULTS

The rainwater element ratios show that the aerial particulate matter has essentially the same water-leach characteristics as coal fly ash. The air filter dust element ratios occur in the same range of compositions as coal fly ash, as do element ratios in fibrous mesh found on grass after snow melted. The fibrous mesh provides an inferred direct connection with the aerosolizing jet aircraft via coal fly ash association with the jet combustion environment.

CONCLUSION

Strong evidence for the correctness of the hypothesis: coal fly ash is likely the aerosolized particulate emplaced in the troposphere for geoengineering, weather modification, and/or climate alteration purposes. The documented public health associations for ≤2.5 μm particulate pollution are also applicable to aerosolized coal fly ash. The ability of coal fly ash to release aluminum in a chemically mobile form upon exposure to water or body moisture has potentially grave human and environmental consequences over a broad spectrum, including implications for neurological diseases and biota debilitation. The ability of coal fly ash to release heavy metals and radioactive elements upon exposure to body moisture has potentially grave human health implications including cancer, cardiovascular disease, diabetes, respiratory diseases, reduced male fertility, and stroke. The fibrous mesh data admit the possibility of environmentally disastrous formation of methylmercury and ozone-depleting chlorinated-fluorinated hydrocarbons in jet exhaust. Geophysical implications include atmospheric warming and rainfall retardation.

An ecological analysis of PM2.5 concentrations and lung cancer mortality rates in China

OBJECTIVE

To explore the association between Particulate Matter (PM)2.5 (particles with an aerodynamic diameter less than 2.5 µm) and lung cancer mortality rates and to estimate the potential risk of lung cancer mortality related to exposure to high PM2.5 concentrations.

DESIGN

Geographically weighted regression was performed to evaluate the relation between PM2.5 concentrations and lung cancer mortality for males, females and for both sexes combined, in 2008, based on newly available long-term data. Lung cancer fatalities from long-term exposure to PM2.5 were calculated according to studies by Pope III et al and the WHO air quality guidelines (AQGs).

SETTING

31 provinces in China.

RESULTS

PM2.5 was associated with the lung cancer mortality of males, females and both sexes combined, in China, although there were exceptions in several regions, for males and females. The number of lung cancer fatalities calculated by the WHO AQGs ranged from 531,036 to 532,004, whereas the number calculated by the American Cancer Society (ACS) reached 614,860 after long-term (approximately 3-4 years) exposure to PM2.5 concentrations since 2008.

CONCLUSIONS

There is a positive correlation between PM2.5 and lung cancer mortality rate, and the relationship between them varies across the entire country of China. The number of lung cancer fatalities estimated by ACS was closer to the actual data than those of the WHO AQGs. Therefore, the ACS estimate of increased risk of lung cancer mortality from long-term exposure to PM2.5 might be more applicable for evaluating lung cancer fatalities in China than the WHO estimate.

Traffic-related air pollution and lung cancer: A meta-analysis

Background

We conducted a meta-analysis to evaluate the association between traffic-related air pollution and lung cancer in order to provide evidence for control of traffic-related air pollution.

Methods

Several databases were searched for relevant studies up to December 2013. The quality of articles obtained was evaluated by the Strengthening the Reporting of Observational Studies in Epidemiology checklist. Statistical analysis, including pooling effective sizes and confidential intervals, was performed.

Results

A total of 1106 records were obtained through the database and 36 studies were included in our analysis. Among the studies included, 14 evaluated the association between ambient exposure to traffic-related air pollution and lung cancer and 22 studies involved occupational exposure to air pollution among professional drivers. Twenty-two studies were marked A level regarding quality, 13 were B level, and one was C level. Exposure to nitrogen dioxide (meta-odds ratio [OR]: 1.06, 95% confidence interval [CI]: 0.99–1.13), nitrogen oxide (meta-OR: 1.04, 95% CI: 1.01–1.07), sulfur dioxide (meta-OR: 1.03, 95% CI: 1.02–1.05), and fine particulate matter (meta-OR: 1.11, 95% CI: 1.00–1.22) were positively associated with a risk of lung cancer. Occupational exposure to air pollution among professional drivers significantly increased the incidence (meta-OR: 1.27, 95% CI: 1.19–1.36) and mortality of lung cancer (meta-OR: 1.14, 95% CI: 1.04–1.26).

Conclusion

Exposure to traffic-related air pollution significantly increased the risk of lung cancer.

