Exposure to Traffic Emissions and Fine Particulate Matter and Computed Tomography Measures of the Lung and Airways

Imaging Climate-Related Environmental Exposures: Impact and Opportunity

Climate change is the most important challenge of this century. Global surface temperature is continuously rising to new record highs, adversely affecting the health of the planet and humans. The purpose of this article is to review the impact of climate related environmental exposures on human health, healthcare delivery, and medical imaging and explore the potential to leverage medical imaging as a non-invasive tool to advance our understanding of climate related health effects. Radiology departments and healthcare systems must focus on building resilience to the effects of climate change while ensuring that the delivery of care is environmentally sustainable. Further research is needed to refine our understanding of the effects of climate change on human health and to forecast the expected changes in the demand for healthcare and radiology services.

Association of Insulin Resistance With Radiographic Lung Abnormalities and Incident Lung Disease: The Framingham Offspring Study

OBJECTIVE

Insulin resistance (IR) may be a risk factor for lung disease, but objective evidence is limited. We sought to define the relationship of longitudinal IR with radiographic imaging outcomes and examiner-identified incident lung disease in the Framingham Offspring Study.

RESEARCH DESIGN AND METHODS

Participants without baseline lung disease underwent repeated measurements of fasting insulin and glucose levels over an average period of 13.6 years, from which time-weighted average HOMA-IR was calculated. Each participant then underwent a cardiac gated whole-lung computed tomography scan, which was analyzed for the presence of emphysema, interstitial lung abnormalities (ILAs), and quantitative airway features. Incident lung disease was determined by a study examiner. The relationship of HOMA-IR to these outcomes was estimated in models adjusted for demographics, BMI, and lifetime smoking.

RESULTS

A total of 875 participants with longitudinal IR data and outcomes were identified. Their mean age was 51.5 years, and BMI was 26.7 kg/m2. HOMA-IR was temporally unstable, with a within-person SD approximately two-thirds of the between-person SD. In adjusted models, a 1 SD increase in log(HOMA-IR) z score was associated with higher odds of qualitative emphysema (odds ratio [OR] 1.33; 95% CI 1.04-1.70), ILAs (OR 1.35; 95% CI 1.05-1.74), and modest increases in airway wall thickness and wall area percentage. These radiographic findings were corroborated by a positive association of HOMA-IR with incident lung disease.

CONCLUSIONS

IR is associated with radiographic lung abnormalities and incident lung disease. Deeper phenotyping is necessary to define mechanisms of IR-associated lung injury.

Airway Mucus Plugs in Community-Living Adults: A Study Protocol

Introduction

Mucus pathology plays a critical role in airway diseases like Chronic Bronchitis (CB) and Chronic Obstructive Pulmonary Disease (COPD). Up to 32% of community-living persons report clinical manifestations of mucus pathology (e.g., cough and sputum production). However, airway mucus pathology has not been systematically studied in community-living individuals. In this study, we will use an objective, reproducible assessment of mucus pathology on chest Computed Tomography (CT) scans from community-living individuals participating in the Coronary Artery Risk Development in Young Adults (CARDIA) and Framingham Heart Study (FHS) cohorts.

Methods and analysis

We will determine the clinical relevance of CT-based mucus plugs and modifiable and genetic risk and protective factors associated with this process. We will evaluate the associations of mucus plugs with lung function, respiratory symptoms, and chronic bronchitis and examine whether 5-yr. persistent CT-based mucus plugs are associated with the decline in FEV1 and future COPD. Also, we will assess whether modifiable factors, including air pollution and marijuana smoking are associated with increased odds of CT-based mucus plugs and whether cardiorespiratory fitness is related in an opposing manner. Finally, we will determine genetic resilience/susceptibility to mucus pathology. We will use CT data from the FHS and CARDIA cohorts and genome-wide sequencing data from the TOPMed initiative to identify common and rare variants associated with CT-based mucus plugging.

Ethics and dissemination

The Mass General Brigham Institutional Review Board approved the study. Findings will be disseminated through peer-reviewed journals and at professional conferences.

Conclusion

Determine whether the presence of CT-based mucus plugs is associated with lung health impairment, including reduced FEV1, more respiratory symptoms, and asthma. Identify modifiable risk and protective factors, such as pollution, exercise, smoking, and fitness that are associated with mucus plugs.

