Volatile organic compounds and bioaerosols in the vicinity of a municipal waste organic fraction treatment plant. Human health risks

Disruption and recovery of outdoor bioaerosols before, during, and after the COVID-19 outbreak at a campus in Central China: pathogen composition, particle size distribution, influencing factors, and exposure risk

Before (2019), during (2020), and after (2021) the COVID-19 outbreak, different response methods and measures were taken on campuses to control the spread of COVID-19 within schools. These response methods may have changed the outdoor bioaerosol characteristics, which may affect staff and student health. Therefore, we analyzed the bacterial concentrations, particle size distribution, microbial populations, exposure risks, and environmental influences of bioaerosols at a campus before, during, and after the COVID-19 outbreak. This study used eight-stage Andersen samplers to collect and analyze culturable bacteria in bioaerosols from various locations, high-throughput sequencing to analyze microbial species, principal component analysis to compare differences in samples, RDA to investigate the effects of environmental factors on bioaerosols, and hazard quotient (HQ) and BugBase to evaluate human health risks. The study findings revealed that average bacterial concentrations before, during, and after COVID-19 were 75 CFU m-3, 136 CFU m-3, and 78 CFU m-3, respectively. Moreover, the average percentage of bacteria attached to PM2.5 was 49.2%, 42.7%, and 29.9%, respectively. High-throughput sequencing revealed that species composition changed significantly during the three years of COVID-19. The proportion of Pantoea and Bacillus increased with the development of COVID-19 and these became the dominant strains after COVID-19, whereas Pseudomonas had the maximum proportion during COVID-19. Both risk assessment and BugBase phenotype prediction results indicated that the potential pathogenic risk was the highest in the outdoor environment of the campus during COVID-19 and that bioaerosol contamination was the most severe compared to the outdoor bioaerosol characteristics of the campus recovered after COVID-19.

ADMS simulation and influencing factors of bioaerosol diffusion from BRT under different aeration modes in six wastewater treatment plants

Bioaerosols produced by municipal wastewater treatment plants (MWTP) can spread in air, thereby polluting the atmosphere and causing safety hazards to workers and surrounding residents. In this study, the biological reaction tanks (BRTs) of six MWTPs undergoing typical processes in North China, Yangtze River Delta, and the Greater Bay Area were selected to set up sampling points and investigate the production characteristics of bioaerosols. The Atmospheric Dispersion Modelling System method was used to simulate the diffusion of bioaerosols in the MWTPs. The concentrations of bacteria and, specifically, intestinal bacteria in the bioaerosols ranged from 389 CFU/m³ to 1,536 CFU/m³ and 30 CFU/m³ to 152 CFU/m³, respectively, and the proportion of the intestinal bacteria was 8.85%. The concentration of soluble chemicals (SCs) in the bioaerosols was 18.36 μg/m³-82.19 μg/m³, and the main SCs found were Mg²⁺, Ca²⁺, and SO₄^2-. The proportion of intestinal bacteria (75.79%) produced via surface aeration by a BRT attached to large-sized bioaerosol particles was higher than that of a BRT undergoing the bottom aeration process (37.28%). The main microorganisms found in the bioaerosols included Moraxellaceae, Escherichia-Shigella, Psychrobacter, and Cyanobacteria. The generation of bioaerosols exhibited regional characteristics. The wastewater treatment scale, wastewater quality, and aeration mode were the main factors influencing bioaerosol production. Model simulation showed that, after 1 h, the diffusion distance of bioaerosol was 292 m-515 m, and the affected area was 42,895 m²-91,708 m². The diffusion distance and range of the bioaerosols were significantly correlated with the concentration at the bioaerosol source and the aeration mode adopted by the BRTs. Wind speed and direction were two environmental factors that affected the diffusion of bioaerosols. With an increase in the diffusion distance, the concentration of microorganisms, intestinal bacteria, ions, and fine particles in the bioaerosols decreased significantly, resulting in a corresponding reduction in the exposure risk. This study provides new insights to help predict bioaerosol risks at MWTPs and identify safe areas around MWTPs. The study also provides a basis for selecting safe MWTP sites and reducing bioaerosol pollution risks.

Characteristics, non-carcinogenic risk assessment and prediction by HYSPLIT of bioaerosol released from Hospital and Municipal Sewage, China

Bioaerosol is a new type of pollutant, which is related to the spread of many diseases. In particular, the bioaerosol produced in the hospital sewage treatment process contains many pathogenic bacteria, which will impact patients and surrounding residents. In this study, the biochemical tank (BRT) of the hospital sewage treatment station (HSTS) and municipal wastewater treatment plant (MWTP) were used as sampling points. The results showed that the concentration of bacteria (1843 CFU/m³) in bioaerosol produced by BRT of HSTS was higher than that in the air at BRT of MWTP (1278 CFU/m³). The proportion of small-size bacteria (<3.3 µm) in the air of HSTS and MWTP was similar. However, the abundance of small-size pathogenic bacteria in HSTS was higher than that in MWTP, such as Acinetobacter and Arcobacter. The dominant bacteria in HSTS and MWTP were different under different particle sizes. The dominant bacterial genera of bioaerosol in HSTS under different particle sizes were similar (Acinetobacter, Arcobacter, Comamonas); There were significant differences in the dominant bacterial genera of bioaerosol in MWTP under different particle sizes. The dominant strains with particle sizes ranging from 0 ∼ 0.43 µm were Acinetobacter (23.22%). Kocuria (15.13%) accounted for a relatively high proportion in the aerosol of 0.43 µm ∼ 0.65 µm. The dominant strains with particle sizes of 0.65 µm ∼ 1.1 µm and 1.1 µm ∼ 2.1 µm were relatively single, and Exiguobacterium and Paenibacillus accounted for 51.51% and 60.15%, respectively. Source tracker showed that most of the pathogenic bacteria in bioaerosols came from sewage. One hour later, the concentration of particulate matter in the place 200 m away from BRT of HSTS (1 × 10^-10 mg/m³) was higher than that in MWTP (1 × 10^-11 mg/m³). The hazard quotient (HQ) of people around HSTS (HQ_male: 1.70 × 10^-1; HQ_female: 1.36 × 10^-1) was higher than that of MWTP (HQ_male: 1.18 × 10^-1; HQ_female: 9.40 × 10^-2). Pathogenic bacteria (Acinetobacter, Arcobacter) were detected in HSTS and MWTP and the BugBase phenotype prediction results showed potential pathogenicity. More attention should be paid to the protection of the people. It is suggested to strengthen the air sterilization treatment near HSTS according to the diffusion trajectory of bioaerosol, and the surrounding personnel should wear N95 and other protective masks.

