Exposure to bioaerosols at open dumpsites: A case study of bioaerosols exposure from activities at Olusosun open dumpsite, Lagos Nigeria

ABPA and AFRS: addressing prevalence, early diagnosis, allergens, and occupational concerns

OBJECTIVE

This study aimed to comprehensively investigate the prevalence of ABPA and AFRS, scrutinize existing diagnostic criteria and immunoassays, pinpoint their limitations, highlight ABPA as an occupational health implication, and identify suggestive measures to improve ABPA diagnosis in the context of Occupational Health Nursing and primary healthcare.

DATA SOURCES

The data sources such as PubMed, Health and Safety Science Abstracts, OSH Update, Medline, and Google Scholar were searched.

STUDY SELECTIONS

All published studies in the English language from 1990 till Oct, 2023 using Mesh terms keywords "Allergic bronchopulmonary aspergillosis," "Allergic fungal rhinosinusitis," "Signs and Symptoms," "Rapid Diagnostic Tests," "Diagnosis," "Occupational Health," "Occupational Health Nursing," "Prevalence," "Allergens" following "Boolean operators" search strategy were selected.

RESULTS

This review succinctly covered signs, symptoms, and prevalence data concerning ABPA and AFRS. It briefly discussed existing diagnostic criteria and immunoassays, highlighted factors influencing the assay's variability, and underscored the role and scope of specific allergens toward improved, simple, and early ABPA diagnosis. ABPA as a neglected occupational health concern was emphasized, and the importance of RDTs in the context of healthcare professionals and OHNs was stated. Finally, this study suggested analyzing the impact of compromised post-pandemic immune status and the use of immunosuppressive drugs on ABPA prevalence among vulnerable communities and occupations.

CONCLUSION

To conclude, global and Indian ABPA and AFRS prevalence data, factors influencing existing assay variability, and the scope of improvement in RDTs for ABPA diagnosis in the background of primary healthcare professionals and OHNs were addressed.

Characteristics and health implications of fine particulate matter near urban road site in Islamabad, Pakistan

The escalating issue of air pollution has become a significant concern in urban regions, including Islamabad, Pakistan, due to the rise in air pollutant emissions driven by economic and industrial expansion. To gain a deeper understanding of air pollution, a study was conducted during winter 2022-2023, assessing physical, chemical, and biological factors in Islamabad. The findings revealed that the average concentration of fine particulate matter (PM2.5) was notably greater than the World Health Organization (WHO) guidelines, reaching 133.39 μg/m³. Additionally, the average concentration of bacteria (308.64 CFU/m³) was notably greater than that of fungi (203.55 CFU/m³) throughout the study. Analytical analyses, including SEM-EDS and FTIR, showed that the PM2.5 in Islamabad is composed of various particles such as soot aggregates, coal fly ash, minerals, bio-particles, and some unidentified particles. EF analysis distinguished PM2.5 sources, enhancing understanding of pollutants origin, whereas Spearman's correlation analysis elucidated constituent interactions, further explaining air quality impact. The results from the Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES) indicated a gradual increase in the total elemental composition of PM2.5 from autumn to winter, maintaining high levels throughout the winter season. Furthermore, a significant variation was found in the mass concentration of PM2.5 when comparing samples collected in the morning and evening. The study also identified the presence of semi-volatile organic compounds (SVOCs) in PM2.5 samples, including polycyclic aromatic hydrocarbons (PAHs) and phenolic compounds, with notable variations in their concentrations. Utilizing health risk assessment models developed by the US EPA, we estimated the potential health risks associated with PM2.5 exposure, highlighting the urgency of addressing air quality issues. These findings provide valuable insights into the sources and composition of PM2.5 in Islamabad, contributing to a comprehensive understanding of air quality and its potential environmental and health implications.

Tracking bioaerosol exposure among municipal solid waste workers using hematological and inflammatory biomarkers

High levels of bioaerosols may exist in the air of municipal solid waste (MSW) management facilities, constituting a significant occupational hazard for workers. In this study, we investigated the potential association between exposure to bioaerosols and inflammatory biomarkers among municipal solid waste workers (MSWWs) at both the landfill site and the municipal solid waste transfer station (MSWTS), in comparison to a control group without exposure. Air sampling was conducted at six points around the landfill, two points at the MSWTS, and one point in a public park (as a control area) during the spring and summer of 2019. The results of our study revealed that airborne pathogens were highly prevalent at the sampling points, especially in the active zone and leachate collection pond. Aspergillus species were the predominant fungal species detected in this study, with the highest occurrence observed for Aspergillus flavus (83.3%), Aspergillus niger, and Aspergillus fumigatus (75.0%). Furthermore, Staphylococcus species accounted for over 75% of the total bacterial bioaerosols detected across all study areas. The blood test results of workers revealed a significant increase in platelets (PLT), immunoglobulin G (IgG), white blood cells (WBC), neutrophils, basophils, and high-sensitivity C-reactive protein (hs-CRP) compared to the control group. Conversely, platelet distribution width (PDW), mean platelet volume (MPV), and platelet-large cell ratio (P-LCR) in the exposed subjects exhibited a decreasing trend compared to the control group. These findings suggest a potential association between exposure to bioaerosols, particularly in the vicinity of open dumpsites, and elevated levels of hematologic and inflammatory markers in circulation. Furthermore, the influence of smoking status and confounding factors appears to be significant in both the control and exposure groups.