Levels of PM2.5/PM10 and associated metal(loid)s in rural households of Henan Province, China

Although a majority of China's rural residents use solid fuels (biomass and coal) for household cooking and heating, clean energy such as electricity and liquid petroleum gas is becoming more popular in the rural area. Unfortunately, both solid fuels and clean energy could result in indoor air pollution. Daily respirable particulate matter (PM≤10 μm) and inhalable particulate matter (PM≤2.5 μm) were investigated in kitchens, sitting rooms and outdoor area in rural Henan during autumn (Sep to Oct 2012) and winter (Jan 2013). The results showed that PM (PM2.5 and PM10) and associated metal(loid)s varied among the two seasons and the four types of domestic energy used. Mean concentrations of PM2.5 and PM10 in kitchens during winter were 59.2-140.4% and 30.5-145.1% higher than those during autumn, respectively. Similar with the trends of PM2.5 and PM10, concentrations of As, Pb, Zn, Cd, Cu, Ni and Mn in household PM2.5 and PM10 were apparently higher in winter than those in autumn. The highest mean concentrations of PM2.5 and PM10 (368.5 and 588.7 μg m(-3)) were recorded in sitting rooms in Baofeng during winter, which were 5.7 and 3.9 times of corresponding health based guidelines for PM2.5 and PM10, respectively. Using coal can result in severe indoor air pollutants including PM and associated metal(loid)s compared with using crop residues, electricity and gas in rural Henan Province. Rural residents' exposure to PM2.5 and PM10 would be roughly reduced by 13.5-22.2% and 8.9-37.7% via replacing coal or crop residues with electricity. The present study suggested that increased use of electricity as domestic energy would effectively improve indoor air quality in rural China.

Ambient particulate matter and lung cancer incidence and mortality: a meta-analysis of prospective studies

BACKGROUND

Chronic exposure to ambient particulate matter (PM) has been suggested to be associated with an increased risk of lung cancer, but the results were inconsistent. We performed a systematic review and meta-analysis of prospective studies to assess the association between exposure to PM and the incidence and mortality of lung cancer in adults.

METHODS

We searched PUBMED and EMBASE databases for prospective cohort studies that evaluated the association between PM2.5 (diameter < 2.5 μm), PM10 (diameter < 10 μm) and lung cancer incidence and mortality. Relative risks (RRs) and 95% confidence interval (CI) were calculated using fixed-effect or random-effects models when appropriate.

RESULTS

We initially identified 1987 citations, and 19 prospective cohort studies were finally included in our meta-analysis. The pooled adjusted RRs for lung cancer mortality were 1.09 (95% CI: 1.06-1.11; I(2) = 18.3%, P = 0.26) for 10 µg/m(3) increase in the concentration of PM2.5 (12 studies), and 1.05 (95% CI: 1.03-1.07; I(2) = 41.9%, P = 0.11) for 10 µg/m(3) increase in the concentration of PM10 (seven studies). The increased risk of lung cancer mortality associated with PM2.5 and PM10 was consistent across most subgroups. PM10 (three studies) and PM2.5 (two studies) were not found to be significantly associated with lung cancer incidence.

CONCLUSIONS

Ambient PM2.5 and PM10 pollutions are prospectively associated with a significantly increased risk of lung cancer mortality. More studies addressing the association between PM and lung cancer incidence are required.

Characteristics of particulate matter (PM10) and its relationship with meteorological factors during 2001-2012 in Beijing

Atmospheric pollution has become a significant challenge in Beijing metropolitan region, China. In this study, wavelet analysis and gray analysis were proposed to explore the temporal characteristics of particulate matter (PM10) and its relationships with meteorological factors during 2001-2012. The analysis indicated that air quality had got better significantly over the last decade. It was clearly interannual, seasonal, and monthly variation of atmospheric pollution, which represented that the air quality was the worst in spring, and got better in summer, subsequently tended to be more serious in autumn and winter. Generally atmospheric pressure was the most important meteorological feature influencing on PM10, followed by relative humidity and wind speed. However, the dominant meteorological factors influencing the atmospheric pollution were different in the four seasons. The results suggest that urban design and effective measures based on the relationship between meteorological factors and PM10 would be effective for improving atmospheric pollution.