The generation characteristics, pattern, and exposure risk of bioaerosol emitted in an A²O process wastewater treatment plant

Bioaerosols can be generated in wastewater treatment plants (WWTPs), they may contain pathogenic bacteria, cause disease transmission, and attract the public's attention. In this study, bioaerosols were collected from seven different stages of an A²O process WWTP. The component characteristics were analyzed by bacterial culture and high-throughput sequencing. The correlations in different processes were analyzed, and the health risks of bioaerosols produced were evaluated. The results showed that the concentration range of bacteria aerosol in the WWTP was 75 CFU/m³-706 CFU/m³. The concentration range of total suspended particles was 111.13 µg/m³-211.67 µg/m³, the primary water-soluble ions were Ca²⁺ and Cl⁻. In the air of each stage, the main bacteria were Cetobacterium, Bacteroides, Romboutsia, and the fungi were Fusarium, Alternaria, and Aspergillus. The dominant bacteria in the wastewater were Cetobacterium, Romboutsia, Stenotrophobacter, and the fungi were Fusarium, Aspergillus, and Mortierella. The total bacterial concentration and ion concentration in the aerobic section of the biochemical tank were the highest. The results of species composition and principal component analysis showed that the bacterial composition in the air at different processes was similar, while the bacteria in wastewater differed significantly. Among them, the wastewater bacteria in the aerobic section of the biochemical tank were closer to that in the air. Fungal results were similar to bacteria but not prominent. The bioaerosol exposure risk results show that the risk in each stage was acceptable (5.15 ×10⁻⁴-6.47 ×10⁻³). However, the exposure risk of bioaerosol was calculated by the total bacterial concentration. In fact, some pathogenic microorganisms such as Escherichia coli and Aspergillus flavus were detected in bioaerosols, which may cause hemorrhagic colitis, cancer and other diseases by swallowing and inhalation. Therefore, the risk might be underestimated and should be a cause of concern.

The changing pattern of bioaerosol characteristics, source and risk under diversity brush aerator speed

Bioaerosols containing pathogens released from wastewater treatment plants (WWTP) may pose potential health risks to workers on-site and residents downwind. In this study, sampling points were set up in the wastewater treatment facility to investigate the generation pattern of bioaerosols in the aeration tank section. High-throughput sequencing was utilized to assay the intestinal bacteria population, while the health risks associated with airborne bacteria were estimated based on average daily dose rates. The contribution of wastewater to bioaerosols was evaluated using the traceability analysis. As the rotational speed increased from 200 rpm to 800 rpm, the concentration of culturable bacteria increased from 397 CFU/m³ to 1611 CFU/m³, the proportion of bacteria attached to particles with an aerodynamic diameter larger than 4.7 µm increased from 30.41% to 48.44%, and the Shannon index of air samples increased from 1.032485 to 1.282065. Microbial composition, sources, and health risks of bioaerosols also changed as the rotational speed increased. The results showed that the predominant bacteria in the air at 200 rpm were Bacillus (78.78%), Paenibacillus (11.77%) and Lysinibacillus (1.40%). When the rotating speed reached 800 rpm, the dominant bacteria became Bacillus (55.50%), Acinetobacter (31.01%), and Paenarthrobacter (13.17%). The contribution of the wastewater to bioaerosols increased from 46.49% to 65.10%, in which surface water was the main source of bioaerosols (34.64% on average). Although the contribution of bottom water was lower than that of surface water, its contribution increased more, from 15.36% to 29.31%. The health risk of bioaerosols was 1.28 × 10^-2 on average, which increased with the increase of rotational speed. At the same exposure concentration, children (2.31 × 10^-2) have a higher exposure risk than adults (7.67 × 10^-3). This study is aimed at exploring the variation law of bioaerosols discharged from WWTP with oxidation ditch process and providing preliminary data for reducing its risk.

A rapid multiplex nucleic acid detection system of airborne fungi by an integrated DNA release device and microfluidic chip

Occupational health problems, such as asthma, in specific work environments arise from the presence of airborne fungi. Rapid detection of pathogenic airborne fungi is therefore important to reduce or avoid any adverse effects on staff health. Herein, we established a new integrated rapid Lyticase-Motor-Chemical reagent nucleic acid releasing (LMC) method for the release of fungal DNA. Aspergillus fumigatus, Aspergillus flavus, and Cryptococcus neoformans were chosen to evaluate the LMC method. The results of Loop-Mediated Isothermal Amplification (LAMP) analyses showed that this method could release the nucleic acid of 4 × 10⁴ fungal spores, equaling to 400 copies per microliter. This rapid multiplex nucleic acid detection system of airborne fungi included an integrated DNA release device and a portable microfluidic chip. The integrated DNA release device combined mechanical lysing and biochemical reagent treatment to automate DNA release. The microfluidic chip was capable of multiplex nucleic acid detection. The detection limit of this system was 4 × 10⁴ spores per test, meeting the requirement of early warnings. The whole analysis from the sample input to readout could be completed within 90 min, including 30 min for fungal DNA release and 45 min for LAMP analysis. The integrated DNA release device and microfluidic chip were portable, showing tremendous potential in point-of-care tests of airborne fungi.

