Airborne Particulate Matter Pollution Research Articles

Occupational Dust Exposure as a Risk Factor for Developing Lung Function Impairment.

Dust exposure is high in several industries. We investigated associations of exposure in paper mills, wood pellet plants, and iron foundries with lung function impairment. Respirable silica, inhalable paper dust, or inhalable wood dust were collected as personal samples and spirometry was performed. Multiple linear regression analyzed associations with FEV 1 %pred and FVC%pred. Wood pellet workers with high exposure to inhalable dust had lower FEV 1 %pred (95% CI) (-9.4 [-16 to -2.6]) and FVC%pred (-9.8 [-15 to -4.0]) compared with lowest exposure level. Workers at paper mills and foundries had no dose-dependent association but lower FEV 1 %pred and FVC%pred than in workers at wood pellets plants. Increased exposure to inhalable wood dust is associated with decreased lung function. Foundry and paper mill workers have generally lower lung function than wood pellet workers. Spirometry should be considered in workers in industries with airborne particulate matter pollution.

Dual-Network Structured Nanofibrous Membranes with Superelevated Interception Probability for Extrafine Particles.

Airborne particulate matter (PM) pollution has caused a public health threat, including nanoscale particles, especially with emerging infectious diseases and indoor and vehicular environmental pollution. However, most existing indoor air filtration units are expensive, energy-intensive, and bulky, and there is an unavoidable trade-off between low-efficiency PM0.3/pathogen interception, PM removal, and air resistance. Herein, we designed and synthesized a two-dimensional continuous cellulose-sheath/net with a unique dual-network corrugated architecture to manufacture high-efficiency air filters and even N95 particulate face mask. Combined with its sheath/net structured pores (size 100-200 nm) consisting of a cellulose framework (1-100 nm diameter), the cellulose sheath/net filter offers high-efficiency air filtration (>99.5338%, Extrafine particles; >99.9999%, PM2.5), low-pressure drops, and a robustness quality factor of >0.14 Pa-1, utilizing their ultralight weight of 30 mg/m2 and physical adhesion and sieving behaviors. Simultaneously, masks prepared with cellulose-sheath/net filters are more likely to capture and block smaller particles than the N95 standard. The synthesis of such materials with their nanoscale features and designed macrostructures may suggest new design criteria for a novel generation of high-efficiency air filter media for different applications such as personal protection products and industrial dust removal.

Lactoferrin attenuated urban particulate matter-induced nephrotoxicity by regulating the CSF2/CENPE axis

Several epidemiological studies regarding the adverse effect of air pollution have notably accelerated in recent years. Urban particulate matter (PM) gains access to the respiratory system and translocates into the circulation to affect several tissues, such as the liver and kidneys. Lactoferrin is a substance belonging to the non-heme iron-binding glycoprotein which is present in breast milk and other exocrine fluids. Lactoferrin is protective against many pathophysiological conditions. In the present study, we explored the potential influence of lactoferrin on PM-induced nephrotoxicity. We found that lactoferrin rescued PM-induced cell death but did not affect apoptosis in human kidney cells. Lactoferrin decreased necroptosis and fibrosis but increased autophagy in human kidney cells. Furthermore, the gene expression profiles of PM and lactoferrin were analyzed by RNA sequencing. The transcriptional profiles were uploaded and analyzed by ingenuity pathway analysis software and gene set enrichment analysis. The results showed that the crucial role of the CSF2/CENPE pathway was involved in human kidney cells treated with PM and lactoferrin. In a mouse model, lactoferrin ameliorates PM-induced nephrotoxicity by regulating necroptosis, fibrosis, autophagy and the CSF2/CENPE axis. In summary, these findings showed that lactoferrin could be a novel therapeutic or preventive agent for renal disorders caused by airborne PM pollution.