Oxidative capacities of size-segregated haze particles in a residential area of Beijing

The frequent haze days around the Chinese capital of Beijing in recent years have aroused great attention owing to the detrimental effects on visibility and public health. To discover the potential health effects of the haze, oxidative capacities of airborne particles collected in Beijing during haze and clear days were comparably assessed by a plasmid scission assay. Eleven water-soluble trace elements (As, Cd, Cr, Cu, Mn, Ni, Pb, V, Se, Tl, and Zn) in the size-segregated airborne particles were quantitatively analyzed by inductively coupled plasma mass spectrometry, and most of the water-soluble trace elements were found to mainly concentrate in the fine particle size of 0.56-1.0 microm. In comparison with clear days, the mass concentrations of 11 analyzed water-soluble trace elements remarkably increased during haze days, and the oxidative capacities determined by the plasmid scission assay were markedly elevated accordingly during the haze days under the same dosage of particles as for those during clear days. Water-soluble trace elements in airborne particles, such as Cu, V, and particularly Zn, were found to have significantly positive correlations with the plasmid DNA damage rates. Because Cu, V, and Zn have been considered as bioavailable elements, the evident increase of these elements during haze days may be greatly harmful to human health.

Long-term residential exposure to air pollution and lung cancer risk

BACKGROUND

There is accumulating evidence that air pollution causes lung cancer. Still, questions remain about exposure misclassification, the components of air pollution responsible, and the histological subtypes of lung cancer that might be produced.

METHODS

We investigated lung cancer incidence in relation to long-term exposure to three ambient air pollutants and proximity to major roads, using a Canadian population-based case-control study. We compared 2,390 incident, histologically confirmed lung cancer cases with 3,507 population controls in eight Canadian provinces from 1994 to 1997. We developed spatiotemporal models for the whole country to estimate annual residential exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) over a 20-year exposure period. We carried out a subanalysis in urban centers, using exposures derived from fixed-site air pollution monitors, and also examined traffic proximity measures. Hierarchical logistic regression models incorporated a comprehensive set of individual and geographic covariates.

RESULTS

The increase in lung cancer incidence (expressed as fully adjusted odds ratios [ORs]) was 1.29 (95% confidence interval = 0.95-1.76) with a ten-unit increase in PM2.5 (μg/m), 1.11 (1.00-1.24) with a ten-unit increase in NO2 (ppb), and 1.09 (0.85-1.39) with a ten-unit increase in O3 (ppb). The urban monitor-based subanalyses generally supported the national results, with larger associations for NO2 (OR = 1.34; 1.07-1.69) per 10 ppb increase. No dose-response trends were observed, and no clear relationships were found for specific histological cancer subtypes. There was the suggestion of increased risk among those living within 100 m of highways, but not among those living near major roads.

CONCLUSIONS

Lung cancer incidence in this Canadian study was increased most strongly with NO2 and PM2.5 exposure. Further investigation is needed into possible effects of O3 on development of lung cancer.

Spatial autocorrelation of cancer incidence in Saudi Arabia

Little is known about the geographic distribution of common cancers in Saudi Arabia. We explored the spatial incidence patterns of common cancers in Saudi Arabia using spatial autocorrelation analyses, employing the global Moran's I and Anselin's local Moran's I statistics to detect nonrandom incidence patterns. Global ordinary least squares (OLS) regression and local geographically-weighted regression (GWR) were applied to examine the spatial correlation of cancer incidences at the city level. Population-based records of cancers diagnosed between 1998 and 2004 were used. Male lung cancer and female breast cancer exhibited positive statistically significant global Moran's I index values, indicating a tendency toward clustering. The Anselin's local Moran's I analyses revealed small significant clusters of lung cancer, prostate cancer and Hodgkin's disease among males in the Eastern region and significant clusters of thyroid cancers in females in the Eastern and Riyadh regions. Additionally, both regression methods found significant associations among various cancers. For example, OLS and GWR revealed significant spatial associations among NHL, leukemia and Hodgkin's disease (r² = 0.49-0.67 using OLS and r² = 0.52-0.68 using GWR) and between breast and prostate cancer (r² = 0.53 OLS and 0.57 GWR) in Saudi Arabian cities. These findings may help to generate etiologic hypotheses of cancer causation and identify spatial anomalies in cancer incidence in Saudi Arabia. Our findings should stimulate further research on the possible causes underlying these clusters and associations.

NO(2) and cancer incidence in Saudi Arabia

Air pollution exposure has been shown to be associated with an increased risk of specific cancers. This study investigated whether the number and incidence of the most common cancers in Saudi Arabia were associated with urban air pollution exposure, specifically NO2. Overall, high model goodness of fit (GOF) was observed in the Eastern, Riyadh and Makkah regions. The significant coefficients of determination (r2) were higher at the regional level (r2 = 0.32-0.71), weaker at the governorate level (r2 = 0.03-0.43), and declined slightly at the city level (r2 = 0.17-0.33), suggesting that an increased aggregated spatial level increased the explained variability and the model GOF. However, the low GOF at the lowest spatial level suggests that additional variation remains unexplained. At different spatial levels, associations between NO2 concentration and the most common cancers were marginally improved in geographically weighted regression (GWR) analysis, which explained both global and local heterogeneity and variations in cancer incidence. High coefficients of determination were observed between NO2 concentration and lung and breast cancer incidences, followed by prostate, bladder, cervical and ovarian cancers, confirming results from other studies. These results could be improved using individual explanatory variables such as environmental, demographic, behavioral, socio-economic, and genetic risk factors.