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.

Health risks for the population living near petrochemical industrial complexes. 1. Cancer risks: A review of the scientific literature

Petrochemical complexes and oil refineries are well known sources of a wide range of environmental pollutants. Consequently, the potential harmful health effects of living near these facilities is a topic of concern among the population living in the neighborhood. Anyhow, the number of studies carried out on this issue is rather limited and, in some cases, results are even slightly contradictory. The present Review was aimed at assessing whether living in the vicinity of petrochemical industries and oil refineries is associated with a higher incidence of cancer and cancer mortality. In this sense, up to 23 investigations were found in PubMed and Scopus databases. According to the type of cancer, leukemia and other hematological malignancies were reported as the main types of cancer for populations living in the neighborhood of petrochemical industries. This was concluded based on studies performed in Taiwan, Spain, United Kingdom, Italy and Nigeria. In contrast, no association was found in 4 different investigations conducted in Sweden, Finland and USA with the same purpose. Other scientific studies reported a high incidence of lung and bladder cancer in Taiwan, Italy and USA, as well as an excess mortality of bone, brain, liver, pleural, larynx and pancreas cancers in individuals living near petrochemical complexes from Taiwan, Spain, Italy, United Kingdom and USA. Thus, human exposure to certain carcinogenic pollutants emitted from petrochemical industries might increase the incidence of some cancers and cancer mortality. Anyway, since the limited number of investigations conducted until now, further studies are required in order to corroborate -in a more generalized way-this conclusion.

Diurnal variation of BTEX at road traffic intersection points in Delhi, India: source, ozone formation potential, and health risk assessment

The present study was carried out to observe the variation of volatile organic compounds (VOCs) namely benzene, toluene, ethylbenzene, and xylene isomers (BTEX) at three different sites of Delhi, during 2016-2017. Four hourly sampling was carried out day and night separately. Results showed that BTEX concentration was highest in post-monsoon and lowest in monsoon season. Again, daily variation shows that benzene (47%) and toluene (35%) were more during night than day when it was 44% and 33% respectively. Mean concentration of BTEX was observed in following order: ethylbenzene ~ o-xylene < m,p-xylene < toluene < benzene, while overall seasonal variation was observed as follows: post-monsoon > summer > winter > monsoon. Possible emission sources of BTEX were also established through corresponding ratios of individual compounds. Xylene isomers together accounted highest ozone formation potential. The risk assessments of BTEX were carried out in terms of non-cancer (the hazard quotient, HQ) and cancer (the incremental lifetime cancer risk, ILCR) regarding the inhalation exposure only. It was observed that benzene and xylene isomers possessed higher HQs than ethylbenzene and toluene at all sites throughout the study. Again, benzene was found with higher mean ILCR (3.58 × 10^-5) than ethylbenzene (1.47 × 10^-5).

Emission characteristics of VOCs and potential ozone formation from a full-scale sewage sludge composting plant

Volatile organic compounds (VOCs) are the major components of the odor emitted from sewage sludge composting plants and are generally associated with odorous nuisances and health risks. However, few studies have considered the potential ozone generation caused by VOCs emitted from sewage sludge composting plants. This study investigated the VOC emissions from a full-scale composting plant. Five major treatment units of the composting plant were chosen as the monitoring locations, including the dewatered room, dewatered sludge, blender room, fermentation workshop, and product units. The fermentation workshop units displayed the highest concentration of VOC emissions at 2595.7 ± 1367.3 μg.m^-3, followed by the blender room, product, dewatered sludge, and dewatered room units, whose emissions ranged from 142.2 ± 86.8 μg.m^-3 to 2107.6 ± 1045.6 μg.m^-3. The detected VOC families included oxygenated compounds, alkanes, alkenes, sulfide compounds, halogenated compounds, and aromatic compounds. Oxygenated compounds, particularly acetone, were the most abundant compounds in all samples. Principal component analysis revealed that the dewatered room and dewatered sludge units clustered closely, as indicated by their similar component emissions. The product units differed from the other sampling units, as their typical compounds were methanethiol, styrene, carbon disulfide, and hexane, all of which were the products of the latter stages of composting. Among the treatment units, the fermentation workshop units had the highest propylene equivalent (propy-equiv) concentration. Dimethyl disulfide and limonene were the major contributors. Limonene had the highest propy-equiv concentration, which contributed to the increased atmospheric reactivity and ozone formation potential in the surrounding air. To control the secondary environmental pollution caused by the VOC emissions during sewage sludge composting, the emission of limonene and dimethyl disulfide must be controlled from the blender room and fermentation workshop units.

