Associations between ambient particle radioactivity and lung function

Biomarkers of inflammation associated with radon exposure in the School Inner-City Asthma Study (SICAS)

BACKGROUND

Radon is an omnipresent radioactive gas recently reported to be associated with increased asthma morbidity.

OBJECTIVES

We aimed to identify biomarkers associated with radon exposure and hypothesized elevated radon exposure to be associated with increased inflammatory biomarker levels in an exploratory analysis.

METHODS

In 137 schoolchildren with asthma in the School Inner-City Asthma Study, we assessed estimated radon exposure (1-month averaged radon) by a spatiotemporal model and 46 inflammatory biomarker outcomes, adjusting for copollutants (particulate matter with diameter ≤2.5 μm, NO2, O3) and performed mixed-effect regression analysis. Causal mediation analysis was used to determine the association between radon exposure and absolute eosinophil count.

RESULTS

In a total of 137 observations, we found a positive association with radon exposure and IL-5, a TH2-cell cytokine known to recruit eosinophils to asthmatic airways. Higher radon was significantly associated with a greater increase in IL-5 compared to low radon exposure (observations = 137; 1-month moving radon average [% change = 13.4%; 95% CI: 0.4%-28.0%; P = .044]). Mediation analysis revealed an indirect effect of IL-5 (β = 0.006; 95% CI:0.001-0.012; P = .024) on the association between radon exposure and absolute eosinophil count. This suggests the effect of radon on eosinophil count is mediated through IL-5.

CONCLUSIONS

Radon is a potential novel, modifiable risk factor for asthma recently reported to be associated with asthma morbidity. This work identifies important biological disease pathways via biomarkers that may be central to the exposure-outcome relationship.

The Impact of the Indoor Environment on Childhood Asthma

PURPOSE OF REVIEW

This manuscript reviews the impact of important indoor environmental exposures on pediatric asthma, with a focus on recent literature in the field.

RECENT FINDINGS

Studies continue to support an association between numerous indoor aeroallergens and air pollutants found in homes and schools and increased asthma morbidity overall. Several recent home and school intervention studies have shown promise, though results have been overall mixed. Indoor environmental exposures contribute to the development of asthma and impact asthma morbidity. Further research is needed to improve our understanding of how to optimize mitigation of these indoor exposures to significantly affect asthma outcomes.

Ambient beta particle radioactivity and lung cancer survival: Results from the Boston Lung Cancer Study

BACKGROUND

Exposure to ionizing radiation is known to increase the risk of lung cancer. However, studies on the effect of environmental radiation associated with ambient particle air pollution on lung cancer survival are limited. We investigated the association between ambient beta particle radioactivity (PR-β) after a diagnosis and lung cancer survivals.

METHODS

The Boston Lung Cancer Survival (BLCS) cohort consisted of histologically confirmed patients enrolled at Massachusetts General Hospital (MGH) and the Dana-Farber Cancer Institute (DFCI) in Boston, U.S. The primary outcomes included overall survival, 5-year survival, and 3-year survival probability. We estimated ambient PR-β exposure at the ZIP code of residence from 2001 through 2017. Cox-proportional hazards models were constructed to estimate hazard ratios (HRs) for the associations between ambient PR-β and survival outcomes while controlling for covariates.

RESULTS

The analysis included 2795 patients with complete information, with 97,330 person-months of follow-up. The interquartile range (IQR) increase in PR-β was significantly associated with worse overall survival (HR:1.63, 95% CI:1.52, 1.76), 5-year survival (HR:1.33, 95% CI:1.23, 1.44), and 3-year survival (HR:1.22, 95% CI:1.12, 1.33) while adjusting for covariates, including age at diagnosis, sex, race, smoking, stage, histology, and adjusted gross income. Similar associations were found while additionally adjusting for the estimated residential radon exposure. In addition, the survival associated with PR-β exposure was significantly worse for patients in the early stages (HR:2.16, 95% CI:1.84, 2.52).

CONCLUSION

The findings from this study provide new evidence suggesting that environmental exposure to radioactive particles after lung cancer diagnosis may have a pronounced effect on survival, particularly in patients with early stages.

Residential radon decay products are associated with cough and phlegm in patients with COPD

Radon decay products attach to particulate matter (referred to as particle radioactivity, PR) has been shown to be potential to promote airway damage after inhalation. In this study, we investigated associations between PR with respiratory symptoms and health-related quality of life (HRQL) in patients with COPD. 141 male patients with COPD, former smokers, completed the St. George's Respiratory Questionnaire (SGRQ) after up to four 1-week seasonal assessments (N=474) of indoor (home) and ambient (central site) particulate matter ≤ 2.5 µm in diameter (PM2.5) and black carbon (BC). Indoor PR was measured as α-activity (radiation) on PM2.5 filter samples. The ratio of indoor/ambient sulfur in PM2.5 (a ventilation surrogate) was used to estimate α-PR from indoor radon decay. SGRQ responses assessed frequent cough, phlegm, shortness of breath, wheeze, and chest attacks in the past 3 months. Multivariable linear regression with generalized estimating equations accounting for repeated measures was used to explore associations, adjusting for potential confounders. Median (IQR) indoor α-PR was 1.22 (0.62) mBq/m3. We found that there were positive associations between α-PR with cough and phlegm. The strongest associations were with estimated α-PR of indoor origin for cough (31.1 % increase/IQR, 95 %CI: 8.8 %, 57.8 %), and was suggestive for phlegm (13.0 % increase/IQR, 95 %CI: -2.5 %, 31.0 %), similar adjusting for indoor BC or PM2.5. α-PR of indoor origin was positively associated with an increase in SGRQ Symptoms score [1.2 units/IQR; 95 %CI: -0.3, 2.6] that did not meet conventional levels of statistical significance. Our results suggested that exposure to indoor radon decay products measured as particle radioactivity, a common indoor exposure, is associated with cough, and suggestively associated with phlegm and worse HRQL symptoms score in patients with COPD.