The role of in vitro gene expression profiling in particulate matter health research

Exposure to particulate matter (PM) is consistently associated with increased morbidity and mortality rate. The mechanisms for these adverse health effects have been vigorously investigated for many years, but remain uncertain, in part due to the complex interactions between host and exposure. Over the past decade, the use of global gene expression profiling has increased to investigate molecular changes in an attempt to gain more insight into the complex mechanisms that underlie the adverse health effects induced by PM. These experiments have been performed mostly in cell cultures, in part due to the easy availability and maneuverability of different cell types. Whether or not the results obtained from these in vitro experiments are relevant to human exposure is unclear. In this study, cell culture studies were reviewed that used microarray technology to measure global gene expression in response to PM and the findings discussed in the context of global gene expression results obtained from animal and human exposure studies. Ten in vitro studies were identified from PubMed that reported global gene expression results in response to PM exposure. Despite difference in cell types, microarray platforms, incubation time, and PM sources and doses, these experiments showed commonality in the expression of genes and pathways, especially xenobiotic metabolism, oxidative stress, and inflammation. These gene expression profiles were consistent with results from animal and human controlled exposure experiments. The in vitro experiments also uncovered novel biological mechanisms that may be important in PM-induced health effects reported in epidemiological studies. Data indicate that in vitro microarray experiments complement animal and human exposure studies and allow the PM-associated health research to focus on the "toxic" components in PM and novel mechanisms, and may enhance risk assessment beyond the current mass-based standards.

Cancer hospitalizations in rural-urban areas in relation to carcinogenic discharges from Toxics Release Inventory facilities

This paper examines whether carcinogenic pollutants discharged from US Toxics Release Inventory (TRI) facilities are related to cancer hospitalization rates among the general population in rural and urban areas. We analyzed cancer hospitalizations (N = 440,061) across 20 states to find age- and sex-adjusted population cancer hospitalization rates. Multiple regression models were used to determine whether cancer hospitalization rates at the county level (N = 1102 counties) were associated with higher levels of carcinogenic discharges from TRI facilities, controlling for other risks. Significantly higher hospitalization rates were found in relation to higher TRI discharges for several cancer types that varied from urban to rural setting. Carcinogenic discharges from TRI facilities were associated with excess inpatient cancer treatment costs of $902.8 million in 2009. Future research may strive to move beyond ecological designs to examine cancer risks from TRI releases to better our understanding of cancer etiology and to establish appropriate environmental safeguards as indicated by the evidence.

Spatiotemporal air pollution exposure assessment for a Canadian population-based lung cancer case-control study

BACKGROUND

Few epidemiological studies of air pollution have used residential histories to develop long-term retrospective exposure estimates for multiple ambient air pollutants and vehicle and industrial emissions. We present such an exposure assessment for a Canadian population-based lung cancer case-control study of 8353 individuals using self-reported residential histories from 1975 to 1994. We also examine the implications of disregarding and/or improperly accounting for residential mobility in long-term exposure assessments.

METHODS

National spatial surfaces of ambient air pollution were compiled from recent satellite-based estimates (for PM2.5 and NO2) and a chemical transport model (for O3). The surfaces were adjusted with historical annual air pollution monitoring data, using either spatiotemporal interpolation or linear regression. Model evaluation was conducted using an independent ten percent subset of monitoring data per year. Proximity to major roads, incorporating a temporal weighting factor based on Canadian mobile-source emission estimates, was used to estimate exposure to vehicle emissions. A comprehensive inventory of geocoded industries was used to estimate proximity to major and minor industrial emissions.

RESULTS

Calibration of the national PM2.5 surface using annual spatiotemporal interpolation predicted historical PM2.5 measurement data best (R2 = 0.51), while linear regression incorporating the national surfaces, a time-trend and population density best predicted historical concentrations of NO2 (R2 = 0.38) and O3 (R2 = 0.56). Applying the models to study participants residential histories between 1975 and 1994 resulted in mean PM2.5, NO2 and O3 exposures of 11.3 μg/m3 (SD = 2.6), 17.7 ppb (4.1), and 26.4 ppb (3.4) respectively. On average, individuals lived within 300 m of a highway for 2.9 years (15% of exposure-years) and within 3 km of a major industrial emitter for 6.4 years (32% of exposure-years). Approximately 50% of individuals were classified into a different PM2.5, NO2 and O3 exposure quintile when using study entry postal codes and spatial pollution surfaces, in comparison to exposures derived from residential histories and spatiotemporal air pollution models. Recall bias was also present for self-reported residential histories prior to 1975, with cases recalling older residences more often than controls.