Effects of aeration on microbes and intestinal bacteria in bioaerosols from the BRT of an indoor wastewater treatment facility

The generation and emission of airborne bacteria from a biochemical reaction tank (BRT) for wastewater treatment was investigated by altering the aeration rate. The levels of bioaerosols increased from 715 ± 69 to 1597 ± 135 CFU/m³ (total airborne bacteria) and from 78 ± 6 to 359 ± 18 CFU/m³ (intestinal bacteria) as the aeration rate increased from 0.3 to 1.2 m³/h. Most airborne bacteria were attached to particles smaller than 4.7 μm at an aeration rate of 0.3 m³/h. They were found attached to larger particles (>4.7 μm) when the aeration rate increased to 1.2 m³/h. A similar phenomenon was observed for intestinal bacteria. The high-throughput sequencing technique was used to assay the microbial populations of the bioaerosols. Both microbial counts and diversity increased as the aeration rate increased. Brevundimonas (63.82%), Chryseobacterium (16.54%), and Micrococcaceae (12.37%) were the dominant intestinal bacteria at an aeration rate of 0.3 m³/h. Pseudochrobactrum (33.10%), Citrobacter (21.28%), and Yersinia (18.21%) were the dominant intestinal bacteria at an aeration rate of 1.2 m³/h. The level, particle size distribution, population structure, and diversity of the bioaerosols were all affected by aeration rate. The source tracker results indicated that water and the surrounding air were the two main bioaerosol sources. The contribution of water is greater at larger levels of aeration. Inhalation was the main pathway of microbial aerosol intake for people in the surrounding area. The exposure hazard quotients for adult males were generally higher than those for adult females. Necessary measures should be taken to ensure worker safety.

Relationships between emitted volatile organic compounds and their concentration in the pile during municipal solid waste composting

Composting operations taking place at municipal solid waste (MSW) treatment plants represent a source of volatile organic compounds (VOC) to the atmosphere. Understanding the variables governing the release of VOC at these facilities is crucial to assess potential health risks for site workers and local residents. In this work the changes in the VOC composition of a composting pile were monitored and compared to the VOC emmited from the same pile in order to understand the impact of composting operations on the release of VOC. More than one hundred VOC were indentified in the solid phase of the composting piles, which were dominated by terpenes (about 50% of the total amount of VOC) and in a lower quantity alcohols, volatile fatty acids and aromatic compounds. There was a reduction in the total concentration of VOC in the pile during composting, from 45 to 35 mg/kg, but the compostion and distribution of VOC families remained stable in the pile even in the mature compost. However, there was no correlation between the emitted VOC and their concentration in the composting pile. The VOC emission pattern was affected by the biological activity in the pile (measured by temperature, CO₂ evolution and the presence of CH₄ emissions). The highest VOC emissions were detected at early stages of the process, alongside with the generation of CH₄ in the pile, and then decreased sharply in the mature compost as a consequence of biodegradation and volatilisation. These results pointed to the importance of composting operation rather than the composition of the raw materials on the release of VOC in composting plants.

Main components of PM10 in an area influenced by a cement plant in Catalonia, Spain: Seasonal and daily variations

Particulate matter (PM) composition has a key role in a wide range of health outcomes, such as asthma, chronic obstructive pulmonary disease, lung cancer, cardiovascular disease, and death, among others. Montcada i Reixac, a municipality located in the Barcelona metropolitan area (Catalonia, Spain), for its location and orography, is an interesting case- study to investigate air pollution. The area is also characterized by the presence of different industrial emission sources, including a cement factory and a large waste management plant, as well as an intense traffic. In this study, PM₁₀ levels, trace elements, ions, and carbonaceous particles were determined for a long time period (2013-2016) in this highly polluted area. PM₁₀ samples were collected during six consecutive days in two campaigns (cold and warm) per year. A number of elements (As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Hg, Ho, K, La, Li, Hg, Mg, Mn, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Sr, Tb, Th, Ti, Tl, U, V, W, Y, Yb, and Zr), ions (Cl^-, SO₄^2-, NO₃^-, and NH₄⁺), and carbonaceous content (total carbon, organic plus elemental carbon, and CO₃^2-), were analysed. These data were used to identify the PM₁₀ main components: mineral matter, sea spray, secondary inorganic aerosols, organic matter plus elemental carbon, trace elements or indeterminate fraction. Although a clear seasonality (cold vs. warm periods) was found, there were no differences between working days and weekends. Obviously, the cement plant influences the surrounding environment. However, no differences in trace elements related with the cement plant activity (Al, Ca, Ni and V) between weekdays and weekends were noted. However, some traffic-related elements (i.e., Co, Cr, Mn, and Sb) showed significantly higher concentrations in weekdays.

Concentrations of trace elements and PCDD/Fs around a municipal solid waste incinerator in Girona (Catalonia, Spain). Human health risks for the population living in the neighborhood

Previously to the modernization of the municipal solid waste incinerator (MSWI) of Campdorà (Girona, Catalonia, Spain) two sampling campaigns (2015 and 2016) were conducted. In each campaign, 8 soil and 4 air samples (PM₁₀ and total particle phase and gas phase) were collected. The levels of As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl and V, and PCDD/Fs were analysed at different distances and wind directions around the MSWI. Environmental levels of trace elements and PCDD/Fs were used to assess exposure and health risks (carcinogenic and non-carcinogenic) for the population living around the facility. In soils, no significant differences were observed for trace elements and PCDD/Fs between both campaigns. In air, significant higher levels of As, Cd, Co, Mn, Ni, Pb, Tl and V were detected in 2016. Regarding soil levels, only Cd (distances) and As, Cu, Mn, and Ni (wind directions) showed significant differences. No differences were noted in the concentrations of trace elements and PCDD/Fs in air levels with respect to distances and directions to the MSWI. No differences were registered in air levels (elements and PCDD/Fs) between points influenced by MSWI emissions and background point. However some differences in congener profile were noted regarding from where back-trajectories come from (HYSPLIT model results), pointing some influence of Barcelona metropolitan area. The concentrations of trace elements and PCDD/Fs were similar -or even lower- than those reported around other MSWIs in Catalonia and various countries. Non-carcinogenic risks were below the safety limit (HQ<1). In turn, carcinogenic risks due to exposure to trace elements and PCDD/Fs were in acceptable ranges, according to national and international standard regulations.