Airway Mucus Plugs in Community-Living Adults: A Study Protocol

Introduction

Mucus pathology plays a critical role in airway diseases like chronic bronchitis (CB) and chronic obstructive pulmonary disease (COPD). Up to 32% of community-living persons report clinical manifestations of mucus pathology (e.g., cough and sputum production). However, airway mucus pathology has not been systematically studied in community-living individuals. In this study, we will use an objective, reproducible assessment of mucus pathology on chest computed tomography (CT) scans from community-living individuals participating in the Coronary Artery Risk Development in Young Adults (CARDIA) and Framingham Heart Study (FHS) cohorts.

Methods and analysis

We will determine the clinical relevance of CT-based mucus plugs and modifiable and genetic risk and protective factors associated with this process. We will evaluate the associations of mucus plugs with lung function, respiratory symptoms, and chronic bronchitis and examine whether 5-yr. persistent CT-based mucus plugs are associated with the decline in FEV1 and future COPD. Also, we will assess whether modifiable factors, including air pollution and marijuana smoking are associated with increased odds of CT-based mucus plugs and whether cardiorespiratory fitness is related in an opposing manner. Finally, we will determine genetic resilience/susceptibility to mucus pathology. We will use CT data from the FHS and CARDIA cohorts and genome-wide sequencing data from the TOPMed initiative to identify common and rare variants associated with CT-based mucus plugging.

Ethics and Dissemination

The Mass General Brigham Institutional Review Board approved the study. Findings will be disseminated through peer-reviewed journals and at professional conferences.

Characteristics and health risk assessment of heavy metal pollution in atmospheric particulate matter in different regions of the Yellow River Delta in China

To understand the characteristics, temporal and spatial variation, and health risks of atmospheric heavy metal pollution in different areas of the YRD (Yellow River Delta), atmospheric particles samples were collected in the YRD in China during 2016-2017. A total of 10 monitoring points were chosen in different areas (industrial parks, main urban areas, and rural areas) in the YRD, heavy metals were monitored using atomic fluorescence spectrometry and graphite furnace atomic absorption spectrometry. The results showed that TSP (total suspended particulate), PM₁₀ (particulate matter with an aerodynamic diameter less than 10 μm), and PM_2.5 (particulate matter with an aerodynamic diameter less than 2.5 μm) contents were higher in the Kenli EDZ (economic development zone) and Kenli urban areas than those in other points. The concentration range of heavy metals in atmospheric samples at 10 points was different, with a difference of five orders of magnitude, of which the content of copper (Cu) was the highest, with the highest concentration of 4.375 μg/m³, and the content of particulate mercury (Hg) was the lowest, with the minimum concentration of 0.00001 μg/m³. Among the nine heavy metals, the contents of cadmium (Cd), lead (Pb), and Hg were higher in winter than in summer, and chromium (Cr), nickel (Ni), Cu, and manganese (Mn) were higher in summer than in winter. In addition to Hg, the contents of the other eight heavy metals in particulate matter showed a trend that urban areas and EDZs had higher concentrations than cities and towns and nature reserves, which can be attributed to industrial activities and coal-fired fuel emissions. Health risk assessment was carried out for adults and children, respectively, and the results showed that carcinogens have no obvious carcinogenic risk, but As and Cr have major potential carcinogenic risk. Among the noncarcinogenic substances, Mn has the greatest noncarcinogenic risk, and urban areas and economic development zones have the greatest risk. This study investigated the characteristics and health risk assessment of atmospheric heavy metal pollution in different areas in the YRD to supplement the research contents of atmospheric particulate heavy metals in the YRD in domestics and overseas. It is also critical to study the pollution and migration of heavy metals in China.

Long-term personal PM2.5 exposure and lung function alternation: A longitudinal study in Wuhan urban adults

BACKGROUND

The effect of long-term PM_2.5 exposure on lung function has not been well established.

OBJECTIVES

To investigate the effects of long-term personal PM_2.5 exposure on lung function decline, obstructive, and restrictive ventilatory disorders.

METHOD

Personal PM_2.5 concentrations were evaluated using an estimation model. Lung function parameters including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁) and peak expiratory flow (PEF) were measured in 3053 Wuhan participants from the Wuhan-Zhuhai cohort and were repeated every 3 years. Participants were classified into persistently high exposure group, persistently low exposure group and inconsistent exposure group according to the median of PM_2.5 concentration of each visit. Mixed linear models with subject-specific random intercept were used to assess the association of 3-year change of lung function with personal PM_2.5 exposure, and generalized linear models were used to assess the association of 6-year change of lung function with personal PM_2.5 exposure. Cox regression models were applied to assess the associations of PM_2.5 with obstructive and restrictive ventilatory disorders.