CONCLUSIONS

We demonstrate a flexible exposure assessment approach for estimating historical air pollution concentrations over large geographical areas and time-periods. In addition, we highlight the importance of including residential histories in long-term exposure assessments. For submission to: Environmental Health.

Cell type specificity of female lung cancer associated with sulfur dioxide from air pollutants in Taiwan: an ecological study

Background

Many studies have examined the association between air pollutants (including sulfur dioxide [SO₂], carbon monoxide [CO], nitrogen dioxide [NO₂], nitric oxide [NO], ozone [O₃], and particulate matter < 10 μm [PM₁₀]) and lung cancer. However, data from previous studies on pathological cell types were limited, especially for SO₂ exposure. We aimed to explore the association between SO₂ exposure from outdoor air pollutants and female lung cancer incidence by cell type specificity.

Methods

We conducted an ecological study and calculated annual average concentration of 6 air pollutants (SO₂, CO, NO₂, NO, O₃, and PM₁₀) using data from Taiwan Environmental Protection Administration air quality monitoring stations. The Poisson regression models were used to evaluate the association between SO₂ and age-standardized incidence rate of female lung cancer by two major pathological types (adenocarcinoma [AC] and squamous cell carcinoma [SCC]). In order to understand whether there is a dose-response relationship between SO₂ and two major pathological types, we analyzed 4 levels of exposure based on quartiles of concentration of SO₂.

Results

The Poisson regression results showed that with the first quartile of SO₂ concentration as the baseline, the relative risks for AC/SCC type cancer among females were 1.20 (95% confidence interval [CI], 1.04-1.37)/1.39 (95% CI, 0.96-2.01) for the second, 1.22 (95% CI, 1.04-1.43)/1.58 (95% CI, 1.06-2.37) for the third, and 1.27 (95% CI, 1.06-1.52)/1.80 (95% CI, 1.15-2.84) for the fourth quartile of SO₂ concentration. The tests for trend were statistically significant for both AC and SCC at P = 0.0272 and 0.0145, respectively.

Conclusion

The current study suggests that SO₂ exposure as an air pollutant may increase female lung cancer incidence and the associations with female lung cancer is much stronger for SCC than for AC. The findings of this study warrant further investigation on the role of SO₂ in the etiology of SCC.

An ecologic analysis of county-level PM2.5 concentrations and lung cancer incidence and mortality

Few studies have explored the relationship between PM2.5 and lung cancer incidence. Although results are mixed, some studies have demonstrated a positive relationship between PM2.5 and lung cancer mortality. Using an ecologic study design, we examined the county-level associations between PM2.5 concentrations (2002-2005) and lung cancer incidence and mortality in North Carolina (2002-2006). Positive trends were observed between PM2.5 concentrations and lung cancer incidence and mortality; however, the R2 for both were <0.10. The slopes for the relationship between PM2.5 and lung cancer incidence and mortality were 1.26 (95% CI 0.31, 2.21, p-value 0.01) and 0.73 (95% CI 0.09, 1.36, p-value 0.03) per 1 μg/m3 PM2.5, respectively. These associations were slightly strengthened with the inclusion of variables representing socioeconomic status and smoking. Although variability is high, thus reflecting the importance of tobacco smoking and other etiologic agents that influence lung cancer incidence and mortality besides PM2.5, a positive trend is observed between PM2.5 and lung cancer incidence and mortality. This suggests the possibility of an association between PM2.5 concentrations and lung cancer incidence and mortality.

Examining the joint effect of multiple risk factors using exposure risk profiles: lung cancer in nonsmokers

BACKGROUND

Profile regression is a Bayesian statistical approach designed for investigating the joint effect of multiple risk factors. It reduces dimensionality by using as its main unit of inference the exposure profiles of the subjects that is, the sequence of covariate values that correspond to each subject.

OBJECTIVES

We applied profile regression to a case-control study of lung cancer in nonsmokers, nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, to estimate the combined effect of environmental carcinogens and to explore possible gene-environment interactions.

METHODS

We tailored and extended the profile regression approach to the analysis of case-control studies, allowing for the analysis of ordinal data and the computation of posterior odds ratios. We compared and contrasted our results with those obtained using standard logistic regression and classification tree methods, including multifactor dimensionality reduction.