Micro-morphological analysis of foliar uptake and retention of airborne particulate matter (PM)-bound toxic metals: implications for their phytoremediation

ABSTRACT While airborne particulate matter (PM) pollution is a serious problem for urban environments, it can be reduced through uptake by plant leaves. In this study, we investigated and compared the uptake of PM-bound toxic metals by different plant species. Enrichment factor (EF) and correlation analyses across different sample types indicated anthropogenic origins of these toxic metals with airborne source signatures. Scanning electron microscopy (SEM) analyses of both leaf surfaces (adaxial and abaxial) suggested that the micro-morphological properties of the leaf surface (e.g. stomata, trichomes, epicuticular wax, and epidermal appendages) control the accumulation of PM and associated metals in plant leaves. Senna siamea leaves showed the most micro-morphological variation as well as the maximum concentration of toxic metals. It was found that foliar uptake of PM-bound toxic metals is affected by leaf surface morphological characteristics. Our results imply that plant speciation strategies can be used to help decrease PM pollution.

Air Pollution, Political Corruption, and Cardiovascular Disease in the Former Soviet Republics.

Background:Ambient air pollution is a serious problem in many Eastern European countries. Elevated levels of fine airborne particulate matter (PM2.5) pollution in the former Soviet republics relative to the rest of Europe contribute to elevated rates of disease, especially cardiovascular disease (CVD).Objective:Information on the underlying social and political causes of air pollution in Eastern Europe is important for pollution control and disease prevention.Methods:To quantify relationships between pollution, and air-pollution-related CVD, and political corruption throughout Europe and particularly in the former Soviet republics, we relied on the State of Global Air report for information on air pollution levels; on the 2019 Global Burden of Disease study (GBD) for estimates of the burden of air-pollution-related CVD; and on Transparency International (TI) for rankings of governmental corruption.Findings:Air-pollution-related CVD was responsible for an estimated 178,000 (UI: 112,000–251,000) premature deaths and for the loss of 4,010,000 (UI: 2,518,000–-5,611,000) productive years of life (DALYs) in 2019 in the former Soviet republics. A significant positive correlation (R = 0.72, p 1.7e–8) was found across Europe between air-pollution-related CVD mortality rates and national corruption rankings.Conclusions:We conclude that lack of governmental transparency, inadequate air pollution monitoring, and opposition by vested interests have hindered air pollution control and perpetuated high rates of pollution-related morbidity and mortality in the former Soviet republics. Ending corruption and modernizing industrial production will be key to air pollution and related diseases.

Research on mitochondrial oxidative stress accompanying the diabetic process under airborne particulate matter pollution by NIR fluorescence imaging of cysteine

Complex airborne particulate matter (APM) pollution seriously destroys the redox balance of organisms. Diabetes is a chronic disorder of the redox system, and its progression is usually accompanied by mitochondrial oxidative stress. The role of cysteine (Cys) in the process of mitochondrial oxidative stress is crucial as an essential scavenger of reactive oxygen species. Consequently, it is of great value to investigate the link between mitochondrial oxidative stress and diabetes by measuring changes in mitochondrial cysteine levels. However, it has not been revealed how the levels of Cys change in the mitochondria during diabetes. Therefore, we designed a novel mitochondria-targeted near-infrared fluorescent probe to assay cysteine. Importantly, by using the new probe, we discovered that mitochondrial Cys levels were significantly decreased in the diabetic cells and mice. We also uncovered that a dramatic reduction of Cys levels in the mice exposed to the presence of excess particulate matter from environmental pollution, for the first time. These findings will provide valuable insights into new treatments for diabetes and offer a practical tool to unravel the connection between mitochondrial oxidative stress and associated diseases. We believe this research will help experts to better understand the role of Cys under the APM threat.