RESULTS

The medians of personal PM_2.5 concentrations at baseline and two follow-ups were 153.18, 209.57 and 83.78 μg/m³, respectively. Compared with participants in the persistently low exposure group, participants in the persistently high exposure group showed a 2.99 % (95 % CI: 0.91, 5.08), a 380.15 mL/s (95 % CI: 32.82, 727.48) and a 5.98 % (95 % CI: 0.84, 11.11) additional decline in FEV₁/FVC, PEF and PEFpred after 6 years, respectively. Stratified analyses showed that age, gender, body mass index, smoking status and drinking status had no significant modification effect on the associations. The associations of PM_2.5 exposure with obstructive and restrictive ventilatory disorders were not significant, except for a positive association between persistently high PM_2.5 exposure and restrictive ventilatory disorder among ever drinkers.

CONCLUSION

Long-term high PM_2.5 exposure was associated with FEV₁/FVC, PEF and PEFpred declines.

The relationship between traffic-related air pollution exposures and allostatic load score among youth with type 1 diabetes in the SEARCH cohort

OBJECTIVE

We investigated the effects of chronic exposures to particulate and traffic-related air pollution on allostatic load (AL) score, a marker of cumulative biological risk, among youth with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Participants were drawn from five clinical sites of the SEARCH for Diabetes in Youth (SEARCH) study (n = 2338). Baseline questionnaires, anthropometric measures, and a fasting blood test were taken at a clinic visit between 2001 and 2005. AL was operationalized using 10 biomarkers reflecting cardiovascular, metabolic, and inflammatory risk. Annual residential exposures to PM2.5 and proximity to heavily-trafficked major roadways were estimated for each participant. Poisson regression models adjusted for sociodemographic and lifestyle factors were conducted for each exposure.

RESULTS

No significant associations were observed between exposures to PM2.5 or proximity to traffic and AL score, however analyses were suggestive of effect modification by race for residential distance to heavily-trafficked major roadways (p = 0.02). In stratified analyses, residing <100, 100-<200 and 200-<400 m compared to 400 m or more from heavily-trafficked major roadways was associated with 11%, 26% and 14% increases in AL score, respectively (95% CIs: -4, 29; 9, 45; -1, 30) for non-white participants compared to 6%, -2%, and -2% changes (95% CIs: -2, 15; -10, 7; -8, 6) for white participants.

CONCLUSIONS

Among this population of youth with type 1 diabetes, we did not observe consistent relationships between chronic exposures to particulate and traffic-related air pollution and changes in AL score, however associations for traffic-related pollution exposures may differ by race/ethnicity and warrant further examination.

Ambient air pollution exposure and radiographic pulmonary vascular volumes

Supplemental Digital Content is available in the text.

Exposure to higher levels of ambient air pollution is a known risk factor for cardiovascular disease but long-term effects of pollution exposure on the pulmonary vessels are unknown.

Vascular Pruning on CT and Interstitial Lung Abnormalities in the Framingham Heart Study

BACKGROUND

Pulmonary vascular disease is associated with poor outcomes in individuals affected by interstitial lung disease. The pulmonary vessels can be quantified with noninvasive imaging, but whether radiographic indicators of vasculopathy are associated with early interstitial changes is not known.

RESEARCH QUESTION

Are pulmonary vascular volumes, quantified from CT scans, associated with interstitial lung abnormalities (ILA) in a community-based sample with a low burden of lung disease?

STUDY DESIGN AND METHODS

In 2,386 participants of the Framingham Heart Study, we used CT imaging to calculate pulmonary vascular volumes, including the small vessel fraction (a surrogate of vascular pruning). We constructed multivariable logistic regression models to investigate associations of vascular volumes with ILA, progression of ILA, and restrictive pattern on spirometry. In secondary analyses, we additionally adjusted for diffusing capacity and emphysema, and performed a sensitivity analysis restricted to participants with normal FVC and diffusing capacity.