Airborne particle radioactivity during desert dust days in Cyprus

Mediterranean countries are often affected by desert dust storms, which have significant effects on the environment and public health. We compared airborne particle radioactivity levels during desert dust and non-dust days in Cyprus. Gross α- and β-radioactivity from Total Suspended Particle (TSP) samples, collected at two urban routine monitoring stations in Limassol and Nicosia, were available for the period 2017-2020 and 2008-2020, respectively. Radionuclides 137Cs and 40K, from TSP samples, were also available from a semi-industrial monitoring station in Nicosia during 2008-2020. Information on desert dust presence, dust origin, particulate matter (PM) levels, and solar activity (KP index and solar sunspot numbers - SSN) were also obtained. We used linear regression models adjusting for seasonality and long-term trends, and solar activity to assess the effect of dust storms on TSP gross α- and β-, and 137Cs and 40K radioactivity levels. Gross α- and β-radioactivity, and 137Cs and 40K radioactivity levels were significantly higher on days with desert dust compared to days characterized with no influence of desert dust. Levels of gross α- and β-radioactivity during dust days were higher when dust originated from the Middle East deserts than from the Sahara Desert. The same trend was observed for the ratios 137Cs to 40K and 137Cs to PM10. Conversely, ratios of TSP gross α- and β-radioactivity to PM10 were significantly lower during desert dust days in comparison to days without dust influence. This study suggests that desert dust increase both TSP gross α- and β-radioactivity, as well as 137Cs and 40K radioactivity levels. Further studies should clarify the contribution of anthropogenic and other natural sources to the emission or transportation of particles radioactivity, to better mitigate future exposures.

Long-term association of air pollution and incidence of lung cancer among older Americans: A national study in the Medicare cohort

BACKGROUND

Despite strong evidence of the association of fine particulate matter (PM2.5) exposure with an increased risk of lung cancer mortality, few studies had investigated associations of multiple pollutants simultaneously, or with incidence, or using causal methods. Disparities were also understudied.

OBJECTIVES

We investigated long-term effects of PM2.5, nitrogen dioxide (NO2), warm-season ozone, and particle radioactivity (PR) exposures on lung cancer incidence in a nationwide cohort.

METHODS

We conducted a cohort study with Medicare beneficiaries (aged ≥ 65 years) continuously enrolled in the fee-for-service program in the contiguous US from 2001 to 2016. Air pollution exposure was averaged across three years and assigned based on ZIP code of residence. We fitted Cox proportional hazards models to estimate the hazard ratio (HR) for lung cancer incidence, adjusted for individual- and neighborhood-level confounders. As a sensitivity analysis, we evaluated the causal relationships using inverse probability weights. We further assessed effect modifications by individual- and neighborhood-level covariates.

RESULTS

We identified 166,860 lung cancer cases of 12,429,951 studied beneficiaries. In the multi-pollutant model, PM2.5 and NO2 exposures were statistically significantly associated with increased lung cancer incidence, while PR was marginally significantly associated. Specifically, the HR was 1.008 (95% confidence interval [CI]: 1.005, 1.011) per 1-μg/m3 increase in PM2.5, 1.013 (95% CI: 1.012, 1.013) per 1-ppb increase in NO2, and 1.005 (0.999, 1.012) per 1-mBq/m3 increase in PR. At low exposure levels, all pollutants were associated with increased lung cancer incidence. Men, older individuals, Blacks, and residents of low-income neighborhoods experienced larger effects of PM2.5 and PR.

DISCUSSION

Long-term PM2.5, NO2, and PR exposures were independently associated with increased lung cancer incidence among the national elderly population. Low-exposure analysis indicated that current national standards for PM2.5 and NO2 were not restrictive enough to protect public health, underscoring the need for more stringent air quality regulations.

Temporal trends of particle gross β-activity and PM2.5 mass concentrations in USA during 2001-2017

This paper investigates the temporal trends of particle gross β-activity (PM-β) and PM2.5 mass in the 50 contiguous United State of America during the period of 2001-2017. With the implementation of stringent air pollution control policies, national ambient PM2.5 concentrations decreased by 38.5% during this period. However, a smaller decrease of 9.4% was observed for PM-β; PM-β is mostly associated with radon emissions, which do not change much with time. The largest PM2.5 and PM-β reductions were observed in the Southeast, while the smallest were found in the West. The overall PM-β to PM2.5 ratio was 0.77 (0.64-0.88; 25th-75th percentile) and was higher when PM2.5 levels were lower. The highest mean PM-β /PM2.5 ratios were found in Wyoming (0.69) and South Dakota (0.51), areas with higher radon, while the mean lowest (0.17) was in Delaware followed by New Jersey (0.18). These results show that there might be toxic, previously unaccounted, components which are still present at low PM2.5 levels.

Radon sampling methodologies: A case for accurate, accessible measurements using household instruments

Radon is a prevalent carcinogenic gas and the leading cause of lung cancer in the United States besides smoking. As the residential environment is the primary source of radon exposure, accessible and accurate measurements of radon in this environment are essential. However, no radon monitors have been evaluated that are inexpensive enough for regular household use. In this study, we examine two household-grade, continuous monitoring devices, the Ecosense RadonEye and EcoQube. We compare them to two research-grade instruments, the Durridge Company Rad7 and the Rad Elec Inc. E-PERM. In our study, the Ecosense household radon monitors performed accurately and can be used by homeowners and researchers alike as an affordable and reliable radon sensor.Implications: The ability of homeowners and renters to regularly monitor the radon levels inside their home is an important preventative health measure. However, low-cost instrumentation is needed that can provide accurate radon measurements. In this study, we show that the affordable Ecosense continuous monitors produce results that are in line with expensive research-grade instruments in a residential environment, over a range of concentrations. The Ecosense monitors may be suitable for home use, and they may provide a solution that can be used by policymakers and home-dwellers alike to improve regular radon monitoring in residences.

