Exposure to aerosolized bacteria and fungi among collectors of commercial, mixed residential, recyclable and compostable waste

Advances in understanding bioaerosol release characteristics and potential hazards during aerobic composting

Bioaerosol emissions and their associated risks are attracting increasing attention. Bioaerosols are generated during the pretreatment, fermentation, and screening of mature compost when processing various types of solid waste at composting plants (e.g., municipal sludge and animal manure). In this review, we summarize research into bioaerosols at different types of composting plants by focusing on the methods used for sampling bioaerosols, stages when emissions potentially occur, major components of bioaerosols, survival and diffusion factors, and possible control strategies. The six-stage Andersen impactor is the main method used for sampling bioaerosols in composting plants. In addition, different composting management methods mainly affect bioaerosol emissions from composting plants. Studies of the components of bioaerosols produced by composting plants mainly focused on bacteria and fungi, whereas few considered others such as endotoxin. The survival and diffusion of bioaerosols are influenced by seasonal effects due to changes in environmental factors, such as temperature and relative humidity. Finally, three potential strategies have been proposed for controlling bioaerosols in composting plants. Improved policies are required for regulating bioaerosol emissions, as well as bioaerosol concentration diffusion models and measures to protect human health.

Assessment of waste workers occupational risk to microbial agents and cytotoxic effects of mixed contaminants present in the air of waste truck cabin and ventilation filters

Workers in the waste-processing industry are potentially exposed to high concentrations of biological contaminants, leading to respiratory and digestive problems and skin irritations. However, few data on the exposure of waste collection truck (WCT) drivers are available. The goal was to document the microbial risk of the waste collection truck (WCT) workers while in the vehicle cab. Long-period sampling using the truck air filters (CAF) and short time ambient air sampling in the cab were used. The potential release of microbial particles from CAFs was also investigated since it could contribute to the microbial load of the cabin air. A combination of analytical methods also helped assess the complex mixture of the biological agents. Aspergillus sections Fumigati and Flavi, E. coli, Enterobacter spp. and Legionella spp. were detected in the CAF of trucks collecting three types of waste. The highest levels of bacteria and fungi were found in the CAF from organic WCT. The highest endotoxin concentrations in CAF were 300 EU/cm2. Most of the CAF showed cytotoxic effects on both lung cells and hepatocytes. Only one mycotoxin was detected in a CAF. The maximal concentrations in the ambient WCT air varied according to the type of waste collected. The highest proportion (84%) of the air samples without cytotoxic effects on the lungs cells was for the recyclable material WCTs. The results revealed the potential microbial risk to workers from a complex mixture of bio-contaminants in the cabs of vehicles collecting all types of waste. The sustained cytotoxic effect indicates the potential adverse health-related impact of mixed contaminants (biological and non-biological) for the workers. Overall, this study highlights the benefits of using complementary sampling strategy and combined analytical methods for a the assessment of the microbial risk in work environments and the need to implement protective measures for the workers.Implications: Exposure to microbial agents is a well-known occupational hazard in the waste management sector. No previous study had evaluated the cytotoxicity of ambient air and ventilation filters to document worker exposure to a combination of contaminants during waste collection. This research confirms the usefulness of ventilation filters for long-term characterization of exposure to infectious agents, azole-resistant fungi, coliform bacteria and mycotoxin. Overall, this study highlights the importance of using several sampling and analysis methods for a comprehensive assessment of microbial risk in work environments, as well as the need to implement appropriate protective measures for collection workers.

Global systematic review of occupational health and safety outcomes among sanitation and hygiene workers

Introduction

Sanitary workers are exposed to a variety of occupational hazards in a variety of working environments, which can result in occupational-related outcomes. As a result, the goal of this review was to identify occupational health and safety outcomes among sanitary workers worldwide.

Methods

PRISMA was used as flow diagram and PICOS was used review questions. The studies published in English were searched from databases and others methods ranging from 2000 to 2022. Boolean logic (AND, OR), MeSH, and keywords used: (Occupation *OR Job *OR Work) AND (Occupational related respiratory Symptoms *OR Disease) AND [Solid waste collectors (SWCs) *OR Street sweepers (SS) *OR Sewage workers and waste treatment (STWs)] AND (Countries).

Results

A total of 228 studies were identified from 23 countries across the world. Studies were found via PubMed (n = 40), Medline (n = 25), Embase (n = 11) and Global Health (n = 66) and Google scholar (n = 63) and from previous (n = 23). From 8,962 of eligible sanitary workers, about 4,742 (54%), 1714 (19%) and 1,441 (16%) were sewage, sweepers and solid waste workers, respectively. A total study (n = 51) were eligible for occupational health and safety outcomes. Of these, respiratory problems accounted 27 (52%) and Gastroenteritis 14 (27%).

Conclusion

Despite a large number of studies to date provides sanitary employees all over the world face occupational-related risks, hence more research is needed to enhance and quantify illness burden among sanitary workers.

Health symptoms, inflammation, and bioaerosol exposure in workers at biowaste pretreatment plants

Biowaste pretreatment plants have been built within the last years in Denmark in order to recycle pre-sorted biowaste from houses, restaurants, and industry. We investigated the association between exposure and health at six biowaste pretreatment plants (visited twice) across Denmark. We measured the personal bioaerosol exposure, took blood samples, and administered a questionnaire. Thirty-one persons participated, 17 of them twice, resulting in 45 bioaerosol samples, 40 blood samples, and questionnaire answers from 21 persons. We measured exposure to bacteria, fungi, dust, and endotoxin, the total inflammatory potential of the exposures, and serum levels of the inflammatory markers serum amyloid A (SAA), high sensitivity C-reactive protein (hsCRP), and human club cell protein (CC16). Higher exposures to fungi and endotoxin were found for workers with tasks inside the production area compared to workers with main tasks in the office area. A positive association was found between the concentration of anaerobic bacteria and hsCRP and SAA, whereas bacteria and endotoxin were inversely associated with hsCRP and SAA. A positive association between hsCRP and the fungal species Penicillium digitatum and P. camemberti were found, whereas an inverse association between hsCRP and Aspergillus niger and P. italicum were found. Staff with tasks inside the production area reported more symptoms of the nose than those working in the office area. To conclude, our results indicate that workers with tasks inside the production area are exposed to elevated levels of bioaerosols, and that this may affect workers' health negatively.