RESULTS

In adjusted models, we found that lower pulmonary vascular volumes on CT were associated with greater odds of ILA, antecedent ILA progression, and restrictive pattern on spirometry. For example, each SD lower small vessel fraction was associated with 1.81-fold greater odds of ILA (95% CI, 1.41-2.31; P < .0001), and 1.63-fold greater odds of restriction on spirometry (95% CI, 1.18-2.24; P = .003). Similar patterns were seen after adjustment for diffusing capacity for carbon monoxide, emphysema, and among participants with normal lung function.

INTERPRETATION

In this cohort of community-dwelling adults not selected on the basis of lung disease, more severe vascular pruning on CT was associated with greater odds of ILA, ILA progression, and restrictive pattern on spirometry. Pruning on CT may be an indicator of early pulmonary vasculopathy associated with interstitial lung disease.

Long-term exposure to PM10 and NO2 in relation to lung function and imaging phenotypes in a COPD cohort

BACKGROUND

Ambient air pollution can contribute to the development and exacerbation of COPD. However, the influence of air pollution on objective COPD phenotypes, especially from imaging, is not well studied. We investigated the influence of long-term exposure to air pollution on lung function and quantitative imaging measurements in a Korean cohort of participants with and without COPD diagnosis.

METHODS

Study participants (N = 457 including 296 COPD cases) were obtained from the COPD in Dusty Areas (CODA) cohort. Annual average concentrations of particulate matter less than or equal to 10 μm in diameter (PM10) and nitrogen dioxide (NO2) were estimated at the participants' residential addresses using a spatial air pollution prediction model. All the participants underwent volumetric computerized tomography (CT) and spirometry measurements and completed survey questionnaires. We examined the associations of PM10 and NO2 with FVC, FEV1, emphysema index, and wall area percent, using linear regression models adjusting for age, gender, education, smoking, height, weight, and COPD medication.

RESULTS

The age of study participants averaged 71.7 years. An interquartile range difference in annual PM10 exposure of 4.4 μg/m3 was associated with 0.13 L lower FVC (95% confidence interval (CI), - 0.22- -0.05, p = 0.003). Emphysema index (mean = 6.36) was higher by 1.13 (95% CI, 0.25-2.02, p = 0.012) and wall area percent (mean = 68.8) was higher by 1.04 (95% CI, 0.27-1.80, p = 0.008). Associations with imaging phenotypes  were not observed with NO2.

CONCLUSIONS

Long-term exposure to PM10 correlated with both lung function and COPD-relevant imaging phenotypes in a Korean cohort.

The Framingham Heart Study: Populational CT-based phenotyping in the lungs and mediastinum

The Framingham Heart Study (FHS) is one of the largest and established longitudinal populational cohorts. CT cohorts of the FHS since 2002 provided a unique opportunity to assess non-cardiac thoracic imaging findings. This review deals with image-based phenotyping studies from recent major publications regarding interstitial lung abnormalities (ILAs), pulmonary cysts, emphysema, pulmonary nodules, pleural plaques, normal spectrum of the thymus, and anterior mediastinal masses, concluding with the discussion of future directions of FHS CT cohorts studies in the era of radiomics and artificial intelligence.

Cigarette Smoke Exposure and Radiographic Pulmonary Vascular Morphology in the Framingham Heart Study

Rationale: Cigarette smoke exposure is a risk factor for many lung diseases, and histologic studies suggest that tobacco-related vasoconstriction and vessel loss plays a role in the development of emphysema. However, it remains unclear how tobacco affects the pulmonary vasculature in general populations with a typical range of tobacco exposure, and whether these changes are detectable by radiographic methods. Objectives: To determine whether tobacco exposure in a generally healthy population manifests as lower pulmonary blood vessel volumes and vascular pruning on imaging. Methods: A total of 2,410 Framingham Heart Study participants with demographic data and smoking history underwent volumetric whole-lung computed tomography from 2008 to 2011. Automated algorithms calculated the total blood volume of all intrapulmonary vessels (TBV), smaller peripheral vessels (defined as cross-sectional area <5 mm² [BV5]), and the relative fraction of small vessels (BV5/TBV). Tobacco exposure was assessed as smoking status, cumulative pack-years, and second-hand exposure. We constructed multivariable linear regression models to evaluate associations of cigarette exposure and pulmonary blood vessel volume measures, adjusting for demographic covariates, including age, sex, height, weight, education, occupation, and median neighborhood income. Results: All metrics of tobacco exposure (including smoking status, pack-years, and second-hand exposure) were consistently associated with higher absolute pulmonary blood vessel volume, higher small vessel volume, and/or higher small vessel fraction. For example, ever-smokers had a 4.6 ml higher TBV (95% confidence interval [CI] = 2.9-6.3, P < 0.001), 2.1 ml higher BV5 (95% CI = 1.3-2.9, P < 0.001), and 0.28 percentage-point-higher BV5/TBV (95% CI = 0.03-0.52, P = 0.03) compared with never-smokers. These associations remained significant after adjustment for percent predicted forced expiratory volume in 1 second, cardiovascular comorbidities, and did not differ based on presence or absence of airflow obstruction. Conclusions: Using computed tomographic imaging, we found that cigarette exposure was associated with higher pulmonary blood vessel volumes, especially in the smaller peripheral vessels. Although, histologically, tobacco-related vasculopathy is characterized by vessel narrowing and loss, our results suggest that radiographic vascular pruning may not be a surrogate of these pathologic changes.