The Impact of Metformin on Dust-Induced Histopathological Changes and Oxidative Stress in the Liver: An Insight into Dust Concentration and Liver Biomarkers in Animal Models

Background

Environmental pollution has a profound impact on both human and animal life. Khuzestan province, which has been plagued by intense dust storms and pollution for decades, is the focus of this study. The research aims to investigate the protective effects of metformin against the toxicity of particulate matter in the livers of rats.

Methods

Male Wistar rats were selected for the study and divided into six groups: a control group, Metformin-treated groups, Iraqi dust-exposed group (Iraqi-D), Local dust-exposed group (Local-D), Iraqi dust-exposed with Metformin treatment group (Iraqi-D+Metformin), and Local dust-exposed with Metformin treatment group (Local-D+Metformin). The rats were exposed to local and Iraqi dust through a nebulizer and received oral metformin for a duration of 21 days. At the end of the intervention, liver biomarkers and oxidative stress factors were evaluated enzymatically.

Results

The study revealed that rats exposed to Iraqi and local dust experienced a significant increase in liver biomarkers, including aspartate aminotransferase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALK) levels, alongside a decrease in glutathione (GSH) concentrations and an increase in malondialdehyde (MDA) levels. However, treatment with metformin was effective in preventing the increase in these biomarkers, restoring GSH levels, and averting the rise in MDA levels, as compared to the control group.

Conclusions

Exposure to particulate matter from Iraq and the local region can induce alterations in biomarkers and oxidative stress levels in the rat liver, and these effects can be mitigated through metformin treatment.

Effect of radon exposure on asthma morbidity in the School Inner-City Asthma study

BACKGROUND

Radon may have a role in obstructive lung disease outside its known carcinogenicity. Little is known about radon's effects on asthma morbidity.

OBJECTIVE

To determine the effect of radon on fractional exhaled nitric oxide (FE NO), asthma symptom-days, and lung function in inner-city asthmatic school children.

METHODS

Two hundred ninety-nine school-aged asthmatic children enrolled in the School Inner-City Asthma Study (SICAS-1) were followed. One and two-month averaged radon was assessed using a spatiotemporal model predicting zip code-specific monthly exposures. FE NO and spirometry were measured twice during the academic year. Asthma symptoms were assessed four times during the academic year. The interaction between indoor radon exposure (Bq/m3 ) and seasonality predicting log-transformed FE NO, forced expiratory volume in 1 s (FEV1 ) % predicted, forced vital capacity (FVC) % predicted, FEV1 /FVC, and asthma symptom-days was evaluated.

RESULTS

Participants with high radon exposure had greater change in FE NO from warm to cold periods compared to low radon exposure (interaction p = 0.0013). Participants with >50th percentile radon exposure experience significant FE NO increase from warm to cold weather (β $\beta $  = 0.29 [95% confidence interval [CI]: 0.04-0.54], p = 0.0240). We report a positive association between radon 1-month moving average (incidence rate ratio [IRR] = 1.01, p = 0.0273) and 2-month moving average (IRR = 1.01, p = 0.0286) with maximum asthma symptom-days (n = 299, obs = 1167).

CONCLUSIONS

In asthmatic children, radon may be associated with increased asthma morbidity, suggesting radon may be a modifiable environmental risk factor for airway inflammation.

Prenatal Exposure to Ambient Particle Radioactivity and Fetal Growth in Eastern Massachusetts

Background

The radioactive component of particulate matter (PM), particle radioactivity (PR), can continue to emit radiation after inhalation. While PR has been associated with other adverse pregnancy outcomes, no studies have examined the association with fetal growth.

Methods

Our retrospective cohort included singleton pregnancies that underwent obstetric ultrasounds at an academic medical center in Massachusetts from 2011 through 2016. PR was represented by particle gross β-activity estimated from an ensemble model and was assigned based on residential zip-code. We considered the cumulative (conception until date of fetal growth measurement) and first 16 weeks of gestation PR exposure windows. Standardized z-scores were constructed for biparietal diameter (BPD), head circumference, femur length (FL), abdominal circumference (AC), and birth weight. We used linear mixed regression models adjusted for PM ≤2.5 μm exposure, maternal sociodemographic factors, meteorological variables, and long-term trends.

Results

Among 9,404 pregnancies, an interquartile range increase in cumulative PR exposure was associated with reduced BPD (-0.06 [95% CI: -0.12, -0.01] z-score) and FL (-0.06 [95% CI: -0.12, -0.01] z-score) in scans conducted before 24 weeks' gestation, with increased AC (0.05 [95% CI: 0.01, 0.09]) in scans conducted on or after 24 weeks' gestation, and with lower birth weight (-0.05 [95% CI: -0.11, -0.001] z-score). The first 16 weeks of gestation was not a critical exposure window.

Conclusions

Prenatal PR was associated with fetal growth, with associations generally negative before 24 weeks' gestation and positive later in pregnancy. Our findings bring awareness to a novel environmental exposure.

Particle radioactivity from radon decay products and reduced pulmonary function among chronic obstructive pulmonary disease patients

BACKGROUND

Radon (222Rn) decay products can attach to particles in the air, be inhaled, and potentially cause airway damage.

RESEARCH QUESTION

Is short-term exposure to particle radioactivity (PR) attributable to radon decay products emitted from particulate matter ≤2.5 μm in diameter (PM2.5) associated with pulmonary function in chronic obstructive pulmonary disease (COPD) patients?