Divergent TLR2 and TLR4 Activation by Fungal Spores and Species Diversity in Dust from Waste Sorting Plants

This manuscript presents the results of an exploratory study on the relationships between NF-κB response through Toll-like receptor (TLR) activation by dust characterized by fungal spore concentrations and species diversity. Personal total dust samples were collected from Norwegian waste sorting plants and then characterized for fungal spores and fungal species diversity, as well as for other bioaerosol components, including endotoxins and actinobacteria. The ability of the dust to induce an NF-κB response by activating TLR2 and TLR4 in vitro was evaluated, as well as the relationship between such responses and quantifiable bioaerosol components. The average concentrations of bioaerosols were 7.23 mg total dust m^-3, 4.49 × 10⁵ fungal spores m^-3, 814 endotoxin units m^-3, and 0.6 × 10⁵ actinobacteria m^-3. The mean diversity measurements were 326, 0.59, and 3.39 for fungal richness, evenness, and Shannon index, respectively. Overall, fungal operational taxonomic units (OTUs) belonging to the Ascomycota phylum were most abundant (55%), followed by Basidiomycota (33%) and Mucoromycota (3%). All samples induced significant NF-κB responses through TLR2 and TLR4 activation. While fungal spore levels were positively associated with TLR2 and TLR4 activation, there was a trend that fungal species richness was negatively associated with the activation of these receptors. This observation supports the existence of divergent immunological response relationships between TLR activation and fungal spore levels on one hand and between TLR activation and fungal species diversity on the other. Such relationships seem to be described for the first time for dust from waste facilities. IMPORTANCE This manuscript presents results on multifactorial characterization of bioaerosol exposure in Norwegian waste sorting plants and the potential of such airborne dust to induce NF-κB reactions through TLR2 and TLR4 activations in an in vitro reporter cell model system. Our data revealed that increasing fungal spore levels in the dust is associated with increased activation of TLR2 and TLR4, whereas increasing fungal OTU richness is associated with decreasing activation of these receptors. The NF-κB-induced responses by the collected dust represent, therefore, effective measures of potential key immunological effects induced by a complex mixture of hazardous components, including characterized factors such as endotoxins, fungal spores, bacteria, and many other uncharacterized components. The key immunological events reported here are suggested as holistic alternatives to today's bioaerosol exposure characterization approaches for epidemiological studies in the future.

Association between urban garbage exposure and allergic diseases among sanitation practitioners: A cross-sectional study

Background

The prevalence of allergic diseases has increased significantly in China over the last few decades, and there have been very few reports of allergic diseases in certain occupational specialties, with almost no reports among sanitation workers.

Objective

Our objective was to investigate the prevalence of allergic diseases and the prevalence of common allergen sensitization in the population engaged in sanitation, and to try to answer the connection between urban garbage waste exposure and the development of allergic diseases.

Methods

We conducted a cross-sectional survey of people working in sanitation-related jobs in Liwan District, Guangzhou, China. A total of 893 people completed the questionnaire for this study, and 500 of them were further screened and tested for allergens specific IgE and IgG4. Combining the questionnaire and test results, we investigated the incidence of allergy disorders and patterns of sensitization to allergens in this community, and evaluated the presence of occupational-related risk factors in this particular population.

Results

Of the 893 sanitation workers, 166 (18.59%) self-reported allergic diseases, predominantly suffering from allergic rhinitis (AR) (n = 98, 10.97%), followed by drug allergy (n = 31, 3.47%), atopic dermatitis (n = 27, 3.02%), food allergy (n = 21, 2.35%), and asthma (n = 9, 1.00%), in that order. In addition to dust mites (32.20%), which had the highest sensitization rate, the subject population had relatively high sensitization rates to ragweed (7.00%) and moulds mixture (8.20%) when compared with the rates of sensitization to moulds and ragweed in the general population; the top 3 sIgG4 positivity rates were egg (50.00%), milk (10.20%), and soybean (9.40%). The prevalence of self-reported AR was higher in office managers (the control group) than in cleaning staff (the exposed group), but there was no difference in sIgE positivity for serum allergens between the 2 groups. The chance of having AR may increase with management positions (crude OR 2.20, 95% CI 1.38-3.50), P = 0.001).

Conclusion

This is the first study to investigate the prevalence of allergy illnesses in the sanitation workforce in mainland China. We identified a community of real sanitation workers with high ragweed and mycobacterial sensitization rates. Urban cleaning may be protective factor against AR at the symptom level, but the serological results did not show this to be the case.

Distribution characteristics and potential risks of bacterial aerosol in waste transfer station

The waste transfer station (WTS) is an important link in the transfer of municipal solid waste (MSW) between the community and disposal terminals. While WTSs facilitate waste collection in communities, odorous gases and bioaerosols can escape from them, thereby negatively affecting their surroundings. In this study, the concentration, particle size distribution, pathogen population, and health risks of bioaerosols were analyzed at different locations in a transfer station. The results showed that the highest viable bacterial aerosol concentration was 10,353 ± 3701 CFU/m³, which was at 5 m from the disposal site. Fifty-three bacterial species, including pathogens, were detected. Of these, 39 were human pathogenic bacteria directly originating from the WTS. Furthermore, health risk assessments indicated unacceptable levels of non-carcinogenic risk for operational workers caused by bacterial aerosols of the WTS work area. In addition, bacterial aerosols may pose a severe health risk to children within a 15 m area of the WTS. The results of this study provide a scientific basis to control and reduce the risk associated with bioaerosol exposure in solid WTSs.

Microbial contamination and metabolite exposure assessment during waste and recyclable material collection

Waste workers are exposed to bioaerosols when handling, lifting and dumping garbage. Bioaerosol exposure has been linked to health problems such as asthma, airway irritant symptoms, infectious, gastrointestinal and skin diseases, and cancer. Our objective was to characterize the exposure of urban collectors and drivers to inhalable bioaerosols and to measured the cytotoxic effect of air samples in order to evaluate their health risk. Personal and ambient air sampling were conducted during the summer of 2019. Workers from 12 waste trucks collecting recyclables, organic waste or compost were evaluated. Bacteria and fungi were cultured, molecular biology methods were used to detect microbial indicators, cytotoxic assays were performed and endotoxins and mycotoxins were quantified. Domestic waste collectors were exposed to concentrations of bacteria and endotoxins above the recommended limits, and Aspergillus section Fumigati was detected at critical concentrations in their breathing zones. Cytotoxic effects were observed in many samples, demonstrating the potential health risk for these workers. This study establishes evidence that waste workers are exposed to microbial health risks during collection. It also demonstrates the relevance of cytotoxic assays in documenting the general toxic risk found in air samples. Our results also suggest that exposures differ depending on the type of waste, job title and discharge/unloading locations.