Effect of Nigella sativa and Foeniculum vulgare seeds extracts on male mice exposed to carbendazim

The increasing prevalence of environmental pollutants such as pesticides is a major global problem that affects living organisms. Exposure to environmental pollutants remains a major source of health risk throughout the world. The potential health benefits of various medicinal plants and natural products in relation to protect various diseases are currently receiving considerable attention. A current approach is to develop a new biological compound from natural products that inhibits pain. Ethnopharmacological surveys have been found to be one of the most reliable tools for the discovery of the natural and semi-synthetic drug. The present study was performed to investigate the hematological and biochemical changes induced by carbendazim (CBZ) and the potential protective effect of seeds extracts of Nigella sativa (NSSE) and Foeniculum vulgare (FVSE) against CBZ toxicity in male mice. Mice were distributed into 6 groups. Mice of group 1 were served as control. Group 2 was exposed to CBZ. Group 3 was supplemented with NSSE and exposed to CBZ. Group 4 was treated with FVSE and CBZ. Normal mice of group 5 and 6 were subjected to NSSE and FVSE respectively. Body weight gain was significantly decreased in mice of group 2. In mice of group 2, significant declines of RBC, HB, Hct, WBC, total protein, FSH, LH, testosterone, T4, T3, CAT and SOD were observed. Moreover, the levels of ALT, AST, ALP, total bilirubin, creatinine, BUN, uric acid, glucose, cholesterol, CK, LDH, MDA and GSH were significantly enhanced. Treatment with NSSE and FVSE showed attenuation effects against CBZ induced hematological and biochemical changes. The results suggest that the attenuation effects of NSSE and FVSE attributed to their antioxidant properties.

Imaging methods used in the assessment of environmental disease networks: a brief review for clinicians

BACKGROUND

Across the globe, diseases secondary to environmental exposures have been described, and it was also found that existing diseases have been modified by exposure to environmental chemicals or an environmental factor that has been found in their pathogenesis. The Institute of Medicine has shared a permanent concern related to the nations environmental health capacity since 1988.

MAIN BODY

Contemporary imaging methods in the last 15 years started reporting alterations in different human systems such as the central nervous system, cardiovascular system and pulmonary system among others; evidence suggests the existence of a human environmental disease network. The primary anatomic regions, affected by environmental diseases, recently assessed with imaging methods include Brain (lead exposure, cerebral stroke, pesticide neurotoxicity), uses MRI, DTI, carotid ultrasonography and MRS; Lungs (smoke inhalation, organophosphates poisoning) are mainly assessed with radiography; Gastrointestinal system (chronic inflammatory bowel disease), recent studies have reported the use of aortic ultrasound; Heart (myocardial infarction), its link to environmental diseased has been proved with carotid ultrasound; and Arteries (artery hypertension), the impairment of aortic mechanical properties has been revealed with the use of aortic and brachial ultrasound.

CONCLUSIONS

Environmental epidemiology has revealed that several organs and systems in the human body are targets of air pollutants. Current imaging methods that can assess the deleterious effects of pollutants includes a whole spectrum: radiography, US, CT and MRI. Future studies will help to reveal additional links among environmental disease networks.