The global distribution of epidemiological studies involving waste pickers: A systematic review

Waste pickers, who work with the collection of recyclable materials in search of a source of income, are subject to various risks and diseases that are very well researched. The aim of this systematic review was therefore to identify and analyze the results of epidemiological research on waste pickers over the last 20 years as well as to investigate the geographical distribution and quality of these studies. The studies were selected from the literature by creating search keys with representative keywords in different databases. This systematic review exceptionally includes research qualified according to the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. In total, 61 epidemiological studies with waste pickers were found in 15 different countries, with the largest number of studies carried out in the American continent compared to the African and Asian, respectively. Regarding the quality, 91.80 % were classified as excellent and 8.20 % as good. Although the results show a significant number of epidemiological studies with waste pickers, demonstrating scientific evidence, that there is still a lack of research focusing on waste pickers in different work scenarios, from different health perspectives and in different parts of the world, and it is not possible to highlight the trends in health research for this profession.

Systematic review and meta-analysis of the potential threats to respiratory health from microbial Bioaerosol exposures

Infectious diseases are a part of everyday life, and acute respiratory diseases are the most common. Many agents carrying out respiratory infections are transmitted as bioaerosols through the air, usually, particulate matter containing living organisms. The purpose of the study is to conduct a systematic review and meta-analysis to assess the likelihood that people exposed to bioaerosols may experience severe respiratory diseases. Nine digital databases and bibliographies were assessed for papers conducted between January 1960 and April 2021. A total of 35 health and exposure studies were included from 825 studies for the systematic review, while only 17 contented the meta-inclusion analysis's criteria. This systematic review found higher bacterial bioaerosol concentrations in poultry farms, waste dumpsites, composting plants, and paper industries. The meta-analysis's Standard Mean Difference (SMD) measurement indicates a substantially positive association between bioaerosol exposure and respiratory disease outcomes in targeted populations. The value is 0.955 [95% CI, range 0.673-1.238; p < 0.001]. As per the Risk of Bias (ROB) findings, most of findings (30 out of 35 [85.71%]) were judged to have low ROB. From the random effect probit model, the total relative risk is 1.477 (95% CI, range 0.987-2.211), indicating a higher risk of respiratory diseases from bioaerosol exposure than the control groups. The total risk difference is 0.121 (95% CI, -0.0229 to 0.264), which means intervention groups may have a higher risk of respiratory diseases from continuous bioaerosol exposure than the control groups. The dose-response relationship revealed a strong positive linear coefficient correlation between bacterial & fungal bioaerosol exposure to respiratory health. Based on self-reported outcomes in those studies, The systematic review and meta-analysis stated that bioaerosol exposure had an effect on pulmonary health.

Review of bioaerosols from different sources and their health impacts

The emission of bioaerosols in the ambient atmosphere from different sources is a cause of concern for human health and the environment. Bioaerosols are a combination of biotic matter like microbes and pollens. The present review emphasizes the understanding of various sources of bioaerosols (industries, municipal solid waste, and medical facilities), their components, and their impact on human health. The study of bioaerosols is of great importance as large numbers of people are estimated to be exposed on the global scale. Bioaerosols exposure in different work environments results in health issues such as infectious diseases, allergies, toxic effects, and respiratory problems. Hence, extensive research is urged to establish an effective assessment of bioaerosols exposure in the workplace, risks involved, distribution, and validation. The present review is intended to explore the relationship between bioaerosols exposure to the atmosphere and its impacts on human health. Some of the preliminary findings, based on our analysis of bioaerosols arising from municipal solid waste at a landfill site and a waste transfer station in Hyderabad, India, are also discussed herein.

Passive fungal spore release from fruit and vegetable solid waste

Food substrates in municipal solid wastes processing facilities and open dumpsites are a source for the release of fungal spores into air and can cause potential health and climate effects. Experiments were conducted in a laboratory scale flux chamber to measure the fungal growth and spore release from representative exposed cut fruit and vegetable substrates. The aerosolised spores were measured using an optical particle sizer. The results were compared to experiments conducted previously with a test species (Penicillium chrysogenum) on a synthetic media (czapek yeast extract agar). Significantly higher surface spore densities were observed for the fungi on the food substrates as compared to that on the synthetic media. The spore flux was high initially and then decreased on continued exposure to air. The spore emission flux normalised to the surface spore densities indicated that the emission from the food substrates was lower than the emissions from the synthetic media. A mathematical model was applied to the experimental data and the observed flux trends were explained in terms of the model parameters. A simple application of the data and the model to release from a municipal solid waste dumpsite was shown.