Characteristics and health effects of particulate matter emitted from a waste sorting plant

Solid waste components can be recycled in waste paper and cardboard sorting plants (WPCSP) through a multistep process. This work collected 15 samples every six days from each of the 9 points selected to study the processes taking place in a WPCSP (135 particulate matter samples total). Examining the concentration and size fraction of particulate matter (i.e., PM₁, PM_2.5 and PM₁₀) in WPCSP is an essential issue to notify policy makers about the health impacts on exposed workers. The major activities for increasing of the concentration of PM in various processing units in the WPCSP, especially in hand-picking routes I and II were related to manual dismantling, mechanical grinding, mechanical agitation, and separation and movement of waste. The results of this work showed that a negative correlation between temperature and particulate matter size followed the order PM₁₀ > PM_2.5 > PM₁. Exposure to PM_2.5 and PM₁₀ in the WPCSP lead to possible risk (HI = 5.561 and LTCRs = 3.41 × 10^-6 to 9.43 × 10^-5 for PM_2.5 and HI = 7.454 for PM₁₀). The exposure duration and the previous concentrations had the most effect on the ILCRs and HQs for PM_2.5 and PM₁₀ in all sampling sites. Hence, because WPCSP are infected indoor environments (I/O ratio > 1), the use of control methods such as isolation of units, misting systems, blower systems equipped with bag houses, protective equipment, a mechanical ventilation system, and additional natural ventilation can reduce the amount of suspended PM, enhance worker safety, and increase the recycling rate.

Characteristics and assessing biological risks of airborne bacteria in waste sorting plant

Examining the concentration and types of airborne bacteria in waste paper and cardboard sorting plants (WPCSP) is an urgent matter to inform policy makers about the health impacts on exposed workers. Herein, we collected 20 samples at 9 points of a WPCSP every 6 winter days, and found that the most abundant airborne bacteria were positively and negatively correlated to relative humidity and temperature, respectively. The most abundant airborne bacteria (in units of CFU m^-3) were: Staphylococcus sp. (72.4) > Micrococcus sp. (52.2) > Bacillus sp. (30.3) > Enterococcus sp. (24.0) > Serratia marcescens (20.1) > E. coli (19.1) > Pseudomonas sp. (16.0) > Nocardia sp. (1.9). The lifetime average daily dose (LADD) for the inhalation and dermal routes for the intake of airborne bacteria ranged from 3.7 × 10^-3 ≤ LADD_Inhalation ≤ 2.07 × 10¹ CFU (kg d)^-1 and 4.75 × 10^-6 ≤ LADD_Dermal ≤ 1.64 × 10^-5 CFU (kg d)^-1, respectively. Based on a sensitivity analysis (SA), the concentration of airborne bacteria (C) and the exposure duration (ED) had the most effect on the LADD_Inhalation and LADD_Dermal for all sampling locations. Although the Hazard Quotient of airborne bacteria was HQ < 1, an acceptable level, the indoor/outdoor ratio (1.5 ≤ I/O ≤ 6.6) of airborne bacteria typically exceeded the threshold value (I/O > 2), indicating worker's exposure to an infected environment. Therefore, in the absence of sufficient natural ventilation the indoor ambient conditions of the WPCSP studied should be controlled by supplying mechanical ventilation.

Screening for respiratory morbidities and obstructive lung function among municipal waste handlers in Puducherry: A community-based cross-sectional study

Background:

Waste management is a societal problem because of its environmental impact and public health implications. Solid waste handlers have a high incidence of occupational health issues, with respiratory morbidities being the most common. Aim: To assess the prevalence of respiratory morbidities, obstructive lung pattern and its associated factors among municipal solid waste management workers in Puducherry.

Materials and Methods:

This community-based cross-sectional study was carried out in May and June 2018 among 264 solid waste management workers selected by simple random sampling. They underwent a semi-structured interview schedule capturing their sociodemographic characteristics, work profile, presence of respiratory symptoms, and morbidities followed by lung function tests using a portable spirometer. The data was entered using Epidata entry client and analyzed using SPSS (v16).

Results:

The mean age of the workers was 47.1 (±8.87) years. The majority were females (85.6%), working as waste collectors (86%) on day duty (73.5%). More than two in five workers had either respiratory morbidity (42.8%) or obstructive lung pattern (44%). Higher age, occupation as waste collector, night shift duty, not using face mask on duty, and not receiving training on waste handling were the factors significantly associated with the respiratory morbidities and obstructive lung function.

Conclusion:

The prevalence of respiratory morbidities and obstructive lung disease were high among municipal solid waste handlers. Measures are needed to improve the work environment of waste handlers by ensuring the availability of protective gears and adequate training on work handling based on ergonomic principles.

Simultaneous annihilation of microorganisms and volatile organic compounds from municipal solid waste storage rooms with slightly acidic electrolyzed water

Great deal pathogenic bacteria and malodorous gases are hidden in municipal solid waste (MSW), which poses excellent environmental sanitation risks for sanitation workers and residents, and preventive measures should be implemented. In this study, the simultaneous annihilation of microorganisms and volatile organic compounds (VOCs) with slightly acidic electrolyzed water (SAEW) was investigated in an MSW storage room of a residential community in Shanghai, China. The microbial population of airborne, surfaces and handles of waste bins, hands of sanitation workers and the main components of VOCs were measured. The results indicated that the bacterial reduction efficiencies of SAEW with an available chlorine concentration (ACC) of 50-100 mg/L on surfaces and handles of waste bins and sanitation workers' hands were 22.7%-84.1%. Also, SAEW effectively reduced the average population of airborne bacteria and fungi by 358 and 378 colony-forming units (CFU)/m³ and decreased the detection rates of coliforms by 14.2%-51.9%. The concentrations of most VOCs were reduced by 21.4%-88.3% after spraying SAEW. And the accumulated values of carcinogenic and noncarcinogenic risks also tended to decrease with spraying SAEW. These findings imply that SAEW has significant application potential to control environmental sanitation risks in MSW storage rooms.

Review of biological risks associated with the collection of municipal wastes

In many countries, the management of household waste has recently changed with an increased focus upon waste sorting resulting in lower collection frequency for some waste fractions. A consequence of this is the potential for increased growth of microorganisms in the waste before collection, which can lead to an increased exposure via inhalation for waste collection workers. Through a review of the literature, we aimed to evaluate risks caused by waste collecting workers' exposure to bioaerosols and to illuminate potential measures to reduce the exposure. Across countries and waste types, median exposure to fungi, bacteria, and endotoxin were typically around 10⁴ colony forming units (cfu)/m³, 10⁴ cfu/m³, and 10 EU/m³, respectively. However, some studies found 10-20+ times higher or lower median exposure levels. It was not clear how different types of waste influence the occupational exposure levels. Factors such as high loading, ventilation in and cleaning of drivers' cabs, increased collection frequency, waste in sealed sacks, and use of hand sanitizer reduce exposure. Incidences of gastrointestinal problems, irritation of the eye and skin and symptoms of organic dust toxic syndrome have been reported in workers engaged in waste collection. Several studies reported a correlation between bioaerosol exposure level and reduced lung function as either a short or a long term effect; exposure to fungi and endotoxin is often associated with an inflammatory response in exposed workers. However, a better understanding of the effect of specific microbial species on health outcomes is needed to proceed to more reliable risk assessments. Due to the increasing recycling effort and to the effects of global warming, exposure to biological agents in this working sector is expected to increase. Therefore, it is important to look ahead and plan future measures as well as improve methods to prevent long and short-term health effects.