RESULTS

Profile regression strengthened previous observations in other study populations on the role of air pollutants, particularly particulate matter ≤ 10 μm in aerodynamic diameter (PM10), in lung cancer for nonsmokers. Covariates including living on a main road, exposure to PM10 and nitrogen dioxide, and carrying out manual work characterized high-risk subject profiles. Such combinations of risk factors were consistent with a priori expectations. In contrast, other methods gave less interpretable results.

CONCLUSIONS

We conclude that profile regression is a powerful tool for identifying risk profiles that express the joint effect of etiologically relevant variables in multifactorial diseases.

Pulmonary nodules in workers exposed to urban stressor

By multilayer spiral low-dose computed tomography (LD-CT) of the chest this study assesses the early detection of lung lesions on a sample of 100 traffic policemen of a big Italian city professionally exposed to urban pollutants and 100 controls non-occupationally exposed to urban pollutants matched by sex, age, length of service and cigarette smoking habit. Exposure to urban pollutants in traffic policemen was characterized using the annual average concentrations of PM(10), NO2 and benzene in the period 1998-2008 measured by fixed monitoring stations located in different areas of the city. A significant and increasing number of suspicious lung nodules with diameters between 5 and 10 mm was observed: in traffic policemen (including smokers and non-smokers) vs. controls (including smokers and non-smokers); in total smokers (including traffic policemen and controls) vs. total non-smokers (traffic policemen and controls); in smoker traffic policemen vs. smoker controls and vs. non-smoker traffic policemen; in non-smoker traffic policemen vs. non-smoker controls. The RR of finding cases with at least one lung nodule with diameters between 5 and 10mm in traffic policemen (including smokers and non-smokers) compared to controls (including smokers and non-smokers) is 1.94 (CI 1.13-3.31); in total smokers vs. non-smokers the RR is 1.96 (CI 1.20-3.19). The comparison between the interaction exposure and smoking shows an increase in smoker traffic policemen than in smoker controls (RR=2.14; CI 1.02-4.52). The RR for smoker traffic policemen was higher than in non-smoker traffic policemen (RR=2.09; CI 1.19-3.66). The results of our study show that: (1) while smoker workers have a higher risk for developing solid suspicious lung nodules, the simple routinely exposure to urban pollutants is unable to produce the same kind of increased risk; (2) the interaction of smoking and exposure to urban pollutants greatly increases the risk for the development of solid suspicious lung nodules. In conclusion, the use of chest LD-CT in workers at risk helps identify suspicious solid lung nodules at early stage.

Is there a future for biomonitoring of elemental air pollution? A review focused on a larger-scaled health-related (epidemiological) context

The present paper focuses on biomonitoring of elemental atmospheric pollution, which is reviewed in terms of larger-scaled biomonitoring surveys in an epidemiological context. Based on the literature information, today's availability of solar-powered small air filter samplers and fibrous ion exchange materials is regarded as adequate or an even better alternative for biomonitor transplant materials used in small-scaled set-ups, but biomonitors remain valuable in larger-scaled set-ups and in unforeseen releases and accidental situations. In the latter case, in-situ biomonitoring is seen as the only option for a retrospective study: biomoniors are there before one even knows that they are needed. For biomonitoring, nuclear analytical techniques are discussed as key techniques, especially because of the necessary multi-element assessments in both source recognition and single-element interpretation. To live up to the demands in an epidemiological context, larger-scaled in-situ biomonitoring asks for large numbers of samples, and consequently, for large total sample masses, this all to ensure representation of both local situations and survey area characteristics. Possibly, this point should direct studies into new "easy-to-sample" biomonitor organisms, of which high masses and numbers may be obtained in field work, rather than continue with biomonitors such as lichens. This also means that both sample handling and processing are of key importance in these studies. To avoid problems in comparability of analytical general procedures in milling, homogenization and digestion of samples of large masses, the paper proposes to involve only few but high-quality laboratories in the total element assessment routines. In this respect, facilities that can handle large sample masses in the assessment of element concentrations are to be preferred. This all highlights the involvement of large-sample-volume nuclear facilities, which, however, should be upgraded and automated in their operation to ensure the necessary sample throughput in larger-scaled biomonitoring.