Necroptosis contributes to airborne particulate matter-induced ocular surface injury

In this study, we explored the role of necroptosis in the pathogenesis of ocular surface injury caused by airborne particulate matter (PM). Human corneal epithelial (HCE) cells and mouse ocular surface were treated with PM exposure and compared with non-exposed groups. The expression of necroptosis-related proteins was measured by immunoblotting in HCE cell groups. Cell damages were detected using CCK-8, flow cytometry, and immunofluorescence staining. In the mouse model, hematoxylin and eosin (H&E) staining and corneal fluorescein sodium staining were assessed. In addition, the expression of inflammatory cytokines and mucin were examined via Enzyme-linked immunosorbent assay (ELISA), immunofluorescence staining and/or quantitative RT -PCR (qRT-PCR), both in vitro and in vivo. Our research showed that PM exposure may trigger HCE cell damage via necroptosis. Necrostatin-1(Nec-1), one of the specific inhibitors of necroptosis, can markedly reduce PM-induced HCE cell damage. HCE cell damage markers included decreased cell viability, increased intracellular reactive oxygen species (ROS) levels, and loss of mitochondrial membrane potential. At the same time, Nec-1 inhibited the increased inflammatory cytokines and the decreased mucin expression caused by PM exposure in HCE cells. Nec-1 also reduced corneal inflammation and mucin underproduction in mouse ocular surface after PM exposure. Our study demonstrated that necroptosis is involved in the pathogenesis of PM exposure-related ocular surface injury, including inflammation and insufficient mucin production in the cornea, which can be rescued by inhibitor Nec-1. This suggests Nec-1 could be a novel therapeutic target for ocular surface disorders, especially dry eye disease, which is caused by the exacerbation of airborne PM pollution.

Piezoelectric Nanofiber Membrane for Reusable, Stable, and Highly Functional Face Mask Filter with Long‐Term Biodegradability

AbstractThe emergence of the SARS‐CoV‐2 pandemic and airborne particulate matter (PM) pollution has led to remarkably high demand for face masks. However, conventional respirators are intended for single use and made from nondegradable materials, causing serious concern for a plastic‐waste environmental crisis. Furthermore, these facemasks are weakened in humid conditions and difficult to decontaminate. Herein, a reusable, self‐sustaining, highly effective, and humidity‐resistant air filtration membrane with excellent particle‐removal efficiency is reported, based on highly controllable and stable piezoelectric electrospun poly (l‐lactic acid) (PLLA) nanofibers. The PLLA filter possesses a high filtration efficiency (>99% for PM 2.5 and >91% for PM 1.0) while providing a favorable pressure drop (≈91 Pa at normal breathing rate) for human breathing due to the piezoelectric charge naturally activated by respiration through the mask. The filter has a long, stable filtration performance and good humidity resistance, demonstrated by a minimal declination in the filtration performance of the nanofiber membrane after moisture exposure. The PLLA filter is reusable via common sterilization tools (i.e., an ultrasonic cleaning bath, autoclave, or microwave). Moreover, a prototype of a completely biodegradable PLLA nanofiber‐based facemask is fabricated and shown to decompose within 5 weeks in an accelerated degradation environment.

Source Apportionment and Risk Estimation of Heavy Metals in PM10 at a Southern Vietnam Megacity

Airborne particulate matter (PM) pollution is a global concern, in which partitioned heavy metals (HMs) could impose great risks to residents living in metropolitan areas. In this study, PM10 samples were collected in Ho Chi Minh City (HCMC) – a megacity in southern Vietnam – and analyzed for 11 HMs to investigate their concentration profiles, perform source apportionment and estimate their risk factors. Results showed that atmospheric HMs concentration decreased following the order of Al > Fe > Sr > Mn> Pb > Cu > Cr > V > Ni > Sb > As. Traffic activities were likely the major cause of rush-hour peaks for most HMs in which Cr, As, and Cu showed > 20% increases in their relative proportions. For seasonal variation, most HMs showed a dry > rainy pattern as a result of washout by higher rainfall in the rainy season while crustal elements (Al, Sr, Mn) showed a rainy > dry pattern and might be explained by the difference in air mass transport modulating by monsoon activities. The positive-matrix factorization (PMF) model revealed 5 primary sources for HMs, including traffic emission, shipping activity and combustion activity, fugitive dust re-suspension and waste incineration. Combustion activity might enrich As, Sb, Pb levels at HCMC, and As contributed half (50.8%) to the potential ecological risk (PER) in the city. Besides, the current Cr level could impose a carcinogenic effect towards children in HCMC (total carcinogenic index > 10-4) while Mn might impose intolerable non-carcinogenic risk (hazard index > 1). This study provides information on local air quality status for scientific and regulatory perspectives as well as helps fill the information gap and update the understanding of air pollution in South and Southeast Asia.