STUDY DESIGN AND METHODS

In this cohort study, 142 elderly, predominantly male patients with COPD from Eastern Massachusetts each had up to 4 one-week long seasonal assessments of indoor (home) and ambient (central site) PR and PM2.5 over the course of a year (467 assessments). Ambient and indoor PR were measured as α-activity on archived PM2.5 filter samples. Ratios of indoor/ambient PR were calculated, with higher ratios representing PR from an indoor source of radon decay. We also considered a measure of outside air infiltration that could dilute the concentrations of indoor radon decay products, the indoor/ambient ratio of sulfur concentrations in PM2.5 filter samples. Spirometry pre- and post-bronchodilator (BD) forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were conducted following sampling. Generalized additive mixed models were adjusted for meteorologic variables, seasonality, and individual-level determinants of pulmonary function. We additionally adjusted for indoor PM2.5 and black carbon (BC).

RESULTS

PR exposure metrics indicating radon decay product exposure from an indoor source were associated with a reduction in FEV1 and FVC. Patients in homes with high indoor PR (≥median) and low air infiltration (

INTERPRETATION

Our findings raise concern about the harmful effects of PR exposures attributable to residential radon on pulmonary function in patients with COPD.

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Key Words

• Chronic obstructive pulmonary disease
• Particle radioactivity
• Pulmonary function
• Radiation
• Radon
• Spirometry

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MESH Headings

• Humans
• Male
• Aged
• Female
• Radon Daughters
• Air Pollutants/analysis
• Radioactivity
• Cohort Studies
• Particulate Matter/analysis
• Pulmonary Disease, Chronic Obstructive
• Soot
• Radon
• Environmental Exposure/analysis

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Grants

• R01 ES019853 NIEHS NIH HHS
• R21 ES029637 NIEHS NIH HHS

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Affiliation(s)

Veronica A Wang Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
Petros Koutrakis Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
Longxiang Li Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
Man Liu Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
Carolina L Z Vieira Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
Brent A Coull Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
Edward F Maher Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
Choong-Min Kang Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
Eric Garshick Pulmonary, Allergy, Sleep and Critical Care Medicine Section, Veterans Affairs Boston Healthcare System, Boston, MA, USA; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.

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Collaborators Collapse

Association of high PM2.5 levels with short-term and medium-term lung function recovery in patients with pulmonary lobectomy

The association between exposure to ambient fine particulate matter with an aerodynamic diameter of ≤ 2.5 μm (PM_2.5) and short- and medium-term lung function recovery (LFR) in patients undergoing lobectomy remains uncertain. This study investigated the associations between PM_2.5 concentrations and LFR in adult patients (n = 526) who underwent video-assisted thoracoscopic (VATS) lobectomy in Guangzhou, China between January 2018 and June 2021. All patients underwent at least two spirometry tests. Environmental PM_2.5 concentrations in the same period were collected from the nearest monitoring station. A multiple linear regression (MLR) model was employed to investigate the associations between changes in PM_2.5 concentrations and LFR in patients who underwent lobectomy after adjusting for potential confounders. We assessed short- and medium-term LFR in patients who underwent lobectomy. The three- and 6-month average PM_2.5 concentrations in each patient's residential area were divided into regional mild pollution (PM_2.5 <25 μg/m³), moderate pollution (25 μg/m³ ≤ PM_2.5 <35 μg/m³), and severe pollution (35 μg/m³ ≤ PM_2.5) periods. The MLR model confirmed that PM_2.5 was an independent risk factor affecting short-term forced lung capacity (FVC), forced expiratory volume in 1 s (FEV1), and maximum expiratory flow at 50% vital capacity (MEF₅₀) recovery (adjusted P = 0.041, 0.014, 0.016, respectively). The MLR model confirmed that PM_2.5 was an independent risk factor affecting medium-term MEF₅₀ recovery (adjusted P = 0.046). Compared with the moderate and severe pollution periods, the short- and medium-term LFR (FVC, FEV1, MEF₅₀) of patients in the mild pollution period were faster and better (P < 0.001, P < 0.001, P < 0.001, P = 0.048, P = 0.010, P = 0.013, respectively). Thus, exposure to high PM_2.5 levels was associated with significantly reduced speed and degree of short- and medium-term LFR in patients who underwent lobectomy.

Assessing Exposure to Unconventional Oil and Gas Development: Strengths, Challenges, and Implications for Epidemiologic Research

PURPOSE OF REVIEW

Epidemiologic studies have observed elevated health risks in populations living near unconventional oil and gas development (UOGD). In this narrative review, we discuss strengths and limitations of UOG exposure assessment approaches used in or available for epidemiologic studies, emphasizing studies of children's health outcomes.

RECENT FINDINGS

Exposure assessment challenges include (1) numerous potential stressors with distinct spatiotemporal patterns, (2) critical exposure windows that cover long periods and occur in the past, and (3) limited existing monitoring data coupled with the resource-intensiveness of collecting new exposure measurements to capture spatiotemporal variation. All epidemiologic studies used proximity-based models for exposure assessment as opposed to surveys, biomonitoring, or environmental measurements. Nearly all studies used aggregate (rather than pathway-specific) models, which are useful surrogates for the complex mix of potential hazards. Simple and less-specific exposure assessment approaches have benefits in terms of scalability, interpretability, and relevance to specific policy initiatives such as set-back distances. More detailed and specific models and metrics, including dispersion methods and stressor-specific models, could reduce exposure misclassification, illuminate underlying exposure pathways, and inform emission control and exposure mitigation strategies. While less practical in a large population, collection of multi-media environmental and biological exposure measurements would be feasible in cohort subsets. Such assessments are well-suited to provide insights into the presence and magnitude of exposures to UOG-related stressors in relation to spatial surrogates and to better elucidate the plausibility of observed effects in both children and adults.