Municipal solid waste management with recyclable potential in developing countries: Current scenario and future perspectives

Municipal solid waste (MSW) is a complex challenge to be solved worldwide, intensified in developing countries since in addition to economic and environmental aspects there is also the social aspect represented by the collector individual. From an integrative bibliographic review this study longitudinally analyses the socio-productive inclusion of collectors in the municipal solid waste management (MSWM) at an international level. Aiming: (a) to identify relevant articles describing/studies on MSWM with social inclusion of scavengers around the world; (b) to analyse these articles in order to present its main characteristics; (c) to describe municipal solid waste management with recyclable potential (MSWRP) with socio-productive inclusion of collectors; (d) the study provides a more detailed summary of MSWRP management in some developing countries: Brazil, China, India, Indonesia, Mexico, Nigeria and Pakistan; and (e) to provide a framework indicating the future practices and perspectives of MSWRP. As result, this study presents the paradigms and future questions for an effective improvement of WSWM, such as: Professional Training of Scavengers, Cultural Issues, Empowerment of Scavenger, Recycling Cooperatives and Cooperativism, Policy Issues and Recycling Chain, Management Systems and Process Improvement, Quality of Services Provided, Circular Economy and Informal Sector, Health Quality and Safety at Work, Barriers and Solutions for the Inclusion of the Informal Sector, Environmental, Economic and Social Benefits.

Bio-fabricated bismuth-based materials for removal of emerging environmental contaminants from wastewater

Although rapid industrialization has made life easier for humans, several associated issues are emerging and harming the environment. Wastewater is regarded as one of the key problems of the 21st century due to its massive production every year and requires immediate attention from all stakeholders to protect the environment. Since the introduction of nanotechnology, bismuth-based nanomaterials have been used in variety of applications. Various techniques, such as hydrothermal, solvo-thermal and biosynthesis, have been reported for synthesizing these materials, etc. Among these, biosynthesis is eco-friendly, cost-effective, and less toxic than conventional chemical methods. The prime focuses of this review are to elaborate biosynthesis of bismuth-based nanomaterials via bio-synthetic agents such as plant, bacteria and fungi and their application in wastewater treatment as anti-pathogen/photocatalyst for pollutant degradation. Besides this, future perspectives have been presented for the upcoming research in this field, along with concluding remarks.

Informal E-waste recycling practices and environmental pollution in Africa: What is the way forward?

Globally, e-waste is the fastest growing and most valuable waste-stream. While countries worldwide are increasingly acknowledging the e-waste problem and introducing policies and regulations that deal with e-waste, large quantities of e-waste still go undocumented. Much of these global e-wastes are accumulating in open-dumpsites and landfills in African-countries where they are recycled informally resulting in significant environmental and public-health concerns. Although, there is a plethora of studies on e-waste management and disposal, only a few-studies have focused on African-countries who are major recipients of e-waste. Moreover, despite the attempts to mitigate the problem of e-waste in African-countries, e-waste has remained a major-concern and there are currently very limited workable solutions. This study examines informal e-waste recycling, environmental pollution and the extent of environmental and health impacts in major countries of concern including Ghana, Nigeria, Egypt, Kenya and South Africa. The global e-waste Waste Atlas Report, 2020 identified these countries as major recipients of e-waste. To achieve the aims of this research, previous studies from 2005 to 2022 are collected from various databases and analyzed. Accordingly, this study focuses on environmental pollution and public-health impacts resulting from e-waste dumping and informal recycling practices, illegal transboundary shipment of e-waste to the selected countries, and the interventions of governments and international organizations in reducing the impact of e-waste pollution and informal recycling practices in Africa. Based on the outcomes of this study, practical approaches on the way-forward are recommended. The findings of this study contribute to a growing-body of research on informal e-waste recycling practices in Africa to document that individuals working within e-waste sites and residents in nearby communities are exposed to a number of toxic-substances, some at potentially concerning levels.