Dosimetry and toxicology of inhaled ultrafine particles

Both epidemiological and toxicological studies indicate that inhalation and subsequent deposition of airborne particles into the lungs have adverse health effects. Recently, the ultrafine particle (UfP) fraction (diameter < 100 nm) has received particular attention, as their small size may lead to more toxic properties. In this study we summarize the current knowledge on the dosimetry of inhaled particles (including UfPs) with a focus on recent data on translocation of UfPs into secondary target organs (such as brain and heart) suggesting that the lifetime dose of ambient UfPs in secondary target organs is about 10(11) particles. Furthermore, we highlight the main pathways of particle induced toxicity and the reasons for the potentially higher toxicity of UfPs. Finally, we discuss recent evidence indicating that (BET) surface area is the single most relevant dose metric for the toxicity of UfPs, which has important implications for regulatory measures on the toxicity of ambient and engineered particles.

A critical assessment of geographic clusters of breast and lung cancer incidences among residents living near the Tittabawassee and Saginaw Rivers, Michigan, USA

OBJECTIVES

To assess previously determined geographic clusters of breast and lung cancer incidences among residents living near the Tittabawassee and Saginaw Rivers, Michigan, using a new set of environmental factors.

MATERIALS AND METHODS

Breast and lung cancer data were acquired from the Michigan Department of Community Health, along with point source pollution data from the U.S. Environmental Protection Agency. The datasets were used to determine whether there is a spatial association between disease risk and environmental contamination. GIS and spatial techniques were combined with statistical analysis to investigate local risk of breast and lung cancer.

RESULTS AND CONCLUSION

The study suggests that neighborhoods in close proximity to the river were associated with a high risk of breast cancer, while increased risk of lung cancer was detected among neighborhoods in close proximity to point source pollution and major highways. Statistically significant (P Collapse

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MESH Headings

• Adolescent
• Adult
• Age Distribution
• Breast Neoplasms/chemically induced
• Breast Neoplasms/epidemiology
• Cluster Analysis
• Discriminant Analysis
• Environmental Exposure/adverse effects
• Environmental Pollution/adverse effects
• Female
• Geographic Information Systems
• Humans
• Incidence
• Industry
• Lung Neoplasms/chemically induced
• Lung Neoplasms/epidemiology
• Male
• Michigan/epidemiology
• Middle Aged
• Odds Ratio
• Residence Characteristics
• Retrospective Studies
• Risk Factors
• Rivers
• Soil Pollutants/poisoning
• Water Pollutants, Chemical/poisoning
• Young Adult

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Affiliation(s)

Olga A. Guajardo Advanced Geospatial Analysis Lab, Department of Geography and Environmental Resources, Southern Illinois University, 1000 Faner Drive, MC 4514, Carbondale, IL 62901-4514, USA
Tonny J. Oyana Advanced Geospatial Analysis Lab, Department of Geography and Environmental Resources, Southern Illinois University, 1000 Faner Drive, MC 4514, Carbondale, IL 62901-4514, USA

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Toxicity and carcinogenicity of ozone in combination with 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone and dibutyl phthalate in B6C3F1 mice for 16 and 32 weeks

OBJECTIVE

To evaluate the toxic and carcinogenic potential of ozone alone or in combination with 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and/or dibutyl phthalate (DBP).

METHODS

Male and female B6C3F1 mice were exposed, through inhalation, intravenous administration and diet, to 0.5 ppm of ozone, 1.0 mg/kg of NNK and 5000 ppm of DBP, individually and in combination for 16 and 32 weeks.

RESULTS

No treatment-related death was seen, but significant differences in body and organ weights between control and treated mice were observed during the study. No incidence of lung tumor incidence was recorded in mice exposed to either ozone alone or combined treatment. Oviductal carcinomas were observed in female mice exposed to ozone or DBP alone for 16 weeks and ozone in combination with NNK and DBP for 32 weeks.

CONCLUSION

Although ozone alone and in conjunction with NNK and/or DBP does not induce lung cancer under our experimental conditions, they induce oviductal carcinomas in B6C3F1 mice.

Airborne particulate matter and human health: toxicological assessment and importance of size and composition of particles for oxidative damage and carcinogenic mechanisms