Air pollution: A culprit of lung cancer

Air pollution is a global health problem, especially in the context of rapid economic development and the expansion of urbanization. Herein, we discuss the harmful effects of outdoor and indoor pollution on the lungs. Ambient particulate matters (PMs) from industrial and vehicle exhausts is associated with lung cancer. Workers exposed to asbestos, polycyclic aromatic hydrocarbons (PAHs), and toxic metals are also likely to develop lung cancer. Indoors, cooking fumes, second-hand smoke, and radioactive products from house decoration materials play roles in the development of lung cancer. Bacteria and viruses can also be detrimental to health and are important risk factors in lung inflammation and cancer. Specific effects of lung cancer caused by air pollution are discussed in detail, including inflammation, DNA damage, and epigenetic regulation. In addition, advanced materials for personal protection, as well as the current government policies to prevent air pollution, are summarized. This review provides a basis for future research on the relationship between lung cancer and air pollution.

Accumulation of trace element content in the lungs of Sao Paulo city residents and its correlation to lifetime exposure to air pollution

Heavy metals are natural and essential elements of the environment and living beings, produced from natural (e.g. volcanic activity and cosmic ray-induced spallation) and anthropogenic processes (e.g. industrial and fossil fuel combustion). High-concentrations of heavy metals and radionuclides are also originated from anthropogenic activities in urban and industrial areas. In this preliminary study, we analyzed the levels of heavy metals and Polonium-210 (²¹⁰Po) in lung tissues in autopsies from residents of the city of Sao Paulo, SP, Brazil. In order to identify the link among sources of the heavy metals in lungs, factor analysis was performed. Of the first four factors, which explain 66% of the total variability, three were associated with vehicular sources. The fitting of a regression model with ²¹⁰Po as the response variable and with the four factors as explanatory variables, controlling for age, sex and tobacco, showed a significant association between the concentration of polonium and the first factor that is generated by catalysts and brakes (coefficient = 0.90, standard error = 0.33, p = 0.016). Our findings suggest an association between traffic-related trace metals and ²¹⁰Po in lung autopsies.

Health Effects of Natural Environmental Radiation during Burning Season in Chiang Mai, Thailand

This paper presents the first measurement of the investigation of the health impacts of indoor radon exposure and external dose from terrestrial radiation in Chiang Mai province during the dry season burning between 2018 and 2020. Indoor radon activity concentrations were carried out using a total of 220 RADUET detectors in 45 dwellings of Chiang Mai (7 districts) during burning and non-burning seasons. Results show that indoor radon activity concentration during the burning season (63 ± 33 Bq/m3) was significantly higher (p < 0.001) compared to the non-burning season (46 ± 19 Bq/m3), with an average annual value of 55 ± 28 Bq/m3. All values of indoor radon activity concentration were greater than the national (16 Bq/m3) and worldwide (39 Bq/m3) average values. In addition, the external dose from terrestrial radiation was measured using a car-borne survey during the burning season in 2018. The average absorbed rate in the air was 66 nGy/h, which is higher than the worldwide average value of 59 nGy/h. This might be due to the high activity concentrations of 238U and 323Th in the study area. With regards to the health risk assessment, the effective dose due to indoor radon exposure, external (outdoor) effective dose, and total annual effective dose were 1.6, 0.08, and 1.68 mSv/y, respectively. The total annual effective dose is higher than the worldwide average of 1.15 mSv/y. The excess lifetime cancer risk and radon-induced lung cancer risk during the burning season were 0.67% and 28.44 per million persons per year, respectively. Our results substantiate that indoor radon and natural radioactive elements in the air during the burning season are important contributors to the development of lung cancer.

Mortality Attributable to Long-Term Exposure to Ambient Fine Particulate Matter: Insights from the Epidemiologic Evidence for Understudied Locations

Epidemiologic cohort studies have consistently demonstrated that long-term exposure to ambient fine particles (PM_2.5) is associated with mortality. Nevertheless, extrapolating results to understudied locations may involve considerable uncertainty. To explore this issue, this review discusses the evidence for (i) the associated risk of mortality, (ii) the shape of the concentration-response function, (iii) a causal interpretation, and (iv) how the source mix/composition of PM_2.5 and population characteristics may alter the effect. The accumulated evidence suggests the following: (i) In the United States, the change in all-cause mortality risk per μg/m³ is about 0.8%. (ii) The concentration-response function appears nonlinear. (iii) Causation is overwhelmingly supported. (iv) Fossil fuel combustion-related sources are likely more toxic than others, and age, race, and income may modify the effect. To illustrate the use of our findings in support of a risk assessment in an understudied setting, we consider Kuwait. However, given the complexity of this relationship and the heterogeneity in reported effects, it is unreasonable to think that, in such circumstances, point estimates can be meaningful. Consequently, quantitative probabilistic estimates, which cannot be derived objectively, become essential. Formally elicited expert judgment can provide such estimates, and this review provides the evidence to support an elicitation.

A spatiotemporal ensemble model to predict gross beta particulate radioactivity across the contiguous United States

Particulate radioactivity, a characteristic of particulate matter, is primarily determined by the abundance of radionuclides that are bound to airborne particulates. Exposure to high levels of particulate radioactivity has been associated with negative health outcomes. However, there are currently no spatially and temporally resolved particulate radioactivity data for exposure assessment purposes. We estimated the monthly distributions of gross beta particulate radioactivity across the contiguous United States from 2001 to 2017 with a spatial resolution of 32 km, via a multi-stage ensemble-based model. Particulate radioactivity was measured at 129 RadNet monitors across the contiguous U.S. In stage one, we built 264 base learning models using six methods, then selected nine base models that provide different predictions. In stage two, we used a non-negative geographically and temporally weighted regression method to aggregate the selected base learner predictions based on their local performance. The results of block cross-validation analysis suggested that the non-negative geographically and temporally weighted regression ensemble learning model outperformed all base learning model with the smallest rooted mean square error (0.094 mBq/m³). Our model provided an accurate estimation of particulate radioactivity, thus can be used in future health studies.