Evaluating the threshold limit value of acceptable exposure concentration for exposure to bioaerosols in a wastewater treatment plant: Reverse-quantitative microbial risk assessment and sensitivity analysis

Agitation operations produce numerous pathogenic bioaerosols in WWTPs¹. QMRA² can determine risks of persons exposed to these bioaerosols. However, QMRA framework cannot help stakeholders in immediately deciding whether a risk is intolerable. Thus, evaluating threshold of acceptable exposure concentration is an urgent issue but is still rarely addressed in WWTPs. This study analyzed TLV³ benchmarks of E. coli and S. aureus bioaerosols emitted from a WWTP by reverse-QMRA. Furthermore, variance of input parameters was clarified by sensitivity analysis. Results showed that, under conservative and optimistic estimates, TLV of technicians was 1.52-2.06 and 1.26-1.68 times as large as those of workers, respectively; wearing mask drive TLV up to 1-2 orders of magnitude; TLV of M⁴ was at most 1.33 and 1.31 times as large as that of RD⁵, respectively. For sensitivity analysis, removal fraction by equipping PPE enlarge TLV for effortlessly obtaining an acceptable assessment result; exposure time was dominant when without PPE excepting the scenario of technicians exposed to E. coli bioaerosol. This study helps establish threshold guidelines for bioaerosols in WWTPs and contribute innovative perspectives for stakeholders.

Dispersion characteristics of bioaerosols during treatment of rural solid waste in northwest China

In rural China, the release of bioaerosols containing pathogens from solid waste dumps poses a potential health risk to the local population. Here, we sampled bioaerosols from rural solid waste-treatment in four provinces of northwest China to investigate their emission and dispersion characteristics in order to provide a scientific basis for control and risk reduction of bioaerosols released from rural sanitation facilities. The airborne bioaerosol concentrations and particle size distributions were calculated using an Anderson six-stage airborne microbial sampler and counting with its internal Petri dish culture. High-throughput sequencing was used to characterize the microbial composition at different sampling sites and to explore possible influencing factors, while the health risk associated with exposure was estimated based on average daily dose-rate. The highest concentration point values of bacteria and fungi in bioaerosols near the solid waste were 63,617 ± 15,007 and 8044 ± 893 CFU/m³, respectively. Furthermore, the highest concentration point values of Enterobacteriaceae was 502 ± 35 CFU/m³. Most bioaerosols were coarse particles larger than 3.3 μm. Potentially pathogenic genera of winter-indicator species detected in the air were primarily Delftia, Rhodococcus and Aspergillus. The composition of solid waste and environmental conditions are important factors in determining the characteristics of bioaerosols. Local residents are exposed to bioaerosols mainly through inhalation. Children are at a particularly high risk of exposure through both inhalation and skin contact. The results of this study show that bioaerosols in the vicinity of rural solid waste dumps pose a health risk to the surrounding population. More suitable risk assessment criteria for rural areas should be established, and corresponding control and protection measures should be taken from three aspects: generation source and transmission pathway, as well as the recipient.

An overview of the environmental pollution and health effects associated with waste landfilling and open dumping

Landfilling is one of the most common waste management methods employed in all countries alike, irrespective of their developmental status. The most commonly used types of landfills are (a) municipal solid waste landfill, (b) industrial waste landfill, and (c) hazardous waste landfill. There is, also, an emerging landfill type called "green waste landfill" that is, occasionally, being used. Most landfills, including those discussed in this review article, are controlled and engineered establishments, wherein the waste ought to abide with certain regulations regarding their quality and quantity. However, illegal and uncontrolled "landfills" (mostly known as open dumpsites) are, unfortunately, prevalent in many developing countries. Due to the widespread use of landfilling, even as of today, it is imperative to examine any environmental- and/or health-related issues that have emerged. The present study seeks to determine the environmental pollution and health effects associated with waste landfilling by adopting a desk review design. It is revealed that landfilling is associated with various environmental pollution problems, namely, (a) underground water pollution due to the leaching of organic, inorganic, and various other substances of concern (SoC) contained in the waste, (b) air pollution due to suspension of particles, (c) odor pollution from the deposition of municipal solid waste (MSW), and (d) even marine pollution from any potential run-offs. Furthermore, health impacts may occur through the pollution of the underground water and the emissions of gases, leading to carcinogenic and non-carcinogenic effects of the exposed population living in their vicinity.

Metal Bioaccumulation, Cytogenetic and Clinico-Biochemical Alterations in Rattus norvegicus Exposed In Situ to a Municipal Solid Waste Landfill in Lagos, Nigeria

This study aimed at determining in animal model the health effects of in situ exposure to landfill chemicals. We evaluated metal concentrations in tissues and cytogenetic and clinico-biochemical effects in Wistar rats (Rattus norvegicus) exposed in situ at Olusosun landfill in Lagos, Nigeria. Male rats (n = 30/point) were exposed at three different points to ambient air and underground water (via drinking) at the landfill for 4-, 8-, 12-, 16-, 20- and 24-week periods. Rats concurrently sited at a residential area, 17.3 km from the landfill site served as control. There was significantly (p < 0.05) time-dependent: accumulation of lead, cadmium, chromium, copper and zinc in the liver and kidney and increase in body weight gain, in exposed rats compared to control. There was significant induction of micronuclei and cytotoxicity (reduced PCE/NCE ratios) in exposed rats. Haematological parameters (RBC, PCV, Hb and WBC) and serum biomarkers of hepato-renal damage [aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) activities; creatinine and urea levels] revealed significant increases. There was significant increase in hepatic levels of reduced glutathione, malondialdehyde, catalase activities, and decrease in superoxide dismutase, at all periods. Chromium and copper concentrations in the liver and kidney revealed significant positive correlations with either one or more of AST, ALT, LDH and urea. Significant metal concentrations in the underground water and tissues suggest that heavy metals are responsible for the observed alterations, and this may have been via oxidative stress. These findings suggest potential health risk due to occupational and residential exposure to landfill pollutants.