A characterization of bioaerosols in biowaste pretreatment plants in relation to occupational health

Occupational exposure to microorganisms can be associated with adverse health outcomes. In this study, we assessed exposure to bioaerosols in two biowaste pretreatment plants in Denmark, which differed in location (city or countryside) and how they were built ('closed-off processes' or 'open processes'). Bioaerosol exposures were characterized by microbial concentrations in personal, stationary, sedimented dust, and hand samples, and their size distribution was assessed. Furthermore, species were identified by matrix-assisted laser desorption-ionisation time-of-flight mass spectrometry (MALDI-TOF MS), and inhalable dust, endotoxin, biofilm production, the total inflammatory potential, and fungicide resistance to four fungicides (amphotericin B, caspofungin acetate, itraconazole, voriconazole) were determined. Bacterial and fungal concentrations were on average (GM) in the order of 10⁴ cfu/m³, but ranged from 10² to 10⁸ cfu/m³. Several species which may cause health problems were identified. Personal endotoxin exposures were on average 28 EU/m³, but both personal and stationary samples ranged from 0.6 to 2035 EU/m³. Bioaerosols had the potential to form biofilms and to induce inflammation as measured in a human cell line. Exposures were higher in the plants that outdoor reference values. Higher exposures were found in the 'open process' plant, such as in microbial concentrations, species richness, endotoxin, biofilm production, and the total inflammatory potential. Six out of 28 tested Aspergillus fumigatus isolates were resistant to fungicides (amphotericin B and voriconazole). In conclusion, there is a high exposure to bioaerosols during work in biowaste pretreatment plants, however, results also suggests that how the plant is built and functions may affect the exposures.

Characteristics of microbial aerosol particles dispersed downwind from rural sanitation facilities: Size distribution, source tracking and exposure risk

Bioaerosols containing pathogens released from waste and wastewater treatment facilities pose potential health risks to workers on-site and residents downwind. In this study, sampling sites were set up at rural garbage stations (GS-1 and GS-2) and sewage treatment station (STS) to investigate the emission and diffusion characteristics of bioaerosols. High-throughput sequencing was utilized to assay the intestinal bacteria population, while the health risks associated with bioaerosols exposure were estimated based on average daily dose rates (DD). Traceability analysis was used to determine the percentages of intestinal bacteria from GS-1, GS-2 and STS. The recorded emission levels of bioaerosols in the air surrounding GS-1, GS-2, and STS were 5053, 6299, and 4795 CFU/m³, containing 1599, 2244, and 2233 CFU/m³ of intestinal bacteria, respectively. Most of the bioaerosols were coarse particles with size larger than 4.7 μm. Methylobacterium, Rhizobium, Pseudomonas, Enterobacteriaceae, and Brucella presented in the air were originally in rural waste and wastewater. STS and GS-2 were potential sources of intestinal bacteria. With increasing distance from the sources, the concentration of bioaerosols decreased gradually. On-site workers and residents were predominantly affected by bioaerosols through inhalation. The exposure risks via inhalation and skin contact for children were much higher than that for adults. The purpose of this study was to provide preliminary data for bioaerosols control and their risks reduction released from rural sanitation facilities.

Presence and variability of culturable bioaerosols in three multi-family apartment buildings with different ventilation systems in the Northeastern US

Bioaerosol concentrations in residential buildings located in the Northeastern US have not been widely studied. Here, in 2011-2015, we studied the presence and seasonal variability of culturable fungi and bacteria in three multi-family apartment buildings and correlated the bioaerosol concentrations with building ventilation system types and environmental parameters. A total of 409 indoor and 86 outdoor samples were taken. Eighty-five percent of investigated apartments had indoor-outdoor (I/O) ratios of culturable fungi below 1, suggesting minimal indoor sources of fungi. In contrast, 56% of the apartments had I/O ratios for culturable bacteria above 1, indicating the prominence of indoor sources of bacteria. Culturable fungi I/O ratios in apartments serviced by central heating, ventilation, and air-conditioning (HVAC) system were lower than those in apartments with window AC. The type of ventilation system did not have a significant effect on the presence of indoor culturable bacteria. A significant positive association was determined between indoor dew point (DP) levels and indoor culturable fungi (P < .001) and bacteria (P < .001), regardless of ventilation type. Also, residents in apartments with central HVAC did not experience extreme DP values. We conclude that building ventilation systems, seasonality, and indoor sources are major factors affecting indoor bioaerosol levels in residential buildings.

Assessment of airborne particles and bioaerosols concentrations in a waste recycling environment in Brazil

This study aims to assess the concentrations of size-fractioned particle mass (PM_1.0, PM_2.5, PM_4.0, PM₁₀) and number (PNC_0.3, PNC_0.5, PNC_1.0, PNC_2.5), bacteria, and fungi in a Materials Recycling Facility (MRF) in Brazil. The measurements were performed inside the waste processing shed (P1) and in the outdoor environment (P2) during working days in winter and spring of 2017, and summer of 2019. A total of 2,400 min of PM, 1,440 min of PNC, and 216 samples of bioaerosols were collected in the morning and afternoon. P1 has the strongest air contamination with mean values of 475.5 ± 563.7 µg m⁻³ for PM₁₀, 58.6 ± 36.0 cm⁻³ for PNC_0.3, 1,088.8 ± 825.2 colony-forming units per cubic meter (CFU m⁻³) for bacteria, and 2,738.3 ± 1,381.3 CFU m⁻³ for fungi. The indoor/outdoor ratios indicated the large influence of indoor sources due to the activities performed inside P1 that promote the generation and resuspension of pollutants. Gram-positive bacteria dominated with 58.6% of indoor samples. Overall, our results show a critical indoor air quality situation in a Brazilian MRF, which may cause several health risks for waste pickers. Finally, we call attention to the lack of occupational exposure limits for bioaerosols in industrial workplaces and mainly in MRFs.