Effects of particulate matter gamma radiation on oxidative stress biomarkers in COPD patients

Inhalation of particulate matter (PM) radioactivity is an important pathway of ionizing radiation exposure. We investigated the associations between short-term exposures to PM gamma radioactivity with oxidative stress in COPD patients. Urinary concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) of 81 COPD patients from Eastern Massachusetts were measured 1-4 times during 2012-2014. Daily ambient and indoor PM gamma activities (gamma-3 through gamma-9) were calculated based on EPA RadNet data and indoor-outdoor infiltration ratios. Linear mixed-effects models were used to examine the associations between biomarkers with PM gamma activities for moving averages from urine collection day to 7 days before. Our results indicate that ambient and indoor PM gamma activities were positively associated with 8-OHdG, with stronger effects for exposure windows closer to urine collection day. For per interquartile range increase in indoor PM gamma activities averaged over urine collection day and 1 day before, 8-OHdG increased from 3.41% (95% CI: -0.88, 7.88) to 8.87% (95% CI: 2.98, 15.1), adjusted for indoor black carbon. For MDA, the timing of greatest effects across the exposure week varied but was nearly all positive. These findings provide insight into the toxigenic properties associated with PM radioactivity and suggest that these exposures promote systemic oxidative stress.

Sources of indoor PM2.5 gross α and β activities measured in 340 homes

Particle radioactivity (PR) exposure has been linked to adverse health effects. PR refers to the presence of α- and β-emitting radioisotopes attached to fine particulate matter (PM_2.5). This study investigated sources contributing to indoor PM_2.5 gross α- and β-radioactivity levels. We measured activity from long-lived radon progeny radionuclides from archived PM_2.5 samples collected in 340 homes in Massachusetts during the period 2006-2010. We analyzed the data using linear mixed effects models and positive matrix factorization (PMF) analysis. Indoor PM_2.5 gross α-activity levels were correlated with sulfur (S), iron (Fe), bromine (Br), vanadium (V), sodium (Na), lead (Pb), potassium (K), calcium (Ca), silicon (Si), zinc (Zn), arsenic (As), titanium (Ti), radon (²²²Rn) and black carbon (BC) concentrations (p <0.05). Indoor PM_2.5 β-activity was correlated with S, As, antimony (Sb), Pb, Br and BC. We identified four indoor PM_2.5 sources: outdoor air pollution (62%), salt aerosol source (14%), fireworks and environmental tobacco smoke (7%) and indoor mixed dust (17%). Outdoor air pollution was the most significant contributor to indoor PM_2.5 α- and β-activity levels. The contributions of this source were during the summer months and when windows were open. Indoor mixed dust was also found to contribute to PM_2.5 α-activity. PM_2.5 α-activity was further associated with radon during winter months, showing radon's important role as an indoor source of ionizing radiation.

The Role of Ambient Particle Radioactivity in Inflammation and Endothelial Function in an Elderly Cohort

BACKGROUND

The mechanisms by which exposure to particulate matter might increase risk of cardiovascular morbidity and mortality are not fully known. However, few existing studies have investigated the potential role of particle radioactivity. Naturally occurring radionuclides attach to particulate matter and continue to release ionizing radiation after inhalation and deposition in the lungs. We hypothesize that exposure to particle radioactivity increases biomarkers of inflammation.

METHODS

Our repeated-measures study included 752 men in the greater Boston area. We estimated regional particle radioactivity as a daily spatial average of gross beta concentrations from five monitors in the study area. We used linear mixed-effects regression models to estimate short- and medium-term associations between particle radioactivity and biomarkers of inflammation and endothelial dysfunction, with and without adjustment for additional particulate air pollutants.

RESULTS

We observed associations between particle radioactivity on C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1), but no associations with fibrinogen. An interquartile range width increase in mean 7-day particle radioactivity (1.2 × 10 Bq/m) was associated with a 4.9% increase in CRP (95% CI = 0.077, 9.9), a 2.8% increase in ICAM-1 (95% CI = 1.4, 4.2), and a 4.3% increase in VCAM-1 (95% CI = 2.5, 6.1). The main effects of particle radioactivity remained similar after adjustment in most cases. We also obtained similar effect estimates in a sensitivity analysis applying a robust causal model.

CONCLUSION

Regional particle radioactivity is positively associated with inflammatory biomarkers, indicating a potential pathway for radiation-induced cardiovascular effects.

Measurement of the gross alpha activity of the fine fractions of road dust and near-roadway ambient particle matter

Traffic-related air pollution, including direct exhaust emissions and road dust (RD), impacts individuals living near busy roads. We recently conducted a study to investigate the sources and composition of tailpipe and non-tailpipe traffic emissions, where we collected and analyzed samples of ambient air fine particulate matter (PM_2.5) and fine RD (RD_2.5) at different distances from major roadways. We analyzed a subset of the samples, including those collected at the roadside and local background, for their alpha activity level. Subsequently, we investigated whether there is a distance-related decay in the alpha activity in RD_2.5 or PM_2.5 similar to those observed for traffic-related species in PM_2.5 and RD_2.5. We found that the alpha activity of ambient air PM_2.5 (Bq/mg) was more than an order of magnitude higher than the activity level of the corresponding RD_2.5 sample, suggesting that PM_2.5 may be more toxic than RD_2.5. Using mixed-effects regression models, we found that ambient PM_2.5 alpha activity was significantly higher during the cold months than during warm months, and that the background was higher than the roadside (though not significantly). In contrast, the RD_2.5 alpha activity was significantly higher at the background site compared to the roadside but was not significantly affected by season. In addition to sampling position, both Zn and elemental carbon (EC) were significant predictors of RD_2.5 alpha activity. In addition, the roadside RD_2.5 activity levels were found to be higher at highways as compared to secondary roads. While traffic-related emissions do not appear to be significant sources of either ambient PM_2.5 or RD_2.5 alpha activity, the RD_2.5 results suggest that traffic-related particles may contribute to RD_2.5 alpha-activity. Implications: Many studies have reported the effects of traffic-related particulate matter (PM) on human health, and there is growing interest in the health effects of exposure to environmental PM alpha activity. This is the first study to report on the alpha activity of road dust (RD) or near-roadway ambient PM. We found that the alpha activity of ambient PM is twenty times higher than RD, suggesting that ambient PM may be more toxic. In PM and RD, the alpha activities were higher at background sites than at the roadside, indicating that traffic-related emissions are not a significant source of particulate radioactivity.