Microbial aerosol particles in four seasons of sanitary landfill site: Molecular approaches, traceability and risk assessment

Landfill sites are regarded as prominent sources of bioaerosols for the surrounding atmosphere. The present study focused on the emission of airborne bacteria and fungi in four seasons of a sanitary landfill site. The main species found in bioaerosols were assayed using high-throughput sequencing. The SourceTracker method was utilized to identify the sources of the bioaerosols present at the boundary of the landfill site. Furthermore, the health consequences of the exposure to bioaerosols were evaluated based on the average daily dose rates. Results showed that the concentrations of airborne bacteria in the operation area (OPA) and the leakage treatment area (LTA) were in the range of (4684 ± 477)-(10883 ± 1395) CFU/m³ and (3179 ± 453)-(9051 ± 738) CFU/m³, respectively. The average emission levels of fungal aerosols were 4026 CFU/m³ for OPA and 1295 CFU/m³ for LTA. The landfill site received the maximum bioaerosol load during summer and the minimum during winter. Approximately 41.39%- 86.24% of the airborne bacteria had a particle size of 1.1 to 4.7 µm, whereas 48.27%- 66.45% of the airborne fungi had a particle size of more than 4.7 µm. Bacillus sp., Brevibacillus sp., and Paenibacillus sp. were abundant in the bacterial population, whereas Penicillium sp. and Aspergillus sp. dominated the fungal population. Bioaerosols released from the working area and treatment of leachate were the two main sources that emerged in the surrounding air of the landfill site boundary. The exposure risks during summer and autumn were higher than those in spring and winter.

Quantitative Microbial Risk Assessment (QMRA) of Workers Exposure to Bioaerosols at MSW Open Dumpsites

The bioaerosol exposure data from the study by Akpeimeh, Fletcher, and Evans (2019) was used to compute the risk of infection from the exposure of dumpsite workers to Aspergillus fumigatus and Escherichia coli O157:H7. A stochastic (Markov Chain) model was used to model the transport of the inhaled dose though the human respiratory system and then integrated into the beta-Poisson dose-response model to estimate workers risks of respiratory and gastrointestinal (GI) infection. The infection risk was computed based on workers exposure to E. coli O157:H7 at 10-50% pathogen ingestion rate and pathogen-indicator ratio (P:I) of 1:10³ and 1:10⁴ , while exposure to A. fumigatus was based solely on the average initial exposure dose. The results showed that after 11 hours of exposure, workers engaged in scavenging, waste sorting, and site monitoring were at risk of respiratory and GI infection in the magnitude of 10^-1 . However, the risk estimates associated with specific areas of the dumpsite showed that, the risk of GI infection at the active area ranged between 3.23 × 10^-3 -1.56 × 10^-2 and 3.25 × 10^-4 -1.62 × 10^-3 ; dormant area 2.06 × 10^-3 -1.01 × 10^-2 and 2.09 × 10^-4 -1.04 × 10^-3 ; entrance 1.85 × 10^-3 -9.09 × 10^-3 and 1.87 × 10^-4 -9.27 × 10^-4 ; boundary 1.82 × 10^-3 -8.82 × 10^-3 and 2.09 × 10^-4 -8.94 × 10^-4 for P:I = 1:10³ and 1:10⁴ respectively, while the risk of respiratory infection risks were in the magnitude of 10^-1 for all four locations. The estimated risk of workers developing respiratory and gastrointestinal infections were high for all activities assessed at the dumpsite.

Contributions of meat waste decomposition to the abundance and diversity of pathogens and antibiotic-resistance genes in the atmosphere

Airborne transmission of antibiotic-resistance genes (ARGs) in landfill and acquisition of antibiotic resistance by pathogenic bacteria are posing potential threat to human and environmental health. However, little is known about contribution of waste decomposition to airborne ARGs and pathogens during landfilling of household waste. Herein, the dynamic changes of microbial communities and ARGs were comparatively investigated in leachate and bioaerosol during the decomposition of chicken, fish, and pork wastes. Results found that chicken and pork decomposition could result in emitting high abundance of bioaerosol and pathogen, while fish fermentation will lead to high airborne microbial activity. The main pathogens were Bacilli, Burkholderia-Paraburkholderia and Mycobacterium in bioaerosols, but were Wohlfahrtiimonas, Peptoniphilus and Fusobacterium in leachate, suggesting that the ability of aerosolization of bacteria in leachate was independent of their abundance and diversity. Whereas, diversity and relative abundance of ARGs in leachate were significantly higher than bioaerosol. Moreover, the relative abundance of ARGs in leachate and bioaerosols was not completely relevant. The changes of pathogenic community contributed significantly to the prevalence of ARGs in bioaerosol and leachate. The results will define the contribution of household waste decomposition to airborne pathogen and ARG distribution and provide foundation for airborne bacterial exposure risk and control in landfill.