Are workers from waste sorting industry really protected by wearing Filtering Respiratory Protective Devices? The gap between the myth and reality

One of the solutions for decreasing the workers' exposure to bioburden is the use of Filtering Respiratory Protective Devices (FRPD). As such it is important to determine whether these devices are fulfilling their protective role. This is the basis of the current study, aimed at characterizing bioburden retained by 120 FRPD (both in interior layers and in exhalation valves) through culture based-methods and molecular tools and also via analysis of antifungal resistance and mycotoxins profile. Our results show that Gram - Bacteria are present at a higher prevalence than total bacteria in both matrixes. Regarding fungal identification, Chrysonilia sitophila presented the highest prevalence on interior layers (55.1% on malt extract agar (MEA) supplemented with chloramphenicol (0.05%); 59.6% on dichloran-glycerol agar (DG18)), whereas on exhalation valves Aspergillus sp. presented the highest prevalence on MEA (6.8%) and C. sitophila on DG18 (36.3%). Among Aspergillus genera, section Fumigati was the one with the highest prevalence in both matrices. Aspergillus sp. was the most prevalent on exhalation valves (75.0% ITRA) in the screening of azole resistance. Fumigati section was the most abundant Aspergillus sp. detected on the interior layers (33.33%, 40 samples out of 120) and on the exhalation valves (1.66%, 2 samples out of 120). The interior layers and exhalation valves from workers with more waste contact showed an increased exposure to bioburden. This study showed that FRPD can have high levels of bioburden, toxigenic fungal strains and Aspergillus sections with reduced susceptibility to the tested azoles and can be used as a passive sampling method since it mimics the results obtained by active methods in previous studies. The gathered information will be useful to prioritize multiple interventions on workers' education or even on FRPD replacement frequency.

The effect of the waste disposal crisis on the rates of hospitalization due to acute diarrheal illness in a middle-income country: Retrospective chart review

BACKGROUND

A waste disposal crisis occurred in Lebanon leading to the accumulation of garbage in the streets of Beirut. It is not clear whether such a limited crisis of improper waste disposal will lead to more diarrhea illnesses. The purpose of this study is to compare the rates of admissions due to diarrhea and characterize the illness among adults and children before, during and after the garbage crisis.

MATERIALS AND METHODS

This study is an observational retrospective in-patient chart review extending over four time intervals: pre-crisis, major crisis, minor crisis, and post-crisis periods. Hospital admissions due to diarrhea or gastroenteritis were included. Descriptive analysis of the following was done: characteristics of the present illness at the time of admission, stool and lab tests ordered and management of the diarrhea illness.

RESULTS

There was an increase in admission rates due to diarrhea in the months of the crisis as compared to pre and post-crisis months. The severity of diarrheal illness and the management of admitted patients were almost the same across the four periods. Rota virus diarrheal outbreak was noted during the major crisis among children less than 2 years old, and adults above 18 years old.

CONCLUSIONS

Despite an increase in the rates of admissions due to diarrhea during the garbage crisis, the severity of the diarrhea illness did not differ. This may indicate that physicians and patients were more worried and utilized more health services. However, Rota outbreaks may be more prominent with improper garbage disposal.

Measures to reduce the exposure of waste collection workers to handborne and airborne microorganisms and inflammogenic dust

Waste collection is associated with various health symptoms. The aims of this study were to obtain knowledge about exposure to bacteria, fungi, and endotoxin during waste collection, and to study whether it is possible to reduce the exposures and the total inflammatory potential (TIP) of those exposures through simple interventions. The study was performed with an initial baseline exposure assessment, a second assessment with intervention workers only, and a third with intervention and reference workers. The waste collection workers were exposed to 7.8 × 10³ cfu bacteria/m³, 1.4 × 10⁴ cfu fungi/m³, and 92 endotoxin units/m³ (geometric mean values). The potential exposures in the truck cabs were up to 23 times higher than outdoor reference concentrations. For the intervention trucks and workers, airborne fungi in the truck cab were reduced; fungi, bacteria, and yeasts on the steering wheels were reduced; and the concentration of fungi on the workers' hands was reduced. Exposures were typically highest during collection of mixed household waste, in the summer, and for collection using trucks with low loading height. The TIP was highest for the reference group sampling mixed household waste, using trucks with low loading height, in the summer. Endotoxin, bacteria, and fungi contributed to the TIP of 42 personal exposure assessments. CONCLUSION: Motivating workers to reduce exposure through simple interventions improved hand and truck cab hygiene, but only slightly reduced personal exposure to airborne bioaerosols. Exposure can be reduced by only using trucks with high loading height.

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

Activities associated with the open dumping of municipal solid waste has the potential for greater impact on the environment and public health compared to other forms of waste-to-land treatment of such wastes. However, there is a lack of quantitative data on the exposure to bioaerosols from open dumpsites, hence impeding the development of effective interventions that would reduce the risk of respiratory symptoms among scavengers and waste workers at such dumpsites. This study investigated exposure to bioaerosols at Olusosun open dumpsite, Lagos Nigeria using three methodologies; (1) Conducting a cross-sectional survey on the respiratory health of the population on the dumpsite, (2) Measuring bioaerosol concentrations in the ambient air by measuring four bioaerosols indicator groups (total bacteria, gram-negative bacteria, Aspergillus fumigatus and total fungi) using a Anderson six stage impactor sampler, (3) Measuring activity related exposures to bioaerosols using an SKC button personal sampler. After a cross sectional health survey of 149 participants (waste workers, scavengers, middlemen, food vendors and business owners), smokers reported higher symptoms of chronic cough (21%) and chronic phlegm (15%) compared to non-smokers (chronic cough 15%, chronic phlegm 13%). Years of work > 5 years showed no statistically significant association with chronic phlegm (OR 1.2, 95% CI 0.4-3.4; p > 0.05) or asthma (OR 1.8, 95% CI 0.6-5.2; p > 0.05). At the 95th percentile, the concentration of total bacteria was the highest (2189 CFU/m³), then gram negative bacteria (2188 CFU/m³), total fungi (843 CFU/m³) and Aspergillus fumigatus (441 CFU/m³) after ambient air sampling. A comparison of the data showed that the activity-based sampling (undertaken using body worn personal sampler) had higher bioaerosols concentrations (10⁴ -10⁶ CFU/m³), i.e. 2-3 logs higher than those recorded from static ambient air sampling. Bioaerosol exposure was highest during scavenging activities compared to waste sorting and site supervision. Particle size distributions showed that 41%, 46%, 76% and 63% of total bacteria, gram-negative bacteria, Aspergillus fumigatus and total fungi respectively were of respirable sizes and would therefore be capable of penetrating deep into the respiratory system, posing a greater human health risk. This study has shown that exposure to bioaerosols can be associated with activities undertaken at open dumpsites and may contribute to the high prevalence of the chronic respiratory symptoms among the workers in such environments.

