Household air pollution and adult respiratory health

Genetic evidence for the causal effects of air pollution on the risk of respiratory diseases

BACKGROUND

Epidemiological studies have consistently demonstrated a robust association between long-term exposure to air pollutants and respiratory diseases. However, establishing causal relationships remains challenging due to residual confounding in observational studies. In this study, Mendelian randomization (MR) analysis was used to explore the causal and epigenetic relationships between various air pollutants and common respiratory diseases.

METHODS

We utilized a two-sample Mendelian randomization (TSMR) approach to explore the impact of PM2.5, PM2.5-10, PM10, NO2, and NOX on the incidence of nine respiratory diseases using data from large-scale European GWAS datasets (N = 423,796-456,380 for exposures; N = 162,962-486,484 for outcomes). The primary analytical method was inverse variance weighting (IVW), which explored the exposure-outcome relationship using single nucleotide polymorphisms (SNPs) associated with air pollution. Sensitivity analyses, including MR-Egger regression and leave-one-out analyses, were employed to ensure result consistency. Multivariate MR (MVMR) was performed to adjust for potential smoking-related confounders, such as cigarettes per day, household smoking, exposure to tobacco smoke at home, ever smoked, second-hand smoke, smoking initiation, and age at smoking initiation, as well as the independent effects of each air pollutant. Additionally, methylation and enrichment analyses were conducted to further elucidate the potential effects of air pollution on respiratory diseases.

RESULTS

TSMR analysis revealed that exposure to PM2.5 increased the risk of early-onset chronic obstructive pulmonary disease (COPD), pneumonia, pulmonary embolism and lung cancer. PM2.5-10 exposure was associated with an increased risk of lung cancer, while PM10 exposure increased the risk of pneumonia and bronchiectasis. NO2 exposure was associated with increased risks of lung cancer and adult asthma. Importantly, these associations remained robust even after controlling for potential tobacco-related confounders in the MVMR analyses. In the MVMR analysis adjusting for other pollutants, significant associations persisted between PM2.5 and early-onset COPD, and between PM10 and pneumonia. Genetic co-localization analyses confirmed that methylation of PM2.5-associated CpG loci (cg11386376 near c1orf175, cg11846064 near rfx2, cg18612040 near rptor, and cg19765378 near c7orf50) was associated with an increased risk of early-onset COPD. Finally, SNPs significantly associated with exposure and outcome were selected for enrichment analysis.

CONCLUSIONS

Our findings suggest that exposure to air pollutants may play a causal role in the development of respiratory diseases, with a potential role of epigenomic modifications emphasized. Strengthening comprehensive air pollution regulations by relevant authorities could potentially mitigate the risk of these diseases.

Environmental house calls can reduce symptoms of chemical intolerance: a demonstration of personalized exposure medicine

AIM

The goals of this investigation were to 1) identify and measure exposures inside homes of individuals with chemical intolerance (CI), 2) provide guidance for reducing these exposures, and 3) determine whether our environmental house calls (EHCs) intervention could reduce both symptoms and measured levels of indoor air contaminants.

BACKGROUND

CI is an international public health and clinical concern, but few resources are available to address patients' often disabling symptoms. Numerous studies show that levels of indoor air pollutants can be two to five (or more) times higher than outdoor levels. Fragranced consumer products, including cleaning supplies, air fresheners, and personal care products, are symptom triggers commonly reported by susceptible individuals.

METHODS

A team of professionals trained and led by a physician/industrial hygienist and a certified indoor air quality specialist conducted a series of 5 structured EHCs in 37 homes of patients reporting CI.

RESULTS

We report three case studies demonstrating that an appropriately structured home intervention can teach occupants how to reduce indoor air exposures and associated symptoms. Symptom improvement, documented using the Quick Environmental Exposure and Sensitivity Inventory Symptom Star, corresponded with the reduction of indoor air volatile organic compounds, most notably fragrances. These results provide a deeper dive into 3 of the 37 cases described previously in Perales et al. (2022).

DISCUSSION

We address the long-standing dilemma that worldwide reports of fragrance sensitivity have not previously been confirmed by human or animal challenge studies. Our ancient immune systems' 'first responders', mast cells, which evolved 500 million years ago, can be sensitized by synthetic organic chemicals whose production and use have grown exponentially since World War II. We propose that these chemicals, which include now-ubiquitous fragrances, trigger mast cell degranulation and inflammatory mediator release in the olfactory-limbic tract, thus altering cerebral blood flow and impairing mood, memory, and concentration (often referred to as 'brain fog'). The time has come to translate these research findings into clinical and public health practice.