High cancer risks by exposure to PCDD/Fs in the neighborhood of an Integrated Waste Management Facility

In 2014, we conducted a study aimed at screening the concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and various trace elements in air and soil samples collected in an urban area of Sant Adrià de Besòs (Barcelona, Spain) in the vicinity of an Integrated Waste Management Facility (IWMF). It consists of a mechanical-biological treatment plant (MBT) and an old municipal solid waste incinerator (MSWI). Human health risks for the population living in the area were also assessed. The most worrying result was the high cancer risks estimated for the area (2.5×10^-6). In March 2017, we have carried out a new survey to check if the authorities had taken the necessary and urgent measures to reduce the environmental concentrations of PCDD/Fs -and the human health risks- until acceptable levels. Although the concentrations of PCDD/Fs in soils are currently lower (mean value: 1.66 vs. 3.6ng WHO-TEQ/kg in 2014), they are still are notably higher than those found near other MSWIs of Catalonia. In turn, the levels of PCDD/Fs in air are even higher than in 2014 (mean value: 0.044 vs. 0.026pgWHO-TEQ/m³ in 2014), being also the highest detected in similar zones of Catalonia. The current cancer risk due to PCDD/F exposure for the residents in the neighborhood of the IWMF is 2.3×10^-6, a worrying fact as the 10^-6 threshold continues to be exceeded.

Volatile compounds emission and health risk assessment during composting of organic fraction of municipal solid waste

Degradation of mechanically sorted organic fraction (MSOF) of municipal solid waste in composting facilities is among the major contributors of volatile compounds (VCs) generation and emission, causes nuisance problems and health risks on site as well as in the vicinages. The aim of current study was to determine the seasonal (summer and winter) variation and human health risk assessment of VCs in the ambient air of different processing units in MSOF at composting plant in China. Average concentration of VCs was 58.50 and 138.03mg/m³ in summer and winter respectively. Oxygenated compounds were found to be the highest concentration (46.78-91.89mg/m³) with ethyl alcohol as the major specie (43.90-85.31mg/m³) in the two seasons respectively. Nevertheless, individual non-carcinogenic (Hazard relation i.e HR<1) and carcinogenic risk (CR<1.0E-04) of the quantified VCs were within acceptable limit except naphthalene at biofilter unit. In addition, cumulative non-carcinogenic risk exceeded from the threshold limit both in summers and winters in all units except at biofilter unit during winter. Furthermore cumulative carcinogenic risk also exceeded at same unit during the summer season. Therefore special attention should be made to minimize cumulative non-carcinogenic and carcinogenic risk as people are well exposed to mixture of compounds, not to individual.

Volatile Profiles of Emissions from Different Activities Analyzed Using Canister Samplers and Gas Chromatography-Mass Spectrometry (GC/MS) Analysis: A Case Study

The objective of present study was to identify volatile organic compounds (VOCs) emitted from several sources (fuels, traffic, landfills, coffee roasting, a street-food laboratory, building work, indoor use of incense and candles, a dental laboratory, etc.) located in Palermo (Italy) by using canister autosamplers and gas chromatography-mass spectrometry (GC-MS) technique. In this study, 181 VOCs were monitored. In the atmosphere of Palermo city, propane, butane, isopentane, methyl pentane, hexane, benzene, toluene, meta- and para-xylene, 1,2,4 trimethyl benzene, 1,3,5 trimethyl benzene, ethylbenzene, 4 ethyl toluene and heptane were identified and quantified in all sampling sites.

Dispersion modeling and health risk assessment of VOCs emissions from municipal solid waste transfer station in Tehran, Iran

BACKGROUND

The waste transfer stations (WTSs) is one of the most important factors affecting on environment and human health. This research is aimed to evaluate health risk of VOCs among WTS personnel and provide a model for dispersion of VOCs. The Air Pollution Model (TAPM) is able to simulate WTS emissions dispersion over each town.

RESULT

GC-MS was used to analysis collected gas samples to detect and estimate carcinogenic and non-carcinogenic VOCs health risks. The total lifetime cancer risk values for the all personnel (3.30E-05), was more than acceptable limit (1.00E-06). Furthermore, hazard ratio (HR) of 1,2,3-trimethylbenzene, 1,3-dichloropropane, toluene, m,p-xylene and ethylbenzene were 3.7, 1.9 E-01, 4.4 E-03, 5.5 E-02 and 1.5 E-03, respectively, and total HR of the mentioned compounds were more than accepted limit (HR < 1.00). IOA is 0.85 and RMSE is 2.16 and TAPM has a good performance. The VOCs level is considerable in 1600 m far from the WTS particularly in summer that require more attention.

CONCLUSION

The exposure to VOCs was at a high level in WTS, and some controlling strategy should be used for decreasing the pollution and protecting the citizens and personnel against non-cancerous and cancerous risks.