Density assessment and mapping of microorganisms around a biocomposting plant in Sanandaj, Iran

Exposure to microorganisms can cause various diseases or exacerbate the excitatory responses, inflammation, dry cough and shortness of breath, reduced lung function, chronic obstructive pulmonary disease, and allergic response or allergic immune. The aim of the present study was to investigate the density of microorganisms around the air of processing facilities of a biocomposting plant. Each experiment was carried out according to ASTM E884-82 (2001) method. The samples were collected from inhaled air in four locations of the plant, which had a high traffic of workers and employees, including screen, conveyor belt, aerated compost pile, and static compost pile. The sampling was repeated five times for each location selected. The wind speed and its direction were measured using an anemometer. Temperature and humidity were also recorded at the time of sampling. The multistage impactor used for sampling was equipped with a solidified medium (agar) and a pump (with a flow rate of 28.3 l/m) for passing air through the media. It was found that the mean density of total bacteria was >1.7 × 10³ cfu/m³ in the study area. Moreover, the mean densities of fungi, intestinal bacteria (Klebsiella), and Staphylococcus aureus were 5.9 × 10³, 3.3 × 10³, and 4.1 × 10³ cfu/m³, respectively. In conclusion, according to the findings, the density of bacteria and fungi per cubic meter of air in the samples collected around the processing facilities of the biocomposting plant in Sanandaj City was higher than the microbial standard for inhaled air.

Waste Workers’ Exposure to Airborne Fungal and Bacterial Species in the Truck Cab and During Waste Collection

A large number of people work with garbage collection, and exposure to microorganisms is considered an occupational health problem. However, knowledge on microbial exposure at species level is limited. The aim of the study was to achieve knowledge on waste collectors’ exposure to airborne inhalable fungal and bacterial species during waste collection with focus on the transport of airborne microorganisms into the truck cab. Airborne microorganisms were collected with samplers mounted in the truck cab, on the workers’ clothes, and outdoors. Fungal and bacterial species were quantified and identified. The study showed that the workers were exposed to between 112 and 4.8×10⁴ bacteria m⁻³ air and 326 and 4.6×10⁴ fungi m⁻³ air. The personal exposures to bacteria and fungi were significantly higher than the concentrations measured in the truck cabs and in the outdoor references. On average, the fungal and bacterial concentrations in truck cabs were 111 and 7.7 times higher than outdoor reference measurements. In total, 23 fungal and 38 bacterial species were found and identified. Most fungal species belonged to the genus Penicillium and in total 11 Penicillium species were found. Identical fungal species were often found both in a personal sample and in the same person’s truck cab, but concentrations were on average 27 times higher in personal samples. Concentrations of fungal and bacterial species found only in the personal samples were lower than concentrations of species also found in truck cabs. Skin-related bacteria constituted a large fraction of bacterial isolates found in personal and truck cab samples. In total, six Staphylococcus species were found. In outdoor samples, no skin-related bacteria were found. On average, concentrations of bacterial species found both in the truck cab and personal samples were 77 times higher in personal samples than in truck cab samples. In conclusion, high concentrations of fungi were found in truck cabs, but the highest concentrations were found in personal samples; fungal and bacterial species found in high concentrations in personal samples were also found in truck cabs, but in lower concentrations indicating that both fungi and bacteria are transported by the workers into the truck cab, and are subsequently aerosolized in the truck cab.

Occupational Exposure to Diesel Particulate Matter in Municipal Household Waste Workers

OBJECTIVE

The purposes of this study were to determine the following: 1) the exposure levels of municipal household waste (MHW) workers to diesel particulate matter (DPM) using elemental carbon (EC), organic carbon (OC), total carbon (TC), black carbon (BC), and fine particulate matter (PM 2.5) as indicators; 2) the correlations among the indicators; 3) the optimal indicator for DPM; and 4) factors that influence personal exposure to DPM.

METHODS

A total of 72 workers in five MHW collection companies were assessed over a period of 7 days from June to September 2014. Respirable EC/OC samples were quantified using the thermal optical transmittance method. BC and PM 2.5 were measured using real-time monitors, an aethalometer and a laser photometer. All results were statistically analyzed for occupational and environmental variables to identify the exposure determinants of DPM.

RESULTS

The geometric mean of EC, OC, TC, BC and PM 2.5 concentrations were 4.8, 39.6, 44.8, 9.1 and 62.0 μg/m3, respectively. EC concentrations were significantly correlated with the concentrations of OC, TC and BC, but not with those of PM 2.5. The exposures of the MHW collectors to EC, OC, and TC were higher than those of the drivers (p<0.05). Workers of trucks meeting Euro 3 emission standard had higher exposures to EC, OC, TC and PM 2.5 than those working on Euro 4 trucks (p<0.05). Multiple regression analysis revealed that the job task, European engine emission standard, and average driving speed were the most influential factors in determining worker exposure.

CONCLUSIONS

We assessed MHW workers' exposure to DPM using parallel sampling of five possible indicators. Of these five indicators, EC was shown to be the most useful indicator of DPM exposure for MHW workers, and the job task, European emission standard, and average driving speed were the main determinants of EC exposure.

Effect of temperature on bacterial emissions in composting of swine manure

Swine manure was subjected to laboratory scale composting in order to quantify bioaerosols, i.e., airborne culturable bacteria and endotoxin, in the exhaust gas, which provided details on the effect of temperature on bacterial emissions. The concentration of airborne bacteria reached 31,250 colony-forming units (CFU)/m(3) during the thermophilic stage of composting, and positively correlated with the temperature profile of the compost pile. Initially, the endotoxin concentration was 1820 endotoxin units (EU)/m(3), but it decreased exponentially as the composting process proceeded. The temperature can be an excellent indicator of bacterial emissions during the composting process, indicating that the composting process requires a consistently high temperature to ensure sanitization of both compost and bacterial emissions. The cumulative emission data showed that emission factors was 11.2-13.5 CFU/g dry swine manure and that of endotoxin was 0.5-0.9 EU/g dry swine manure. The bacterial diversity in the bioaerosol was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis, revealing the presence of various gram-negative bacterial consortia.

Respiratory disorders among municipal solid waste collectors in Mansoura, Egypt: a comparative study

ABSTRACT This research assessed the prevalence of respiratory complaints and the occupational risk factors among municipal solid waste (MSW) collectors. A comparative study was conducted upon MSW collectors in Western Municipality of Mansoura. Sociodemographic and occupational data were collected. Clinical examination and respiratory function measurements were performed. The prevalence of respiratory complaints during the past 12 months was higher among MSW collectors than the service worker group. Older age, cigarette smoking, and longer duration of employment were independently associated with impaired FEV1 (OR = 0.22, 7.2, 0.09, respectively). Older age group of collectors was independently associated with impaired FVC (OR = 0.34). Longer duration of employment was independently associated with impaired FEV1/ FVC (OR = 0.09). Respiratory complaints were prevalent among MSW collectors due to lack of engineering, medical and legislative measures.

Characteristics of particulate matter generated while handling municipal household waste

OBJECTIVES

This study was conducted to assess the size characteristics of particulate matter (PM) generated during waste collection and sorting, and to assess the effect of the type of waste-handling activity on levels of coarse and fine PM.