A Study of the Correlation between the Concentration of Particulate Matter and Green Area Ratio Measured through a Portable Monitoring System: With Particular Focus on the Case of Dalseo-Gu, Daegu Metropolitan City

This study analyzed the relationship between the measured concentration of particulate matter (PM) and green area, which is an important spatial factor affecting urban PM concentration and even more carbon neutral in cities. In order to investigate the effects of green area, the green area ratio (GAR) is used and correlated with particulate matter. As a result of analyzing the correlation between GAR and PM concentration using the measured PM data, it was found that there was a positive correlation between the two variables. Hence, the higher the GAR, the lower the PM concentration. It can be said that the introduction of spatial elements with high GAR scores, such as parks and forests in cities, is effective in reducing PM concentration. In this study, a portable PM monitoring system using a vehicle for PM measurement was also established and operated. As a result, it was found that a PM monitoring system using a light-scattering sensor is an effective PM measurement method that can be used at the local government level. It was also found that a follow-up study is needed in the future to identify the PM mitigation functions of urban green areas according to the detailed characteristics of green areas as well as various environmental factors. This study can be used in air quality improvement activities and efforts as reference data by policy decision makers and in the field of environmental planning associated with the removal of airborne particulate matter pollution in urban areas.

Airborne particulate matter in an iron mining city: Characterization, cell uptake and cytotoxicity effects of nanoparticles from PM2.5, PM10 and PM20 on human lung cells

Airborne particulate matter (PM) is dispersed into the atmosphere and can internalize in the lungs during the respiratory process by passive exposure. Itabira city (Minas Gerais, Brazil) is a mining city with relevant PM emissions derived from iron exploitation, transport, and processing. In the present study, the PM2.5, PM10, and PM20 characterization from iron ore and its internalization and cytotoxicity effects were evaluated in the MRC-5 human lung cell line. PMs were characterized using scanning electron microscopy with EDS and X-ray analysis and, then, dispersed in water and analyzed by Dynamic Light Scattering and Nanosight techniques. Flow cytometry was applied to evaluate PM cellular uptake on MRC-5 cells and death induction. The results demonstrate that the PM10 mass collected were higher than those reported by the local governmental agencies and the PMs are mainly constituted by hematite and quartz. EDS analysis showed the presence of Fe, Si, Mg, Al, Zi, Ca, and emerging metallic contaminants, such as Ba and Ti, in environmental samples. Analyzed PM samples dissociate into nanoparticles (< 200 nm) in aqueous medium, demonstrating that the PM comprises aggregated nanoparticles that can be internalized in cells, leading to a decrease in cell viability. Thus, reducing PM exposure may be considered as a potential tool for reducing metal contaminants in the air and respiratory diseases. In view of the health and environmental problems caused by airborne PM pollution, this study brings new discussions aiming to improve safety standards and future investigations in this field worldwide.

Micro/nanofibrous nonwovens with high filtration performance and radiative heat dissipation property for personal protective face mask

The COVID-19 pandemic and airborne particulate matter (PM) pollution have posed a great threat to human health. Personal protective face masks have become an indispensable protective equipment in our daily lives. However, wearing conventional face masks for a long time cause swelter and discomfort on the face. Introducing thermal comfort into personal protective face masks becomes desirable. Herein, face masks that show excellent filtration performance and radiative heat dissipation effect are successfully designed and prepared by electrospining Nylon-6 (PA) nanofibers onto polyethylene (PE) meltblown nonwovens. The resultant PE/PA nonwovens have high PM filtration efficiency (>99%) with a low pressure drop (<100 Pa). Moreover, taking the advantage of the property of PE, the designed face mask posses high mid-infrared (mid-IR) transmittance and brings about high radiative cooling power, resulting in effective heat dissipation performance. This face mask design may provides new insights into the development of thermal comfort materials for personal protection.