Air Pollutants Removal Using Biofiltration Technique: A Challenge at the Frontiers of Sustainable Environment

Air pollution is a central problem faced by industries during the production process. The control of this pollution is essential for the environment and living organisms as it creates harmful effects. Biofiltration is a current pollution management strategy that concerns removing odor, volatile organic compounds (VOCs), and other pollutants from the air. Recently, this approach has earned vogue globally due to its low-cost and straightforward technique, effortless function, high reduction efficacy, less energy necessity, and residual consequences not needing additional remedy. There is a critical requirement to consider sustainable machinery to decrease the pollutants arising within air and water sources. For managing these different kinds of pollutant reductions, biofiltration techniques have been utilized. The contaminants are adsorbed upon the medium exterior and are metabolized to benign outcomes through immobilized microbes. Biofiltration-based designs have appeared advantageous in terminating dangerous pollutants from wastewater or contaminated air in recent years. Biofiltration uses the possibilities of microbial approaches (bacteria and fungi) to lessen the broad range of compounds and VOCs. In this review, we have discussed a general introduction based on biofiltration and the classification of air pollutants based on different sources. The history of biofiltration and other mechanisms used in biofiltration techniques have been discussed. Further, the crucial factors of biofilters that affect the performance of biofiltration techniques have been discussed in detail. Finally, we concluded the topic with current challenges and future prospects.

Impact of Air Pollution on Global Burden of Disease in 2019

Air pollution consisting of ambient air pollution and household air pollution (HAP) threatens health globally. Air pollution aggravates the health of vulnerable people such as infants, children, women, and the elderly as well as people with chronic diseases such as cardiorespiratory illnesses, little social support, and poor access to medical services. This study is aimed to estimate the impact of air pollution on global burden of disease (GBD). We extracted data about mortality and disability adjusted life years (DALYs) attributable to air pollution from 1990 to 2019. The extracted data were then organized and edited into a usable format using STATA version 15. Furthermore, we also estimated the impacts for three categories based on their socio-demographic index (SDI) as calculated by GBD study. The impacts of air pollution on overall burden of disease by SDI, gender, type of pollution, and type of disease is estimated and their trends over the period of 1990 to 2019 are presented. The attributable burden of ambient air pollution is increasing over the years while attributable burden of HAP is declining over the years, globally. The findings of this study will be useful for evidence-based planning for prevention and control of air pollution and reduction of burden of disease from air pollution at global, regional, and national levels.

Fractional exhaled nitric oxide (FeNO) in students in Northern Thailand: associations with respiratory symptoms, diagnosed allergy and the home environment

OBJECTIVE

There are few studies on fractional exhaled nitric oxide (FeNO) among children in subtropical areas. We studied associations between FeNO and respiratory symptoms, reported diagnosed allergies and indoor and outdoor environmental factors in first grade junior high school students (N = 270) in upper northern Thailand.

METHODS

Data on demographics, health and home environment were collected by a questionnaire distributed in dry season (February-March 2018). FeNO was measured when the research team visited the school. Daily outdoor pollution data (PM₁₀ and ozone) were collected from the nearest monitoring station 3 days (lag 3) and 7 days (lag 7) before the FeNO measurements. Two-level (student, school) linear mixed models were used to analyze associations, adjusting for gender and family education level.

RESULTS

In total, 29.6% had elevated FeNO level (>20 ppb) and 7.8% reported any allergy diagnosed by a doctor. Male gender (p = 0.02), diagnosed allergy (p = 0.001), especially to cat (p = 0.001) and house dust mite (HDM) allergies (p = 0.001) were associated with FeNO. Eye symptoms (p = 0.01), rhinitis symptoms (p = 0.03) and dyspnea (p = 0.05) in the last 3 days were associated with FeNO. Household indoor mold (p = 0.03), gas cooking (p = 0.03) and PM₁₀ (lag 3 and lag 7) were negatively (protective) associated with FeNO.

CONCLUSIONS

Diagnosed allergy, especially to cat and HDM, can be associated with increased FeNO. Indoor mold and gas cooking can be associated with lower FeNO. Ocular, nasal and dyspnea symptoms reported by students in dry season in northern Thailand can be associated with FeNO, a biomarker of Th2 driven airway inflammation.