Pollution threat to water and soil quality by dumpsites and non-sanitary landfills in Brazil: A review

This work presents an overview of environmental studies performed in areas affected by dumpsites and non-sanitary landfills in Brazil, focusing on physicochemical analysis of surface water, groundwater, and soils, as well as geophysical surveys. The objective was to identify the main contaminants found in these areas and to assess their environmental impact, guiding possible intervention measures, indicating the priority areas, and showing whether post-closure activities are mandatory. The results should support governmental actions, especially considering the recent approval of Brazil's new sanitation framework. The present review assessed 162 publications, which described 104 different municipal solid waste (MSW) disposal sites. The physicochemical parameters of analyzed surface water, groundwater, and soil samples were above Brazilian legislation levels in 74%, 70%, and 24% of the studies, respectively. The parameters more frequently above permissible levels were coliforms, biochemical oxygen demand, dissolved oxygen, and phosphorus for surface water; lead, coliforms, and iron for groundwater; copper, cadmium, lead, and zinc for soil. The results indicated that Brazilian dumpsites are causing negative impacts in surrounding soils and water resources, posing ecological and public health risks that persist even after the site's closure. Considering that this study provides only a reduced scenario, the dimension of this environmental problem in Brazil is noteworthy. Therefore, it is suggested that not only inadequate disposal is prohibited, but also efficient enforcement methods are adopted and aftercare is appropriately regulated in the country, making it obligatory to establish monitoring plans and implement mitigation techniques to avoid abandoning potentially contaminated areas.

Characteristics and health effects of potentially pathogenic bacterial aerosols from a municipal solid waste landfill site in Hamadan, Iran

The aim of this study was to evaluate the potential pathogenic bacterial aerosols produced from the municipal solid waste landfill site and its health risk assessment in the Hamadan city at west of Iran. In this study, air samples were collected every month during spring and summer at six locations including the active zone, leachate collection pond, infectious waste landfill, upwind, closure landfill, and downwind using the Andersen impactor. Spatial and seasonal variations of the potential pathogenic bacterial aerosols were detected. Also, Health risk associated were estimated based on the average daily dose rates (ADD) of exposure by inhalation. The mean concentration of potentially pathogenic bacterial aerosols were 468.7 ± 140 CFU m^- 3 1108.5 ± 136.9 CFU m^- 3 detected in the active zone in spring and summer, respectively. Also, there was a significant relationship between meteorological parameters and bacterial concentration (p < 0.05). The predominant potential pathogenic bacterial identified in the spring were Proteus mirabilis, Streptococcus sp., and Pseudomonas sp., while in summer were Pseudomonas sp., Staphylococcus aureus, and Escherichia coli. The hazard quotient (HQ) in both seasons were less of 1. Bacteria were spread throughout the landfill space, but their maximum density was observed around the active zone and leachate collection pond. This study highlights the importance of exposure to potential pathogenic bacterial aerosols in the summer and its adverse effects, especially in the MSW landfill site active zone. Finally, controlled exposure can reduce the health hazard caused by the potential pathogenic bacterial aerosols.

Emission characteristics of bioaerosol and quantitative microbiological risk assessment for equipping individuals with various personal protective equipment in a WWTP

Wastewater treatment plants (WWTPs) are a nonnegligible source of bioaerosols that can pose health risks to workers and nearby residents. Thus, this study systematically investigated the emission characteristics of the size distribution and concentration of Staphylococcus aureus bioaerosol in a WWTP. Then, the research focused on the quantitative microbiological risk assessment (QMRA) of workers and nearby residents for equipping them with various grades personal protective equipment (PPE). Results showed that the peak proportion of the size distributions of bioaerosol particles in the three sources all obtained a size range between 3.3 and 4.7 μm. In the residential building, the peak proportion was larger (>7.0 μm). Referring to the three sources, the average bioaerosol concentrations were in the following sequence: inverted umbrella aerator tank > residual sludge storage yard > microporous aerator tank. The health risks of residents were generally 1-2 orders of magnitude higher than the other two exposure scenarios and were clearly beyond the benchmarks. Meanwhile, the health risks of the field engineer were usually lower than those of the staff at the residual sludge storage yard. In general, equipping workers and residents with PPE could at least decrease the health risks by one order of magnitude, and higher-grade PPE could appropriately promote the reduction of health risks. This research systematically delivered a series of novel data about the emission characteristics of Staphylococcus aureus bioaerosol in a WWTP. It advanced the understanding of the quantitative health risks of equipping individuals with various PPE.