Airborne Particulate Matter Pollution in Akure Metro City, Southwestern Nigeria, West Africa: Attribution and Meteorological Influence

We investigated the origin, seasonal air quality indices (AQI), and the likely fate of particulate matters (PM10 and PM2.5) across Akure, a metro capital city in the Niger Delta region of Nigeria. The analysis included the contributions of meteorological properties to the distribution of the particulates, especially fugitive dust. We observed that the PM concentrations exhibited significant differences in the differential, spatial, and temporal patterns. During the wet season, the air movement zones were turbulence, interception, and divergence, whereas only the interception zone was observed in the dry season. For the wet season, the average daily PM2.5 and PM10 concentrations (in ppm) varied from 7 to 62 and 11 to 85, respectively, while, the respective daily mean concentrations ranged from 11 to 63 and 17 to 86. Furthermore, the fine/coarse ratio (PM2.5/PM10) ranged 0.63–0.83 and 0.65–0.73 during the wet and dry seasons, respectively, with 90% of the ratio being ≈0.70. The statistical t-value for PM10, PM2.5, and AQI were 0.60, 0.61, and 0.45, respectively, while their corresponding P-values were 0.56, 0.55, and 0.66, indicating no significant seasonal variations. Overall, Akure’s air quality is majorly influenced by environmental conditions (based on anthropogenic activities) and merely by meteorological conditions. Conclusively, to achieve sustainable development, enforced environmental management that involves green and blue economies as the panacea to atmospheric pollution in Akure should be implemented.

Study on the Characteristics of Size-Segregated Particulate Water-Soluble Inorganic Ions and Potentially Toxic Metals during Wintertime in a High Population Residential Area in Beijing, China

Airborne particulate matter (PM) pollution often occurs in the wintertime in northern China, posing a potential threat to human health. To date, there are limited studies about the metals and inorganic ions to link source apportionments and health risk assessments in the different size-segregated PM samples. In this study, our samples were collected by a high-volume air sampler from 26 December 2018 to 11 January 2019 in a high population residential area (Beijing). Water-soluble inorganic ions, metal elements in the different size-segregated PM samples were determined for health risk assessments by inhalation of PM. During the sampling period in Beijing, the average concentrations of PM1.1 and PM1.1–2.0 were 39.67 ± 10.66 μg m−3 and 32.25 ± 6.78 μg m−3. Distinct distribution profiles characterized the different elements. The markers of coal combustion Pb, As, and Se had &gt;52% of their mass concentration in PM1.1. The average mass ratios of (NO3− + NO2−)/SO42−, Cl−/Na+, Cl−/K+, and Cl−/(NO3− + NO2−) were 1.68, 6.58, 6.18, and 0.57, which showed that coal combustion and vehicle emissions were the main anthropogenic sources of PM in Beijing in winter. PM1.1 was the major contributor of Pb, Cd, and As for carcinogenic risks (CR) and hazard quotient (HQ). It was indicated that PM1.1 is more harmful than coarse PM. The toxic elements of Cr (VI) (1.12 × 10−6), V (0.69 × 10−6), and As (0.41 × 10−6) caused higher CR for children than Ni, Cd, Co, and Pb. Meanwhile, Pb (35.30 × 10−6) and Ni (21.07 × 10−6) caused higher CR for adults than As, Cr (VI), V, Co, and Cd, especially PM1.1. This study provides detailed composition data and the first report on human health in a high population residential area in Beijing.