Statistical modeling of O3, NOx, CO, PM2.5, VOCs and noise levels in commercial complex and associated health risk assessment in an academic institution

Indoor Air Quality (IAQ) is considered to be of great concern due to its adverse impact on the human health nowadays. The presence of different air pollutants along with noise may aggravate the IAQ. The present study attempts to examine IAQ in terms of major criteria air pollutants (O₃, NOx=NO+NO₂, CO and PM_2.5) along with total volatile organic compound (TVOC), individual VOC and noise pollution in indoor and outdoor environment of a Commercial Shopping Complex (CSC) in Delhi. Real time measurements have been carried out for O₃, NOx, CO, PM_2.5, TVOC and noise while thirteen individual VOCs have been estimated using NIOSH method was performed using Gas Chromatograph. The study also aimed to find out the relationship among VOCs, source estimation using Principal Component Analysis. The observed results for the targeted pollutants were also compared with international and national recommended permissible values. The mean values of O₃, NOx, CO, PM_2.5 and TVOC are found to be 17.6/(15.0) ppb, 15.8/(14.1) ppb, 8.4/(1.9) ppm, 125.4/(74.6) μg/m³ and 412.5/(226.5) μg/m³ for indoor/(outdoor), respectively. Among the individual VOC, toluene was the most abundant followed by xylene-isomers and benzene. The noise pollution level in Indoor/outdoor were found to be 51.5/46.4dB which is below the guideline value (65dB) provided by the WHO. Most of the pollutants were found to have indoor sources. The different kinds of pollutants and noise may have synergistic effect and aggravate the health of the people working and visiting the CSC.

The relationship between solvent use and BTEX concentrations in occupational environments

Indoor air quality is an increasing concern; it causes significant damage to health because it is recycled in confined environments for extended periods of time. Among the pollutants found in these environments, benzene, toluene, ethylbenzene, and xylenes (BTEX) are known for their potential toxic, mutagenic, and carcinogenic effects. This study monitored the BTEX concentrations in paint, carpentry, and varnish workplaces and evaluated the potential to cause adverse health effects on workers in these environments. Twenty samples were collected in workplaces, 20 samples were collected outside the area, and eight samples were taken of the products used. Samples were collected using coconut shell cartridges, and chemical analyses were performed by gas chromatography with mass spectrometry. Toluene presented higher indoor concentrations and indoor and outdoor ratios, indicating that the paint and varnish workplaces had significant BTEX sources. The highest benzene and toluene concentrations were obtained from the paint workshop, and higher concentrations of ethylbenzene and xylenes were obtained in the varnish workshop. The highest non-carcinogenic risks were obtained for m + p-xylenes in the varnish work place, and the second highest non-carcinogenic risk was also determined for the same workshop.

Predicting Aspergillus fumigatus exposure from composting facilities using a dispersion model: A conditional calibration and validation

Bioaerosols are released in elevated quantities from composting facilities and are associated with negative health effects, although dose-response relationships are unclear. Exposure levels are difficult to quantify as established sampling methods are costly, time-consuming and current data provide limited temporal and spatial information. Confidence in dispersion model outputs in this context would be advantageous to provide a more detailed exposure assessment. We present the calibration and validation of a recognised atmospheric dispersion model (ADMS) for bioaerosol exposure assessments. The model was calibrated by a trial and error optimisation of observed Aspergillus fumigatus concentrations at different locations around a composting site. Validation was performed using a second dataset of measured concentrations for a different site. The best fit between modelled and measured data was achieved when emissions were represented as a single area source, with a temperature of 29°C. Predicted bioaerosol concentrations were within an order of magnitude of measured values (1000-10,000CFU/m³) at the validation site, once minor adjustments were made to reflect local differences between the sites (r²>0.7 at 150, 300, 500 and 600m downwind of source). Results suggest that calibrated dispersion modelling can be applied to make reasonable predictions of bioaerosol exposures at multiple sites and may be used to inform site regulation and operational management.

Human health risks of formaldehyde indoor levels: An issue of concern

Formaldehyde is a carcinogenic substance for humans. Exposure to formaldehyde may also cause eye and respiratory tract irritation, as well as skin sensitization. The main indoor sources of formaldehyde are wood-pressed products, insulation materials, paints, varnishes, household cleaning products and cigarettes, among others. Although this chemical is a well-known indoor pollutant, data on indoor concentrations of formaldehyde are still scarce in some countries. In February 2014, 10 homes in Catalonia, Spain, were randomly selected to collect indoor (bedroom and living room) and outdoor air samples. Ten additional samples were also collected at different workplaces (e.g., offices, shops, classrooms, etc.). Formaldehyde air levels found in homes ranged from 10.7 to 47.7 μg m(-3), from 9.65 to 37.2 μg m(-3), and from 0.96 to 3.37 μg m(-3) in bedrooms, living rooms, and outdoors, respectively. Meanwhile, at workplaces, indoor air levels ranged from 5.86 to 40.4 μg m(-3). These levels are in agreement with data found in the scientific literature. Non-carcinogenic risks were above the threshold limit (HQ > 1), and carcinogenic risks were not acceptable either (>10(-4)). Despite the current study limitations, the results confirm that formaldehyde indoor levels are a matter of health concern, which must be taken into account by policymakers and regulatory bodies.

Health risks for the population living in the vicinity of an Integrated Waste Management Facility: screening environmental pollutants

We performed a screening investigation to assess the human health risks of the Integrated Waste Management Facility (IWMF: mechanical-biological treatment (MBT) plant plus municipal solid waste incinerator (MSWI); Ecoparc-3) of Barcelona (Spain). Air concentrations of pollutants potentially released by the MBT plant (VOCs and bioaerosols) and the MSWI (trace elements, PCDD/Fs and PCBs) were determined. Trace elements, PCDD/Fs and PCBs were also analyzed in soil samples. The concentrations of trace elements and bioaerosols were similar to those previously reported in other areas of similar characteristics, while formaldehyde was the predominant VOC. Interestingly, PCDD/F concentrations in soil and air were the highest ever reported near a MSWI in Catalonia, being maximum concentrations 10.8 ng WHO-TEQ/kg and 41.3 fg WHO-TEQ/m(3), respectively. In addition, there has not been any reduction in soils, even after the closure of a power plant located adjacently. Human health risks of PCDD/F exposure in the closest urban nucleus located downwind the MSWI are up to 10-times higher than those nearby other MSWIs in Catalonia. Although results must be considered as very preliminary, they are a serious warning for local authorities. We strongly recommend to conduct additional studies to confirm these findings and, if necessary, to implement measures to urgently mitigate the impact of the MSWI on the surrounding environment. We must also state the tremendous importance of an individual evaluation of MSWIs, rather than generalizing their environmental and health risks.