Air pollution has been considered a hazard to human health. In the past decades, many studies highlighted the role of ambient airborne particulate matter (PM) as an important environmental pollutant for many different cardiopulmonary diseases and lung cancer. Numerous epidemiological studies in the past 30 years found a strong exposure-response relationship between PM for short-term effects (premature mortality, hospital admissions) and long-term or cumulative health effects (morbidity, lung cancer, cardiovascular and cardiopulmonary diseases, etc). Current research on airborne particle-induced health effects investigates the critical characteristics of particulate matter that determine their biological effects. Several independent groups of investigators have shown that the size of the airborne particles and their surface area determine the potential to elicit inflammatory injury, oxidative damage, and other biological effects. These effects are stronger for fine and ultrafine particles because they can penetrate deeper into the airways of the respiratory tract and can reach the alveoli in which 50% are retained in the lung parenchyma. Composition of the PM varies greatly and depends on many factors. The major components of PM are transition metals, ions (sulfate, nitrate), organic compound, quinoid stable radicals of carbonaceous material, minerals, reactive gases, and materials of biologic origin. Results from toxicological research have shown that PM have several mechanisms of adverse cellular effects, such as cytotoxicity through oxidative stress mechanisms, oxygen-free radical-generating activity, DNA oxidative damage, mutagenicity, and stimulation of proinflammatory factors. In this review, the results of the most recent epidemiological and toxicological studies are summarized. In general, the evaluation of most of these studies shows that the smaller the size of PM the higher the toxicity through mechanisms of oxidative stress and inflammation. Some studies showed that the extractable organic compounds (a variety of chemicals with mutagenic and cytotoxic properties) contribute to various mechanisms of cytotoxicity; in addition, the water-soluble faction (mainly transition metals with redox potential) play an important role in the initiation of oxidative DNA damage and membrane lipid peroxidation. Associations between chemical compositions and particle toxicity tend to be stronger for the fine and ultrafine PM size fractions. Vehicular exhaust particles are found to be most responsible for small-sized airborne PM air pollution in urban areas. With these aspects in mind, future research should aim at establishing a cleared picture of the cytotoxic and carcinogenic mechanisms of PM in the lungs, as well as mechanisms of formation during internal engine combustion processes and other sources of airborne fine particles of air pollution.

Lung cancer mortality in towns near paper, pulp and board industries in Spain: a point source pollution study

BACKGROUND

This study sought to ascertain whether there might be excess lung cancer mortality among the population residing in the vicinity of Spanish paper and board industries which report their emissions to the European Pollutant Emission Register (EPER).

METHODS

This was an ecological study that modelled the Standardised Mortality Ratio (SMR) for lung cancer in 8073 Spanish towns over the period 1994-2003. Population exposure to industrial pollution was estimated on the basis of distance from town of residence to pollution source. An exploratory, near-versus-far analysis was conducted, using mixed Poisson regression models and an analysis of the effect of municipal proximity within a 50-kilometre radius of each of the 18 installations.

RESULTS

Results varied for the different facilities. In two instances there was an increasing mortality gradient with proximity to the installation, though this was exclusively observed among men.

CONCLUSION

The study of cancer mortality in areas surrounding pollutant foci is a useful tool for environmental surveillance, and serves to highlight areas of interest susceptible to being investigated by ad hoc studies. Despite present limitations, recognition is therefore due to the advance represented by publication of the EPER and the study of pollutant foci.

Assessment of population exposure to particulate matter pollution in Chongqing, China

To determine the population exposure to PM(10) in Chongqing, China, we developed an indirect model by combining information on the time activity patterns of various demographic subgroups with estimates of the PM(10) concentrations in different microenvironments (MEs). The spatial and temporal variations of the exposure to PM(10) were illustrated in a geographical information system (GIS). The population weighted exposure (PWE) for the entire population was 229, 155 and 211 microg/m(3), respectively, in winter, summer and as the annual average. Indoor PM(10) level at home was the largest contributor to the PWE, especially for the rural areas where high pollution levels were found due to solid fuels burning. Elder people had higher PM(10) exposure than adults and youth, due to more time spent in indoor MEs. The highest health risk due to particulate was found in the city zone and northeast regions, suggesting that pollution abatement should be prioritized in these areas.

Near-highway pollutants in motor vehicle exhaust: a review of epidemiologic evidence of cardiac and pulmonary health risks

There is growing evidence of a distinct set of freshly-emitted air pollutants downwind from major highways, motorways, and freeways that include elevated levels of ultrafine particulates (UFP), black carbon (BC), oxides of nitrogen (NOx), and carbon monoxide (CO). People living or otherwise spending substantial time within about 200 m of highways are exposed to these pollutants more so than persons living at a greater distance, even compared to living on busy urban streets. Evidence of the health hazards of these pollutants arises from studies that assess proximity to highways, actual exposure to the pollutants, or both. Taken as a whole, the health studies show elevated risk for development of asthma and reduced lung function in children who live near major highways. Studies of particulate matter (PM) that show associations with cardiac and pulmonary mortality also appear to indicate increasing risk as smaller geographic areas are studied, suggesting localized sources that likely include major highways. Although less work has tested the association between lung cancer and highways, the existing studies suggest an association as well. While the evidence is substantial for a link between near-highway exposures and adverse health outcomes, considerable work remains to understand the exact nature and magnitude of the risks.