ЗАБРУДНЕННЯ АЕРОЗОЛЬНИМИ ЧАСТИНКАМИ, ЩО ПОВ'ЯЗАНЕ З ЕКСПОРТОМ ФОСФАТУ У ПОРТУ АННАБА

For several decades, airborne particulate matter (PM) pollution has become one of the major concerns of policymakers across the globe, due to its adverse effects on climate, human health, environment and various socio-economic sectors. The process of phosphate export in bulk is one of the main source generating air pollutants, such as PM emissions of different shapes, concentrations and particle sizes, which can cause respiratory diseases. The objective of this work is to determine the dust level generated by the processes of unloading, storage and loading of phosphate in bulk to ships, by the company of the port installation at the port of Annaba (East of Algeria). The PM measurement campaign was carried out according to the NF X 43-014. It was performed on 08 sampling points located at the port of Annaba and in a periphery with a radius of up to 2.3 km. The recorded results show very high levels of dust in 05 samples series largely exceeding the acceptable threshold (1000 mg/m²/day). The level of heavy metals in dust was evaluated by the analysis of Atomic Absorption Spectrometry. EDAX analysis showed that the phosphate PM have an angular morphology elongated particles and hook-shaped.

Monitoring uranium mine pollution on Native American lands: Insights from tree bark particulate matter on the Spokane Reservation, Washington, USA

The uranium boom in the United States from the 1940's to the 1980's was a period of extensive uranium mining on Native American lands. However, detailed environmental investigations of the resulting uranium pollution are sparse and typically ignore contributions from airborne particulate matter. The Midnite Mine is a 350-acre inactive open pit uranium mine located on the Spokane Indian Reservation in eastern Washington that operated from 1954 to 1981. Approximately 2.4 million tons of ore and 33 million tons of waste rock were left behind in stockpiles and have also been utilized as gravel on access and haul roads. Although the Midnite Mine is now a Superfund Site, and governmental investigations of water and soil contamination have been done, no investigations of airborne particulate matter pollution have been conducted. This study applies tree bark from 31 Pinus ponderosa trees as a biomonitor of this airborne particulate matter. Bulk trace elemental analyses via inductively coupled plasma – mass spectrometry (ICP-MS) of tree bark show that U is the most abundant trace element of interest present up to 232 ppb. Other metals that are of potential human health concern include Th, Pb, and As which are present at 20 ppb, 104 ppb, and 20 ppb respectively. Calculated geoaccumulation indices determine these metals to be at high (U), moderate (Th), and low (Pb and As) levels of contamination. Detailed scanning electron microscopy (SEM) investigations of particulate matter from the surface of tree bark confirm that U and Th-bearing particulate matter exist in the <PM10 size fraction while geospatial analyses indicate that uranium, thorium, and arsenic contamination are centralized along the Midnite Mine access road and at the nearby Dawn Mill where ore was further processed. Combined, these findings indicate that the nature and distribution of historic airborne particulate matter from the Midnite Mine and Dawn Mill provide context for potentially understanding past and current illness on the reservation. In addition, much needed context for future health and environmental studies for both local and national Native American populations is provided.

A systematic review of the leaf traits considered to contribute to removal of airborne particulate matter pollution in urban areas.

Global urban planning has promoted green infrastructure (GI) such as street trees, shrubs or other greenspace in order to mitigate air pollution. Although considerable attention has been paid to understanding particulate matter (PM) deposition on GI, there has been little focus on identifying which leaf traits might maximise airborne PM removal. This paper examines existing literature to synthesize the state of knowledge on leaf traits most relevant to PM removal. We systematically reviewed measurement studies that evaluated particulate matter accumulated on leaves on street trees, shrubs green roofs, and green walls, for a variety of leaf traits. Our final selection included 62 papers, most from field studies and a handful from wind tunnel studies. The following were variously promoted as useful traits: coniferous needle leaves; small, rough and textured broadleaves; lanceolate and ovate shapes; waxy coatings, and high-density trichomes. Consideration of these leaf traits, many of which are also associated with drought tolerance, may help to maximise PM capture. Although effective leaf traits were identified, there is no strong or consistent evidence to identify which is the most influential leaf trait in capturing PM. The diversity in sampling methods, wide comparison groups and lack of background PM concentration measures in many studies limited our ability to synthesize results. We found that several ancillary factors contribute to variations in the accumulation of PM on leaves, thus cannot recommend that selection of urban planting species be based primarily on leaf traits. Further research into the vegetation structural features and standardization of the method to measure PM on leaves is needed.

Quantifying the Deposition of Airborne Particulate Matter Pollution on Skin Using Elemental Markers.