METHODS

A portable aerosol spectrometer calibrated to 1.2 //min was used to monitor PM generated during four types of waste-handling activities. The types of PM measured included inhalable particulate matter (IPM), PM10, respirable particulate matter (RPM), PM2.5 and PM1. Twenty-eight data sets with 3,071 subsets recorded every 6 sec were categorized according to occupational and environmen¬tal classifications, including type of waste-handling activity. An ANOVA was used to compare PM levels characterized by size. Significant variables with p-values <0.25 were included in a multiple regression model for predicting levels of each PM.

RESULTS

The average levels of PM10 and PM2.5 greatly exceeded the air-quality levels enforced by the Korean Ministry of the Environment. The highest PM2.5 fine-particle levels monitored were during waste-transfer work, while the highest IPM and PM10 coarse-particle levels monitored were during waste-sorting work. The type of waste-collection activity was the only factor that significantly affected both PM25 and IPM, accounting for 36% (p=0.0034) and 40% (p=0.0049), respectively, of the observed variations. None of the factors affected PM10 or RPM levels.

CONCLUSIONS

Waste-collection and Waste-transfer work may be associated with the generation of high levels of fine PM, which can be influenced by environ Workmental conditions such as traffic levels and the type of waste transport vehicle.

Possible role of plasma ceruloplasmin and erythrocyte sedimentation rate in assessing compliance with occupational hygiene and safety practices in waste management workers

OBJECTIVES

Work-related health and safety risks are common among waste management workers (WMWs). This study investigated the level of compliance with safety measures in relation to levels of inflammatory markers among WMWs in Sagamu, South-West Nigeria.

MATERIALS AND METHODS

WMWs comprising 30 cart pushers (CPs) and 50 truck users (TUs) were recruited alongside 45 people from the normal population as control. Data on health complaints were obtained from questionnaire surveys. Inflammation was assessed by measuring plasma ceruloplasmin (Cp), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and albumin.

RESULTS

WMWs exhibited a significantly higher prevalence of respiratory and gastrointestinal symptoms and poor compliance with health and safety measures. Significant (P < 0.001) differences were observed in the use of masks, hand gloves, protective clothing, and footwear between TUs and CPs. ESR, Cp, and CRP increased significantly (P < 0.001) by 145, 28.7, and 42.5% in TUs and by 164, 50.5, and 74.3% in CPs, respectively, relative to control. Negative correlation was observed between use of mask (r = -0.225, P < 0.01), use of gloves (r = -0.184, P < 0.05), and Cp and between ESR and washing of hands with soap (r = -0.185, P < 0.05). The use of goggles (r = +0.285, P < 0.001), washing of hands with soap (r = +0.203; P < 0.01), use of masks (r = +0.317, P < 0.001), and use of gloves correlated positively in WMWs.

CONCLUSIONS

A higher prevalence of work-related symptoms and elevated inflammatory markers in WMWs was related to poor compliance with safety measures. ESR and Cp may be useful predictors of occupational hygiene and compliance with safety measures among Nigerian WMWs.

Work-related health symptoms among compost facility workers: a cross-sectional study

Background

Industrial composting is a relatively new and expanding activity. Several studies indicate that compost workers are at risk to develop health symptoms. The aim of this study was to assess the prevalence of work-related health symptoms among compost workers compared with control subjects.

Methods

A questionnaire was distributed among 62 workers (31 exposed and 31 non-exposed workers). Data were analyzed using simple and multiple logistic regression analyses.

Results

Workers exposed to organic dust reported significantly more often respiratory, irritation (e.g., eyes, nose and throat), gastrointestinal, and skin symptoms than the non-exposed group. Moreover, all work-related symptoms were significantly more often reported by exposed than non-exposed workers. After adjustment for smoking status and age, the associations between exposure and respiratory, gastrointestinal, and skin symptoms remained statistically significant, in particular if these symptoms were work-related.

Conclusions

This study confirms that workers at compost facilities are at risk to develop occupational health problems, most likely related to organic dust exposure.

Fungal and microbial volatile organic compounds exposure assessment in a waste sorting plant

In the management of solid waste, pollutants over a wide range are released with different routes of exposure for workers. The potential for synergism among the pollutants raises concerns about potential adverse health effects, and there are still many uncertainties involved in exposure assessment. In this study, conventional (culture-based) and molecular real-time polymerase chain reaction (RTPCR) methodologies were used to assess fungal air contamination in a waste-sorting plant which focused on the presence of three potential pathogenic/toxigenic fungal species: Aspergillus flavus, A. fumigatus, and Stachybotrys chartarum. In addition, microbial volatile organic compounds (MVOC) were measured by photoionization detection. For all analysis, samplings were performed at five different workstations inside the facilities and also outdoors as a reference. Penicillium sp. were the most common species found at all plant locations. Pathogenic/toxigenic species (A. fumigatus and S. chartarum) were detected at two different workstations by RTPCR but not by culture-based techniques. MVOC concentration indoors ranged between 0 and 8.9 ppm (average 5.3 ± 3.16 ppm). Our results illustrated the advantage of combining both conventional and molecular methodologies in fungal exposure assessment. Together with MVOC analyses in indoor air, data obtained allow for a more precise evaluation of potential health risks associated with bioaerosol exposure. Consequently, with this knowledge, strategies may be developed for effective protection of the workers.

Health and safety in waste collection: Towards evidence-based worker health surveillance

BACKGROUND

Waste collectors around the world are at risk for work-related disorders and injuries. The aim of this study was to assess work demands, acute physiologic responses, illnesses, and injuries as a starting point for worker health surveillance (WHS).

METHODS

A systematic search was performed in PubMed and Embase on work demands, acute bodily responses, health, and injuries. A quality assessment and evidence synthesis was performed.

RESULTS

From a total of 379 retrieved studies, 50 studies fulfilled the inclusion criteria. Waste collecting varied from informal manual gathering to semi-automated systems. Most studies ("number of studies") on work demands and/or acute bodily responses addressed bioaerosols (14). Studies of health effects addressed respiratory complaints (8), and those on injuries addressed acute musculoskeletal disorders (3). Strong evidence is available that exposure to bioaerosols exceeds recommendations. Moderate evidence is available for an increased risk of respiratory complaints and musculoskeletal injuries, with significant odds ratios reported varying between 1.9-4.1 and 1.5-3.3, respectively. Limited evidence exists for gastrointestinal disorders and hearing loss.

CONCLUSIONS

WHS in waste collection is warranted for early detection of respiratory, gastrointestinal, and musculoskeletal disorders, and hearing loss.

Respiratory health of municipal solid waste workers

BACKGROUND

There is an increasing evidence that the incidence of work-related pulmonary problems is greater in waste collectors than in the general workforce.

AIMS

To evaluate the respiratory health of municipal solid waste workers (MSWWs).

METHODS

One hundred and eighty-four municipal employees of Keratsini (104 MSWWs and 80 controls) participated in a cross-sectional study. All participants were asked to fill in a slightly modified version of the Medical Research Council questionnaire. Lung function was evaluated by spirometry.