Fungal burden in waste industry: an occupational risk to be solved

High loads of fungi have been reported in different types of waste management plants. This study intends to assess fungal contamination in one waste-sorting plant before and after cleaning procedures in order to analyze their effectiveness. Air samples of 50 L were collected through an impaction method, while surface samples, taken at the same time, were collected by the swabbing method and subject to further macro- and microscopic observations. In addition, we collected air samples of 250 L using the impinger Coriolis μ air sampler (Bertin Technologies) at 300 L/min airflow rate in order to perform real-time quantitative PCR (qPCR) amplification of genes from specific fungal species, namely Aspergillus fumigatus and Aspergillus flavus complexes, as well as Stachybotrys chartarum species. Fungal quantification in the air ranged from 180 to 5,280 CFU m(-3) before cleaning and from 220 to 2,460 CFU m(-3) after cleaning procedures. Surfaces presented results that ranged from 29×10(4) to 109×10(4) CFU m(-2) before cleaning and from 11×10(4) to 89×10(4) CFU m(-2) after cleaning. Statistically significant differences regarding fungal load were not detected between before and after cleaning procedures. Toxigenic strains from A. flavus complex and S. chartarum were not detected by qPCR. Conversely, the A. fumigatus species was successfully detected by qPCR and interestingly it was amplified in two samples where no detection by conventional methods was observed. Overall, these results reveal the inefficacy of the cleaning procedures and that it is important to determine fungal burden in order to carry out risk assessment.

Exposures and health outcomes in relation to bioaerosol emissions from composting facilities: a systematic review of occupational and community studies

The number of composting sites in Europe is rapidly increasing, due to efforts to reduce the fraction of waste destined for landfill, but evidence on possible health impacts is limited. This article systematically reviews studies related to bioaerosol exposures within and near composting facilities and associated health effects in both community and occupational health settings. Six electronic databases and bibliographies from January 1960 to July 2014 were searched for studies reporting on health outcomes and/or bioaerosol emissions related to composting sites. Risk of bias was assessed using a customized score. Five hundred and thirty-six papers were identified and reviewed, and 66 articles met the inclusion criteria (48 exposure studies, 9 health studies, 9 health and exposure studies). Exposure information was limited, with most measurements taken in occupational settings and for limited time periods. Bioaerosol concentrations were highest on-site during agitation activities (turning, shredding, and screening). Six studies detected concentrations of either Aspergillus fumigatus or total bacteria above the English Environment Agency's recommended threshold levels beyond 250 m from the site. Occupational studies of compost workers suggested elevated risks of respiratory illnesses with higher bioaerosol exposures. Elevated airway irritation was reported in residents near composting sites, but this may have been affected by reporting bias. The evidence base on health effects of bioaerosol emissions from composting facilities is still limited, although there is sufficient evidence to support a precautionary approach for regulatory purposes. While data to date are suggestive of possible respiratory effects, further study is needed to confirm this and to explore other health outcomes.

Determination of volatile organic compounds and associated health risk assessment in residential homes and hostels within an academic institute, New Delhi

The purpose of this study was to investigate the concentrations of volatile organic compounds (VOCs) in different indoor microenvironments of residential homes and hostels in an academic institute, in New Delhi, during March-May 2011. Eleven VOCs (aromatic and halogenated) were assessed. Sampling and analytical procedure were based on National Institute for Occupational Safety and Health (NIOSH) standard method. The lifetime cancer and non-cancer risk were calculated for targeted VOCs using US Environmental Protection Agency guidelines. The mean concentrations of ∑ VOCs (sum of monitored VOCs) and individual VOC were found to be higher indoors as compared to outdoors at both types of premises. Indoor to outdoor (I/O) ratios of the targeted VOCs exceeded 1.0, suggesting the significant presence of indoor sources. Strong correlations between I/O concentrations of VOCs in the current study suggest the presence of common sources. Factor analysis (FA) was used for source evaluation separately at two premise types. The estimated lifetime cancer risks in the current study for all occupants at both premises exceeded 10(-6) .

Formaldehyde: a chemical of concern in the vicinity of MBT plants of municipal solid waste

The mechanical-biological treatment (MBT) of municipal solid waste (MSW) has a number of advantages in comparison to other MSW management possibilities. However, adverse health effects related to this practice are not well known yet, as a varied typology of microbiological and chemical agents may be generated and released. In 2010, we initiated an environmental monitoring program to control air levels of volatile organic compounds (VOCs) and microbiological pollutants near an MBT plant in Montcada i Reixac (Catalonia, Spain). In order to assess any temporal and seasonal trends, four 6-monthly campaigns were performed. Important fluctuations were observed in the levels of different biological indicators (total and Gram-negative bacteria, fungi grown at 25 °C and 37 °C, and more specifically, Aspergillus fumigatus). Although overall bioaerosols concentrations were rather low, a certain increase in the mean values of bacteria and fungi was observed in summer. In contrast, higher concentrations of VOCs were found in winter, with the only exception of formaldehyde. Interestingly, although this compound was not detected in one of the sampling campaigns, current airborne levels of formaldehyde were higher than those previously reported in urban areas across Europe. Furthermore, the non-carcinogenic risks (Hazard Quotient), particularly in winter, as well as the cancer risks associated with the inhalation of VOCs, exceeded the threshold values (1 and 10(-5), respectively), reaffirming the need of continuing with the monitoring program, with special emphasis on formaldehyde, a carcinogenic/mutagenic substance.