Airborne particulate matter (PM) pollution is an environmental and health concern. The health impact of PM pollution has typically focused on the respiratory system. The impact of PM pollution on skin has been largely understudied due to the lack of a quantitative method to measure the deposition on skin. This manuscript presents a method to quantify PM pollution on skin using elemental markers as a proxy for PM. Skin tape strips were collected from forehead and buttock of 100 outdoor workers in Beijing, China. Skin samples were analyzed for 19 elemental markers using inductively coupled plasma mass spectrometry. To determine the specific elemental signature of PM for the region, air samples were collected over 7 days for PM < 2.5 μm (PM2.5) and analyzed for the same 19 elements as the skin samples. An enrichment factor was calculated for each element and the potential source was evaluated. Using the elemental markers unique to PM pollution for the region, the PM concentration deposited on skin was determined to be 0.621-2.53 μg PM2.5 /cm2. This method can be re-applied in different regions and the PM concentration on skin can inform future studies on the health impact of air pollution on skin.

Airborne particulate matter, population mobility and COVID-19: a multi-city study in China

BackgroundCoronavirus disease 2019 (COVID-19) is an emerging infectious disease, which has caused numerous deaths and health problems worldwide. This study aims to examine the effects of airborne particulate matter (PM) pollution and population mobility on COVID-19 across China.MethodsWe obtained daily confirmed cases of COVID-19, air particulate matter (PM2.5, PM10), weather parameters such as ambient temperature (AT) and absolute humidity (AH), and population mobility scale index (MSI) in 63 cities of China on a daily basis (excluding Wuhan) from January 01 to March 02, 2020. Then, the Generalized additive models (GAM) with a quasi-Poisson distribution were fitted to estimate the effects of PM10, PM2.5 and MSI on daily confirmed COVID-19 cases.ResultsWe found each 1 unit increase in daily MSI was significantly positively associated with daily confirmed cases of COVID-19 in all lag days and the strongest estimated RR (1.21, 95% CIs:1.14 ~ 1.28) was observed at lag 014. In PM analysis, we found each 10 μg/m3 increase in the concentration of PM10 and PM2.5 was positively associated with the confirmed cases of COVID-19, and the estimated strongest RRs (both at lag 7) were 1.05 (95% CIs: 1.04, 1.07) and 1.06 (95% CIs: 1.04, 1.07), respectively. A similar trend was also found in all cumulative lag periods (from lag 01 to lag 014). The strongest effects for both PM10 and PM2.5 were at lag 014, and the RRs of each 10 μg/m3 increase were 1.18 (95% CIs:1.14, 1.22) and 1.23 (95% CIs:1.18, 1.29), respectively.ConclusionsPopulation mobility and airborne particulate matter may be associated with an increased risk of COVID-19 transmission.

Airborne Particulate Matter Pollution—Knowledge, Perception and Breathing Experiences of Port Harcourt Residents During COVID-19 Pandemic Shutdown

While millions of deaths are recorded from COVID-19 pandemic infection, the environment continues to benefits from the lockdown of cities. A descriptive cross-sectional survey aimed at assessing residents’ knowledge and perception concerning air pollution and breathing experience in Port Harcourt was carried out within 20th-28th of May, 2020. Convenience and purposive non-randomized sampling methods were used to recruit 358 participants. Using descriptive and chi square test analysis, majority (74% and 24%) of the respondents were very aware or aware of air pollution and its health consequences. This varied significantly with sex, age, marital status, occupation and location (p &lt; 0.05). Before the city’s lockdown, 90.1% of respondents experienced particulate matter deposits on surfaces and during the lockdown; it reduces to 54.1% with significant difference (p &lt; 0.05) across residential areas. Hence, age, sex, marital status, occupation and residential area likely to influence higher awareness of air pollution and not duration of stay. Also, significant difference in breathing experiences (p &lt; 0.05) was noted, with majority reporting poor breathing experience before lockdown and good during the lockdown. Joint action of governments’ policies on air pollution and high awareness among residents could be explored effectively to mitigate air pollution hazards.