Radiographic pulmonary vessel volume, lung function and airways disease in the Framingham Heart Study

Radiographic abnormalities of the pulmonary vessels, such as vascular pruning, are common in advanced airways disease, but it is unknown if pulmonary vascular volumes are related to measures of lung health and airways disease in healthier populations.In 2388 participants of the Framingham Heart Study computed tomography (CT) sub-study, we calculated total vessel volumes and the small vessel fraction using automated CT image analysis. We evaluated associations with measures of lung function, airflow obstruction on spirometry and emphysema on CT. We further tested if associations of vascular volumes with lung function were present among those with normal forced expiratory volume in 1 s and forced vital capacity.In fully adjusted linear and logistic models, we found that lower total and small vessel volumes were consistently associated with worse measures of lung health, including lower spirometric volumes, lower diffusing capacity and/or higher odds of airflow obstruction. For example, each standard deviation lower small vessel fraction (indicating more severe pruning) was associated with a 37% greater odds of obstruction (OR 1.37, 95% CI 1.11-1.71, p=0.004). A similar pattern was observed in the subset of participants with normal spirometry.Lower total and small vessel pulmonary vascular volumes were associated with poorer measures of lung health and/or greater odds of airflow obstruction in this cohort of generally healthy adults without high burdens of smoking or airways disease. Our findings suggest that quantitative CT assessment may detect subtle pulmonary vasculopathy that occurs in the setting of subclinical and early pulmonary and airways pathology.

Ambient air pollution exposure and risk and progression of interstitial lung abnormalities: the Framingham Heart Study

BACKGROUND

Ambient air pollution accelerates lung function decline among adults, however, there are limited data about its role in the development and progression of early stages of interstitial lung disease.

AIMS

To evaluate associations of long-term exposure to traffic and ambient pollutants with odds of interstitial lung abnormalities (ILA) and progression of ILA on repeated imaging.

METHODS

We ascertained ILA on chest CT obtained from 2618 Framingham participants from 2008 to 2011. Among 1846 participants who also completed a cardiac CT from 2002 to 2005, we determined interval ILA progression. We assigned distance from home address to major roadway, and the 5-year average of fine particulate matter (PM_2.5), elemental carbon (EC, a traffic-related PM_2.5 constituent) and ozone using spatio-temporal prediction models. Logistic regression models were adjusted for age, sex, body mass index, smoking status, packyears of smoking, household tobacco exposure, neighbourhood household value, primary occupation, cohort and date.

RESULTS

Among 2618 participants with a chest CT, 176 (6.7%) had ILA, 1361 (52.0%) had no ILA, and the remainder were indeterminate. Among 1846 with a preceding cardiac CT, 118 (6.4%) had ILA with interval progression. In adjusted logistic regression models, an IQR difference in 5-year EC exposure of 0.14 µg/m³ was associated with a 1.27 (95% CI 1.04 to 1.55) times greater odds of ILA, and a 1.33 (95% CI 1.00 to 1.76) times greater odds of ILA progression. PM_2.5 and O₃ were not associated with ILA or ILA progression.

CONCLUSIONS

Exposure to EC may increase risk of progressive ILA, however, associations with other measures of ambient pollution were inconclusive.

Ambient air pollution and pulmonary vascular volume on computed tomography: the MESA Air Pollution and Lung cohort studies

BACKGROUND

Air pollution alters small pulmonary vessels in animal models. We hypothesised that long-term ambient air pollution exposure would be associated with differences in pulmonary vascular volumes in a population-based study.

METHODS

The Multi-Ethnic Study of Atherosclerosis recruited adults in six US cities. Personalised long-term exposures to ambient black carbon, nitrogen dioxide (NO2), oxides of nitrogen (NO x ), particulate matter with a 50% cut-off aerodynamic diameter of <2.5 μm (PM2.5) and ozone were estimated using spatiotemporal models. In 2010-2012, total pulmonary vascular volume was measured as the volume of detectable pulmonary arteries and veins, including vessel walls and luminal blood volume, on noncontrast chest computed tomography (TPVVCT). Peripheral TPVVCT was limited to the peripheral 2 cm to isolate smaller vessels. Linear regression adjusted for demographics, anthropometrics, smoking, second-hand smoke, renal function and scanner manufacturer.