Bioaerosols in the landfill environment: an overview of microbial diversity and potential health hazards

Landfilling is one of the indispensable parts of solid waste management in various countries. Solid waste disposed of in landfill sites provides nutrients for the proliferation of pathogenic microbes which are aerosolized into the atmosphere due to the local meteorology and various waste disposal activities. Bioaerosols released from landfill sites can create health issues for employees and adjoining public. The present study offers an overview of the microbial diversity reported in the air samples collected from various landfill sites worldwide. This paper also discusses other aspects, including effect of meteorological conditions on the bioaerosol concentrations, sampling techniques, bioaerosol exposure and potential health impacts. Analysis of literature concluded that landfill air is dominated by microbial dust or various pathogenic microbes like Enterobacteriaceae, Staphylococcus aureus, Clostridium perfringens, Acinetobacter calcoaceticus and Aspergillus fumigatus. The bioaerosols present in the landfill environment are of respirable sizes and can penetrate deep into lower respiratory systems and trigger respiratory symptoms and chronic pulmonary diseases. Most studies reported higher bioaerosol concentrations in spring and summer as higher temperature and relative humidity provide a favourable environment for survival and multiplication of microbes. Landfill workers involved in solid waste disposal activities are at the highest risk of exposure to these bioaerosols due to their proximity to solid waste and as they practise minimum personal safety and hygiene measures during working hours. Workers are recommended to use personal protective equipment and practise hygiene to reduce the impact of occupational exposure to bioaerosols.

The Integration of Recycling Cooperatives in the Formal Management of Municipal Solid Waste as a Strategy for the Circular Economy—The Case of Londrina, Brazil

In many developing countries, the informal recycling sector is responsible for reducing the amount of waste in landfills and supplying the needs of recycling industries. In the context of municipal solid waste (MSW) management, considering that developing countries aim to implement circular economy (CE) actions, it is essential to ensure the inclusion of waste pickers (catadores) in an adapted CE structure. This study analyzes the integration of recycling cooperatives in the formal management of municipal solid waste with recyclable potential (MSWRP) of a medium-sized municipality in Brazil, with the objective of ascertaining the contributions of cooperatives in an adapted CE structure and, at the same time, identifying a cooperative that can be used as a benchmarking option for other cooperatives, especially in relation to their organizational and operational practices. The results indicate that from this integration, cooperatives have legal responsibility in the management of MSWRP, resulting in the professionalization of its members and increasing their productivity. The results also revealed that the implementation of the CE in developing countries is, in a sense, conditioned to the performance of the informal sector in the recycling chain and, in addition, that the inclusion of cooperatives in the formal sector of MSWRP management can improve the rates of a municipality.

Exposure to endotoxins and respiratory health in composting facilities

The impact of bioaerosols in municipal solid waste management is nowadays identified as a growing health concern worldwide. In this study, exposure to endotoxin in composting facilities and its association with lung function and clinical symptoms was investigated in Tehran municipal solid waste management complex (Aradkooh) as one of the largest solid waste management facilities in the Middle East. Airborne endotoxins were collected between June and July 2019 and the concentrations were determined by Limulus Amebocyte Lysate (LAL) method. Healthy workers with no history of respiratory disease were recruited and data on clinical symptoms (cough, phlegm, wheezing, dyspnea, fatigue, headache, eye irritation, runny nose, runny eyes, and sore throat) was obtained by the modified American Thoracic Society questionnaire, and spirometric measurement was performed by an expert. The binary logistic regression test was used and adjusted for confounding variables. The results didn't show any difference in lung function parameters (FEV₁, FVC, FEV₁/FVC, PEF, FEF_25-75%), and most of the respiratory symptoms despite a relatively high difference in the concentration of endotoxin observed in air samples of different locations. Only the increased risk of cough (OR 10.5, 95% CI: 2.4 to 44.8 in the moderately exposed group and 7.8, 95% CI: 1.6 to 39.1 in highly exposed ones), fatigue (OR 3.7, 95% CI: 1.2 to 11.7), and headache (OR 6.02, 95% CI: 1.4 to 24.5) were found in the exposed groups compared to controls after adjusting for age, active and passive smoking. However, findings of the study might be underestimated due to some issues including healthy worker effect, intra and intersubject variability, and self-reporting bias, thereby the results should be interpreted with caution. Although we did not find any relationship, due to the high concentrations of endotoxins observed in some sites, it is recommended to consider some possible prevention measures such as using personal protective equipment to reduce the exposure of workers at an acceptable level.