Same pollution sources for climate change might be hyperactivating the NLRP3 inflammasome and exacerbating neuroinflammation and SARS mortality

We have reviewed a considerable amount of recent scientific papers relating inflammation caused by air pollution with chronic and severe medical conditions. Furthermore, there are evidences relating organ inflammation caused by not only outdoor long-term but also short-term inhaled radioisotopes contained in high polluted air or in household natural radioactive background aerosols, in addition to SARS-COV-2 attached to bioaerosols, which are related with a worst evolution of severe acute respiratory syndrome patients. Reactive oxygen species (ROS) production induced by the interaction with environmental ionizing radiation contained in pollution is pointed out as a critical mechanism that predispose mainly to elder population, but not excluding young subjects, presenting previous chronic conditions of lung inflammation or neuroinflammation, which can lead to the most serious consequences.

Unconventional oil and gas development and ambient particle radioactivity

Unconventional oil and natural gas development (UOGD) expanded extensively in the United States from the early 2000s. However, the influence of UOGD on the radioactivity of ambient particulate is not well understood. We collected the ambient particle radioactivity (PR) measurements of RadNet, a nationwide environmental radiation monitoring network. We obtained the information of over 1.5 million wells from the Enverus database. We investigated the association between the upwind UOGD well count and the downwind gross-beta radiation with adjustment for environmental factors governing the natural emission and transport of radioactivity. Our statistical analysis found that an additional 100 upwind UOGD wells within 20 km is associated with an increase of 0.024 mBq/m³ (95% confidence interval [CI], 0.020, 0.028 mBq/m³) in the gross-beta particle radiation downwind. Based on the published health analysis of PR, the widespread UOGD could induce adverse health effects to residents living close to UOGD by elevating PR.

Measurements of Gross α- and β-Activities of Archived PM2.5 and PM10 Teflon Filter Samples

The adverse effects of ambient particulate matter (PM) on human health have been well demonstrated, but the underlying properties responsible for its toxicity are still unclear. We hypothesized that particulate radioactivity, which is due to the attachment of radioactive nuclides on particle surfaces, may be responsible for part of PM toxicity. We measured the gross α- and β-activities for daily PM_2.5 and PM₁₀ filters collected at the Harvard Supersite in downtown Boston from 2005 to 2006 and calculated the radioactivities at the time of air sampling retrospectively based on a previously established formula. We examined the relationship between different radioactivities and compared our measurements to those measured at the Boston EPA RadNet Station. The results showed that the majority of PM₁₀ radioactivity is associated with that of PM_2.5 samples for both α-activity (98%) and β-activity (83%). A strong linear relationship was observed between the α- and β-activities for both PM_2.5 [slope = 0.47 (±0.03); p-value < 0.0001] and PM₁₀ [slope = 0.46 (±0.09); p-value < 0.0001] samples. Measurements at the Harvard Supersite and at EPA RadNet sites are highly correlated for both α-activities [slope = 0.17 (±0.02), p-value < 0.0001] and β-activities [slope = 0.30 (±0.05), p-value < 0.0001]. Additionally, we identified several significant predictors for PM_2.5 α-activities. This novel method we developed to measure α- and β-activities from archived filters will make it possible to assess the retrospective particle radioactivity exposure for future epidemiological studies.

Ambient particle radioactivity and gestational diabetes: A cohort study of more than 1 million pregnant women in Massachusetts, USA

BACKGROUND

Exposure to ionizing radiation increases the risk of chronic metabolic disorders such as insulin resistance and type 2 diabetes. Internal ionizing radiation from inhaled radioactive aerosol may contribute to the associations between fine particulate matter (PM_2.5) and gestational diabetes mellitus (GDM).

METHODS

We used the Massachusetts Registry of Vital Records to study 1,061,937 pregnant women from 2001 to 2015 with a singleton pregnancy without pre-existing diabetes. Gross β activity measured by seven monitors of the U.S. Environmental Protection Agency's RadNet monitoring network was utilized to represent ambient particle radioactivity (PR). We obtained GDM status from birth certificates and used logistic regression analyses adjusted for socio-demographics, maternal comorbidities, PM_2.5, temperature and relative humidity. We also examined effect modification by smoking habits.

RESULTS

Ambient particle radioactivity exposure during first and second trimester of pregnancy was associated with higher odds of GDM (OR: 1.18 (95% CI 1.10 to 1.22). Controlling for PM_2.5 did not substantially change the effects of PR on GDM. In women that reported being former or current smokers, the association between PR and GDM was null. In the full cohort, the overall effect of PM_2.5 on GDM without adjusting for PR was not significant.

CONCLUSION

This is the first population-based study to examine the association between particle radioactivity and gestational diabetes mellitus - one of the most common pregnancy-related diseases with lifelong effects for the mother and the fetus. This finding has important public health policy implications because it enhances our understanding about the toxicity of PR, a modifiable risk factor, which to date, has been considered only as an indoor and occupational air quality risk.