RESULTS

The mean±sd age of the 3023 participants was 69.3±9.3 years; 46% were never-smokers. Mean exposures were 0.80 μg·m-3 black carbon, 14.6 ppb NO2 and 11.0 μg·m-3 ambient PM2.5. Mean±sd peripheral TPVVCT was 79.2±18.2 cm3 and TPVVCT was 129.3±35.1 cm3. Greater black carbon exposure was associated with a larger peripheral TPVVCT, including after adjustment for city (mean difference 0.41 (95% CI 0.03-0.79) cm3 per interquartile range; p=0.036). Associations for peripheral TPVVCT with NO2 were similar but nonsignificant after city adjustment, while those for PM2.5 were of similar magnitude but nonsignificant after full adjustment. There were no associations for NO x or ozone, or between any pollutant and TPVVCT.

CONCLUSIONS

Long-term black carbon exposure was associated with a larger peripheral TPVVCT, suggesting diesel exhaust may contribute to remodelling of small pulmonary vessels in the general population.

Occupational Exposures and Computed Tomographic Imaging Characteristics in the SPIROMICS Cohort

RATIONALE

Quantitative computed tomographic (CT) imaging can aid in chronic obstructive pulmonary disease (COPD) phenotyping. Few studies have identified whether occupational exposures are associated with distinct CT imaging characteristics.

OBJECTIVES

To examine the association between occupational exposures and CT-measured patterns of disease in the SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study).

METHODS

Participants underwent whole-lung multidetector helical CT at full inspiration and expiration. The association between occupational exposures (self-report of exposure to vapors, gas, dust, or fumes [VGDF] at the longest job) and CT metrics of emphysema (percentage of total voxels < -950 Hounsfield units at total lung capacity), large airways (wall area percent [WAP] and square-root wall area of a single hypothetical airway with an internal perimeter of 10 mm [Pi10]), and small airways (percent air trapping [percent total voxels < -856 Hounsfield units at residual volume] and parametric response mapping of functional small-airway abnormality [PRM fSAD]) were explored by multivariate linear regression, and for central airway measures by generalized estimating equations to account for multiple measurements per individual. Models were adjusted for age, sex, race, current smoking status, pack-years of smoking, body mass index, and site. Airway measurements were additionally adjusted for total lung volume.

RESULTS

A total of 2,736 participants with available occupational exposure data (n = 927 without airflow obstruction and 1,809 with COPD) were included. The mean age was 64 years, 78% were white, and 54% were male. Forty percent reported current smoking, and mean (SD) pack-years was 49.3 (26.9). Mean (SD) post-bronchodilator forced expiratory volume in 1 second (FEV1) was 73 (27) % predicted. Forty-nine percent reported VGDF exposure. VGDF exposure was associated with higher emphysema (β = 1.17; 95% confidence interval [CI], 0.44-1.89), greater large-airway disease as measured by WAP (segmental β = 0.487 [95% CI, 0.320-0.654]; subsegmental β = 0.400 [95% CI, 0.275-0.527]) and Pi10 (β = 0.008; 95% CI, 0.002-0.014), and greater small-airway disease was measured by air trapping (β = 2.60; 95% CI, 1.11-4.09) and was nominally associated with an increase in PRM fSAD (β = 1.45; 95% CI, 0.31-2.60). These findings correspond to higher odds of percent emphysema, WAP, and air trapping above the 95th percentile of measurements in nonsmoking control subjects in individuals reporting VGDF exposure.

CONCLUSIONS

In an analysis of SPIROMICS participants, we found that VGDF exposure in the longest job was associated with an increase in emphysema, and in large- and small-airway disease, as measured by quantitative CT imaging.

Pollution and Global Health – An Agenda for Prevention

Pollution is a major, overlooked, global health threat that was responsible in 2015 for an estimated 9 million deaths and great economic losses. To end neglect of pollution and advance prevention of pollution-related disease, we formed the Lancet Commission on Pollution and Health. Despite recent gains in understanding of pollution and its health effects, this Commission noted that large gaps in knowledge remain. To close these gaps and guide prevention, the Commission made research recommendations and proposed creation of a Global Observatory on Pollution and Health. We posit that successful pollution research will be translational and based on transdisciplinary collaborations among exposure science, epidemiology, data science, engineering, health policy, and economics. We envision that the Global Observatory on Pollution and Health will be a multinational consortium based at Boston College and the Harvard T.H. Chan School of Public Health that will aggregate, geocode, and archive data on pollution and pollution-related disease; analyze these data to discern trends, geographic patterns, and opportunities for intervention; and make its findings available to policymakers, the media, and the global public to catalyze research, inform policy, and assist cities and countries to target pollution, track progress, and save lives. https://doi.org/10.1289/EHP3141.