Microbial Air Quality in Neighborhoods near Landfill Sites: Implications for Public Health

Air pollution has been a major challenge worldwide particularly in the developing world. Improper waste disposal and management may result in microbial air pollution. In advanced countries, landfill sites are far from neighborhoods; however, the opposite is observed for landfill sites in the developing world. In Accra, some landfill sites are 100 meters from neighborhoods. The aim of this study was to assess the microbial air quality and associated environmental health hazards of landfill sites in selected districts in the Greater Accra Region of Ghana. A random sampling method was employed to select sampling sites across the dry and wet seasons from landfills and their corresponding neighborhoods. Results obtained showed a higher total count (CFU/m³) of bacteria and fungi in the air at the landfill sites than neighborhoods. Statistically significant variation (p < 0.05) in bacterial and fungal concentrations over two seasons was found for both landfills and neighborhoods. However, bacterial concentrations were significantly higher than fungal concentrations (p < 0.05) across seasons for all locations. Staphylococcus epidermidis was the highest (15.6 %) occurring microbe at both landfill sites and neighborhoods. This was followed by Staphylococcus aureus (12.7%). Other bacteria and fungi of public health importance such as Pseudomonas aeruginosa, Escherichia coli, Aspergillus flavus, and Aspergillus niger were also isolated from the study sites, above the WHO recommended levels. In conclusion, the landfill waste disposal and its close proximity to neighborhoods as observed in this study pose a potential environmental health risk, with dire implications for public health and safety. The government must enact and implement policies to regulate waste management and to ensure public safety.

Persistent impacts of an abandoned non-sanitary landfill in its surroundings

The inadequate disposal of solid waste, a common practice in developing countries, can represent an important pollution source since the closure of these deposits typically does not include the adoption of monitoring, isolation, or remediation techniques. Even so, several disposal areas are abandoned, without performing long-term monitoring in order to evaluate the depletion of contaminants' concentrations. This research aimed at comparing current and historical physicochemical data of water resources surrounding a non-sanitary landfill situated in a Guarani Aquifer recharge zone. The primary objective was to recognize whether significant changes in contaminants concentrations occurred, as well as if the area still poses a significant threat to the environment, 20 years after ending disposing activities. Samples from eight monitoring wells and three surface water points (upstream and downstream to the deposit) were evaluated in the periods of 1996-1997 and 2016-2019. The parameters pH, electrical conductivity (EC), alkalinity, chemical oxygen demand (COD), oxidation-reduction potential (ORP), chloride, nitrate, iron, manganese, calcium, and magnesium were investigated. Contamination has been detected in the landfill surroundings since the ending of the waste disposal (1996-1997), even though its intensity reduced within short distances from the waste mass. Nevertheless, no statistical variation occurred in 20 years' time considering COD, chloride, calcium, magnesium, and ORP. Moreover, increases of EC, pH, alkalinity, iron, and manganese concentrations were observed for the years of 2016-2019. The results indicate that the evaluated contaminants do not suffer depletion in the surroundings of non-sanitary landfills in sandy aquifers, considering a time span of 20 years. This study also suggests that those areas need to be adequately remediated to permit other future land uses.

Ambient bioaerosol distribution and associated health risks at a high traffic density junction at Dehradun city, India

Traffic junctions are one of the crowded places where commuters are at high risk of developing respiratory infections, due to their greater exposure to airborne and human transmitted microbial pathogens. An airborne bioaerosol assessment study was carried out at a high traffic density junction focusing on their concentration, contribution in respirable particulate matter (PM), and factors influencing the distribution and microbial diversity. Andersen six-stage viable cascade impactor and a wide-range aerosol spectrometer were used for microbial and particulate matter measurements, respectively. Statistical analysis was conducted to evaluate the relationship between bioaerosol concentration, vehicular count, PM concentration, and meteorological parameters. The mean bacteria concentration (1962.95 ± 651.85 CFU/m3) was significantly different than fungi (1118.95 ± 428.34 CFU/m3) (p < 0.05). The temporal distribution showed maximum concentration for bacteria and fungi during monsoon and postmonsoon seasons, respectively. In terms of bioaerosol loading, a considerable fraction of fungi (3.25%) and bacteria (5.65%) contributed to the total airborne PM. Most abundant bioaerosols were Aspergillus (27.58%), Penicillium (23%), and Cladosporium (14.05%) (fungi), and Micrococcus (25.73%), Staphylococcus (17.98%), and Bacillus (13.8%) (bacteria). Traffic-induced roadside soil resuspension and microbial aerosolizations from the human body were identified as the chief sources of bioaerosol emissions. The risk of lower respiratory tract infections caused by anthroponotic (human transmitted) transfer of bacterial pathogens is very high. The results of the study can be used to trace sources of microbial mediated communicable diseases, and to recommend appropriate safety measures to avoid pathogenic bioaerosol exposure.