RESULTS

Spirometry revealed reduced mean forced vital capacity (FVC) and forced expiratory volume in 1 s (as a percentage of predicted values) in MSWWs compared with controls. After adjustment for smoking status, only the decline in FVC was statistically significant (P < 0.05). Prevalence of all respiratory symptoms was higher in MSWWs than in controls. After adjustment for confounding factors, the difference reached statistical significance (P < 0.05) for morning cough, cough on exertion and sore throat.

CONCLUSIONS

The results of this cross-sectional study indicate a higher prevalence of respiratory symptoms and a greater decrease in lung function in MSWWs. A number of limitations such as the relatively small size of population and the 'healthy worker' effect should be taken into account.

Indicadores infecciosos e inflamatórios entre trabalhadores da limpeza urbana em São Paulo

O objetivo deste trabalho foi comparar agravos à saúde entre grupos funcionais de trabalhadores da limpeza urbana (TLU) decorrentes de exposição biológica do contato com os Resíduos Sólidos (RS) em São Paulo, 2007. Para tal, amostras dos grupos de TLU e um grupo Controle de servidores ferroviários realizaram entrevistas, contagens sanguíneas, provas de atividade inflamatória, marcadores sorológicos de infecção e exame protoparasitológico de fezes.Ao término, foram avaliados 217 indivíduos. O grupo Controle relatou menor cobertura vacinal para o tétano, enquanto os Varredores tiveram a menor proporção de cobertura para a hepatite B. Os Motoristas usaram mais antibióticos e apresentaram o número de leucócitos mais elevado quando comparados aos Controles. Os Motoristas apresentaram também maiores médias de neutrófilos e monócitos quando comparados aos Varredores. A presença de parasitas nas fezes foi mais frequente entre os Varredores e os Coletores quando comparados aos Controles. Os grupos de Coleta, Transbordo e Aterro apresentaram indicadores de infecções respiratórias e de atividade inflamatória sistêmica similares aos Controles. Não foram observadas diferenças entre episódios de sinusites, pneumonias, marcadores séricos de atividade inflamatória, contato com o vírus da hepatite B ou com a estreptolisina O entre os grupos estudados.

Distribution characteristics of airborne bacteria and fungi in the feedstuff-manufacturing factories

The objective of the study is to investigate the distribution patterns of airborne bacteria and fungi in three feedstuff-manufacturing factories in Korea. The geometric mean (+/-GSD) levels of airborne bacteria and fungi in the feedstuff-manufacturing factory were 113(+/-18)cfu/m(3) and 89(+/-5)cfu/m(3) for pelleting process and 198(+/-5)cfu/m(3) and 124(+/-12)cfu/m(3) for powdering process, respectively. The percentage of respirable (0.65-4.7 microm) and total (>4.7 microm) concentration of airborne bacteria and fungi in the feedstuff-manufacturing factory ranged from 60% to 90% and were higher in pelleting process than powdering process. The ratio of indoor concentration and concentration in ventilation air from outside for airborne bacteria and fungi exceeded 1.0 regardless of types of feedstuff manufacture process. The predominant airborne microorganisms in the feedstuff-manufacturing factory were Staphylococcus spp., Micrococcus spp., Corynebacterium spp. and Bacillus spp. for airborne bacteria and Cladosporium spp., Penicillium spp. and Aspergillus spp. for airborne fungi, respectively. Based on the result of the study, there would be an association between relative humidity among environmental factors and airborne microorganism's bioactivity.

Baseline levels of bioaerosols and volatile organic compounds around a municipal waste incinerator prior to the construction of a mechanical-biological treatment plant

New waste management programs are currently aimed at developing alternative treatment technologies such as mechanical-biological treatment (MBT) and composting plants. However, there is still a high uncertainty concerning the chemical and microbiological risks for human health, not only for workers of these facilities, but also for the population living in the neighborhood. A new MBT plant is planned to be constructed adjacently to a municipal solid waste incinerator (MSWI) in Tarragona (Catalonia, Spain). In order to evaluate its potential impact and to differentiate the impacts of MSWI from those of the MBT when the latter is operative, a pre-operational survey was initiated by determining the concentrations of 20 volatile organic compounds (VOCs) and bioaerosols (total bacteria, gram-negative bacteria, fungi and Aspergillus fumigatus) in airborne samples around the MSWI. The results indicated that the current concentrations of bioaerosols (ranges: 382-3882, 18-790, 44-926, and <1-7 CFU/m(3) for fungi at 25 degrees C, fungi at 37 degrees C, total bacteria, and gram-negative bacteria, respectively) and VOCs (ranging from 0.9 to 121.2 microg/m(3)) are very low in comparison to reported levels in indoor and outdoor air in composting and MBT plants, as well in urban and industrial zones. With the exception of total bacteria, no correlations were observed between the environmental concentrations of biological agents and the direction/distance from the facility. However, total bacteria presented significantly higher levels downwind. Moreover, a non-significant increase of VOCs was detected in sites closer to the incinerator, which means that the MSWI could have a very minor impact on the surrounding environment.

Domestic waste composting facilities: a review of human health risks

In the management of municipal solid waste (MSW), the sorting-composting approach presents many advantages. However, since MSW contains a number of chemical and biological agents, the compost should not be necessarily a harmless product. These contaminants may expose different populations to health hazards, ranging from the composting plant workers to the consumers of vegetable products grown in soils treated with compost. Recent information concerning health risks derived from occupational exposure to organic dusts, bioaerosols and microorganisms in MSW composting plants is here reviewed. An evaluation of the potential health risks of volatile organic compounds (VOCs) released during composting is also included. Taking into account the potential biological and chemical risks, an exhaustive control of the workers employed in MSW composting facilities is clearly recommendable. Moreover, because the compost derived from the organic fraction of MSW can contain a number of metals and persistent organic pollutants, as well as microbial and fungi toxins, any compost that may mean a health risk for the population should not be commercialized.

Size distributions of total airborne particles and bioaerosols in a municipal composting facility

Size distributions of total airborne particles and bioaerosols were measured in a full-scale composting facility, using an optical particle counter and an agar-inserted six-stage impactor, respectively. Higher concentrations of total airborne particles and bioaerosols were detected at a sampling location near the screening process preceded by the composting process than at sampling locations in the composting process. At the sampling location near the screening process, the concentrations of total airborne particles were approximately 10(8)particles/m3 at the size of 0.3 microm and 10(5)particles/m3 at 6.2 microm. The concentration of bioaerosols was about 10(4)CFU/m3 in each stage of 7.0 microm (1st stage), 7.0-4.7 microm (2nd), 4.7-3.3 microm (3rd), 3.3-2.1 microm (4th), 2.1-1.1 microm (5th) and 1.1-0.65 microm (6th). Most of submicron particles smaller than 1 microm among the total airborne particles were believed to originate from the ambient air.