Spanish translation and psychometric evaluation of the Healthcare Professional Knowledge of Radiation Protection scale

The objective of this work was to make an intercultural adaptation and provide a Spanish translation and psychometric evaluation of the original English version of the Healthcare Professional Knowledge of Radiation Protection (HPKRP) scale. The Spanish translation was carried out following international guidelines for the process of cross-cultural adaptation of self-report measures. A cross-sectional design study was carried out. One hundred and thirty-eight nurses from four different hospitals in Barcelona (Spain) completed the Spanish version of the scale. The total score of the scale was calculated. The Pearson correlation coefficient (PCC) was used to evaluate a possible correlation between score and years of experience. A t-test for independent samples was used to evaluate significant differences between different groups. Cronbach's alpha, the corrected item-total correlation coefficient and the test-retest coefficient were used to determine internal consistency. The exploratory factor and parallel analysis were also calculated. All statistical tests were carried out with a level of significance α = 0.05. The mean scale score was poor among Spanish nurses. The PCC between total score and years of experience showed a non-significant correlation (p > 0.05). No differences were found between nurses who worked in radiation-exposed units and those who worked in units without radiation exposure (p > 0.05). A Cronbach α of 0.98 was obtained for the items of the scale. The corrected item-total correlation range was 0.5-0.8. The test-retest correlation coefficient was 0.9. The exploratory analysis factor showed a single factorial structure which explained 60.86% of the variance. The new scale translated into Spanish (Sp-HPKRP) could be used to evaluate the degree of knowledge about radiological protection.

Short-term exposure to ambient particle gamma radioactivity is associated with increased risk for all-cause non-accidental and cardiovascular mortality

BACKGROUND

Recent studies have found that particulate matter (PM) attached radioactivity was associated with certain adverse health effects including increased blood pressure and lung dysfunction. However, there has been no investigation on the direct effect of PM radioactivity on mortality.

METHODS

Exposures to ambient PM gamma activities were determined using U.S. EPA RadNet data. Data on daily deaths were obtained from individual state Departments of Public Health. We used a generalized additive quasi-Poisson model to estimate the associations between two-day average ambient PM gamma activities (gamma2 through gamma9) with all-cause non-accidental and cardiovascular daily deaths for each of 18 US cities, for each season, adjusting for two-day average PM_2.5 exposure, temperature, relative humidity, day of week and long-term trends. Subsequently, we used random-effects meta-analysis to estimate the overall effect in the 18 cities for each season.

RESULTS

We found that all-cause non-accidental daily mortality in spring season was positively associated with two-day average ambient PM gamma activities in spring, with significant results for gamma2, gamma5 and gamma6. Similarly, cardiovascular daily mortality was positively associated with two-day average ambient PM gamma activities, with significant results for gamma2, gamma4, gamma5, gamma6, gamma7 and gamma9. For the spring season, each interquartile range (IQR) increase of two-day averaged ambient PM gamma activity was associated with increase in all-cause daily deaths, ranging from 0.15% (95% Confidence Interval (CI): -0.36%, 0.65%) to 1.03 (95%CI: 0.18%, 1.89%). Each IQR was also associated with increase in cardiovascular daily deaths, ranging from 0.01% (95%CI: -0.89, 0.92) to 2.95% (95%CI: 1.33, 4.59). For other seasons overall we found statistically insignificant associations of PM radioactivity with mortality.

CONCLUSIONS

Our findings suggest that there are potential systemic toxic effects of inhalation of radionuclides attached to ambient air particles.

Exposure to Particle Beta Radiation in Greater Massachusetts and Factors Influencing Its Spatial and Temporal Variability

Particle radioactivity is a property of airborne particles caused by the presence of naturally occurring or anthropogenic radionuclides. Recent studies have found associations between particle radioactivity and adverse health outcomes, including changes in blood pressure and lung function. However, the spatiotemporal distribution of particle radioactivity and factors influencing its variability have not been extensively studied. We address these knowledge gaps using measurements of gross beta activity, collected at seven Environmental Protection Agency (EPA) RadNet monitors located in and around Massachusetts. We apply back-trajectory analysis to identify prevailing air mass trajectories and find that these trajectories strongly influence seasonal trends in beta activity. We also evaluate the effects of different meteorological predictors on daily beta activity concentrations using a mixed-effect model. Important predictors of beta activity include air mass trajectories, temperature, and relative humidity. Finally, we create a series of random forest models to impute missing beta activity concentrations at each RadNet monitor for use in future health studies. This is the first study to analyze spatiotemporal trends in particle radioactivity using measurements from the EPA RadNet system.

Maternal exposure to fine particle matters cause autophagy via UPR-mediated PI3K-mTOR pathway in testicular tissue of adult male mice in offspring

Epidemiological studies have shown that particulate matters are closely related to human infertility. However, the long-term risk of particulate matters exposure in early life is rarely considered. For the first time this study is designed to explore and elucidate the mechanism of maternal exposure to fine particle matters (PM_2.5) on autophagy in spermatogenic cells of adult offspring. Pregnant C57BL/6 mice were randomly divided into four groups. The 4.8 mg/kg.b.w group and the 43.2 mg/kg.b.w group were administered with different doses of PM_2.5. The membrane control group was administered with PM_2.5 sampling membrane and the control group received no treatment. The exposure was performed every three days from the day after vaginal plug was checked until delivery for a total of 6 times. The results showed that sperms motility and sperms concentration decreased, and sperm deformity increased in adult male offspring. The expression of SOD decreased and MDA increased. Moreover, the level of GRP78/ATF6 and P62 was upregulated, and the expression of PI3K/Akt/mTOR/p-mTOR was down-regulated. This suggests that early-life exposure to PM_2.5 can induce autophagy through the PI3K/Akt/mTOR pathway mediated by unfolded protein response in adult testicular tissue. PM_2.5 may pose a significant role and long-term threat to adult after early-life exposure.