Levels of PM10 and PM2.5 and Respiratory Health Impacts on School-Going Children in Kenya

Airborne Particulate Matter Size and Chronic Obstructive Pulmonary Disease Exacerbations: A Prospective, Risk-Factor Analysis Comparing Global Initiative for Obstructive Lung Disease 3 and 4 Categories

Current research primarily emphasizes the generalized correlations between airborne pollution and respiratory diseases, seldom considering the differential impacts of particular particulate matter sizes on chronic obstructive pulmonary disease (COPD) exacerbations in distinct Global Initiative for Obstructive Lung Disease (GOLD) categories. This study hypothesizes a critical association between particulate matter sizes (PM 1.0, PM 2.5, and PM 10) and exacerbation frequency in COPD patients categorized under GOLD 3 and GOLD 4, with a potential augmenting role played by proximity to main roads and industrial areas. This research aspires to offer a nuanced perspective on the exacerbation patterns in these groups, setting the stage for targeted intervention strategies. Utilizing a prospective design, this study followed 79 patients divided into GOLD 3 (n = 47) and GOLD 4 (n = 32) categories. The participants were monitored for ten days for daily activity levels, symptoms, living conditions, and airborne particulate matter concentrations, with spirometric evaluations employed to measure lung function. Statistical analyses were used to identify potential risk factors and significant associations. The analysis revealed substantial disparities in airborne particulate matter sizes between the two groups. The mean PM 1.0 concentration was notably higher in GOLD 4 patients (26 µg/m3) compared to GOLD 3 patients (18 µg/m3). Similarly, elevated PM 2.5 levels were observed in the GOLD 4 category (35 µg/m3) in contrast to the GOLD 3 category (24 µg/m3). A vital finding was the increased frequency of exacerbations in individuals residing within 200 m of main roads compared to those living further away (OR = 2.5, 95% CI: 1.5-4.1). Additionally, patients residing in homes smaller than 50 square meters demonstrated a greater frequency of exacerbations. Spirometry results corroborated the exacerbated condition in GOLD 4 patients, indicating a significant decline in lung function parameters compared to the GOLD 3 group. This study substantiates a significant association between airborne particulate matter sizes and exacerbation frequencies in COPD patients, particularly accentuating the increased risk in GOLD 4 patients. Our findings underscore the pivotal role of environmental factors, including the size of living areas and proximity to main roads, in influencing COPD exacerbations. These results suggest the need for personalized healthcare strategies and interventions, which account for environmental risk factors and the distinctions between GOLD 3 and GOLD 4 categories of COPD patients.

Exposure to indoor and outdoor air pollution in schools in Africa: Current status, knowledge gaps, and a call to action

Chronic exposure to indoor and outdoor air pollution is linked to adverse human health impacts worldwide, and in children, these include increased respiratory symptoms, reduced cognitive and academic performance, and absences from school. African children are exposed to high levels of air pollution from aging diesel and gasoline second-hand vehicles, dusty roads, trash burning, and solid-fuel combustion for cooking. There is a need for more empirical evidence on the impact of air pollutants on schoolchildren in most countries of Africa. Therefore, we conducted a scoping review on schoolchildren's exposure to indoor and outdoor PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 μm and PM10 (particulate matter with an aerodynamic diameter less than 10 μm) in Africa. Following PRISMA guidelines, our search strategy yielded 2975 records, of which eight peer-reviewed articles met our selection criteria and were considered in the final analysis. We also analyzed satellite data on PM2.5 and PM10 levels in five African regions from 1990 to 2019 and compared schoolchildren's exposure to PM2.5 and PM10 levels in Africa with available data from the rest of the world. The findings showed that schoolchildren in Africa are frequently exposed to PM2.5 and PM10 levels exceeding the recommended World Health Organization air quality guidelines. We conclude with a list of recommendations and strategies to reduce air pollution exposure in African schools. Education can help to produce citizens who are literate in environmental science and policy. More air quality measurements in schools and intervention studies are needed to protect schoolchildren's health and reduce exposure to air pollution in classrooms across Africa.

A case study on occupational exposure assessment and characterization of particles in a printing shop in China

Printers can release numerous particles to contaminate indoor environments and pose health risks. Clarifying the exposure level and physicochemical properties of printer-emitted particles (PEPs) will help to evaluate the health risks of printer operator. In our study, the particles concentration in the printing shop was monitored in real time for a long time (12 h/day, total 6 days), and the PEPs were collected to characterize their physicochemical properties including shape, size and compositions. The result showed that the concentration of PEPs is closely related to the printing workload and the highest particle mass concentration of PM₁₀ and PM_2.5 was 212.73 μg m^-3 and 91.48 μg m^-3, respectively. The concentration of PM₁ in the printing shop was in the range of 11.88-80.59 μg m^-3 for mass value, and 174.83-1348.84 P cm^-3 for count value which changed with the printing volume. The particle sizes of PEPs were less than 900 nm, 47.99% of PEPs was less than 200 nm, and 14.21% of the particles were at the nanoscale. PEPs contained 68.92% organic carbon (OC), 5.31% elemental carbon (EC), 3.17% metal elements, and 22.60% other inorganic additives, which contained more OC and metal elements than toners. Total polycyclic aromatic hydrocarbons (PAHs) levels were 18.95 ng/mg in toner and 120.70 ng/mg in PEPs. The carcinogenic risk of PAHs in PEPs was 1.40 × 10^-7. These findings suggested future studies should pay more attention to the health effects of printing workers exposed to nanoparticles.

Saharan Dust and Childhood Respiratory Symptoms in Benin

Mineral dust is one of the largest natural constituents of coarse particulate matter (PM₁₀). Most of these dust emissions originate from northern Africa, and several hundred tera-grams of dust are emitted annually from this region. Previous evidence has linked dust PM₁₀ to adverse respiratory outcomes in children. However, most of these studies have been from high-income countries (HICs) or examined dust from other regions of the world, mainly Asia. Evidence from low-to-middle-income countries (LMICs) in Africa is scarce. Respiratory infections are one of the leading causes of under-five mortality across the globe. However, there is a poignant disparity in studies examining these outcomes in children in the region where most dust is emitted. This study linked remotely sensed satellite data to a nationally representative survey to examine acute exposure to dust in children living in Benin using a time-stratified case-crossover analysis. We identified acute effects of exposure to dust and increased risk of cough in children under five. The effect of increased risk is strongest within two weeks of exposure and dissipates by four weeks. Children living in rural areas and households with lower income had a greater risk of adverse respiratory outcomes when exposed to dust. We could elucidate the specific period and conditions of increased risk for respiratory problems in children living in Benin.