Dissociative photoionization of β-pinene: an experimental and theoretical study

We investigated the photoionization and dissociation photoionization of the β-pinene molecular using time-of-flight mass spectrometry with a tunable vacuum ultraviolet source in the region from 8.00eV to 15.50eV. The experimental ionization energy (IE) value is 8.60eV using electron impact as the ionization source which is not in good agreement with theoretical value (8.41 eV) with a G3MP2 method. We obtained the accurate IE of β-pinene (8.45 ± 0.03eV) derived from the efficiency spectrum which is in good agreement with the theoretical value (8.38eV) of the CBS-QB3 method. We elucidated the dissociation pathways of primary fragment ions from the β-pinene cation on the basis of experimental observations in combination with theoretical calculations. Most of the dissociation pathways occur via a rearrangement reaction prior to dissociation. We also determined the structures of the transition states and intermediates for those isomerization processes.

Assessment of fungal contamination in waste sorting and incineration-case study in Portugal

Organic waste is a rich substrate for microbial growth, and because of that, workers from waste industry are at higher risk of exposure to bioaerosols. This study aimed to assess fungal contamination in two plants handling solid waste management. Air samples from the two plants were collected through an impaction method. Surface samples were also collected by swabbing surfaces of the same indoor sites. All collected samples were incubated at 27°C for 5 to 7 d. After lab processing and incubation of collected samples, quantitative and qualitative results were obtained with identification of the isolated fungal species. Air samples were also subjected to molecular methods by real-time polymerase chain reaction (RT PCR) using an impinger method to measure DNA of Aspergillus flavus complex and Stachybotrys chartarum. Assessment of particulate matter (PM) was also conducted with portable direct-reading equipment. Particles concentration measurement was performed at five different sizes (PM0.5; PM1; PM2.5; PM5; PM10). With respect to the waste sorting plant, three species more frequently isolated in air and surfaces were A. niger (73.9%; 66.1%), A. fumigatus (16%; 13.8%), and A. flavus (8.7%; 14.2%). In the incineration plant, the most prevalent species detected in air samples were Penicillium sp. (62.9%), A. fumigatus (18%), and A. flavus (6%), while the most frequently isolated in surface samples were Penicillium sp. (57.5%), A. fumigatus (22.3%) and A. niger (12.8%). Stachybotrys chartarum and other toxinogenic strains from A. flavus complex were not detected. The most common PM sizes obtained were the PM10 and PM5 (inhalable fraction). Since waste is the main internal fungal source in the analyzed settings, preventive and protective measures need to be maintained to avoid worker exposure to fungi and their metabolites.

Pollution profiles, health risk of VOCs and biohazards emitted from municipal solid waste transfer station and elimination by an integrated biological-photocatalytic flow system: a pilot-scale investigation

Volatile organic compounds (VOCs) and biohazards air pollution in municipal solid waste transfer station were investigated. As compressor working, the concentrations of almost all quantified 14 VOCs (0.32-306.03 μg m(-3)) were much higher than those as compressor off (0-13.31 μg m(-3)). Comparatively, only 3 VOCs with extremely low concentrations could be detected at control area. Total microorganism was 7567 CFU m(-3) as compressor working, which was 1.14 and 6.22 times higher than that of compressor off and control area, respectively. Bacteria were the most abundant microorganism at all three sampling places. At pilot-scale, during whole 60-day treatment, for VOCs, the average removal efficiencies were over 92% after biotrickling filter-photocatalytic (BTF-PC) treatment. Although non-cancer and cancer risks of some VOCs were over the concern level before treatment, almost all VOCs were removed substantially and both potential risks were below the concern after BTF-PC treatment. Additionally, biohazard concentrations decreased dramatically and air quality was purified from polluted to cleanness after PC treatment. All results demonstrated that the integrated technology possessed high removal capacity and long stability for the removal of VOCs and biohazards at a pilot scale.

Occupational hygiene in terms of volatile organic compounds (VOCs) and bioaerosols at two solid waste management plants in Finland

Factors affecting occupational hygiene were measured at the solid waste transferring plant at Hyvinkää and at the optic separation plant in Hämeenlinna. Measurements consisted of volatile organic compounds (VOCs) and bioaerosols including microbes, dust and endotoxins. The most abundant compounds in both of the plants were aliphatic and aromatic hydrocarbons, esters of carboxylic acids, ketones and terpenes. In terms of odour generation, the most important emissions were acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene due to their low threshold odour concentrations. At the optic waste separation plant, limonene occurred at the highest concentration of all single compounds of identified VOCs. The concentration of any single volatile organic compound did not exceed the occupational exposure limit (OEL) concentration. However, 2,3-butanedione as a health risk compound is discussed based on recent scientific findings linking it to lung disease. Microbe and dust concentrations were low at the waste transferring plant. Only endotoxin concentrations may cause health problems; the average concentration inside the plant was 425 EU/m(3) which clearly exceeded the threshold value of 90 EU/m(3). In the wheel loader cabin the endotoxin concentrations were below 1 EU/m(3). High microbial and endotoxin concentrations were measured in the processing hall at the optic waste separation plant. The average concentration of endotoxins was found to be 10,980 EU/m(3), a concentration which may cause health risks. Concentrations of viable fungi were quite high in few measurements in the control room. The most problematic factor was endotoxins whose average measured concentrations was 4853 EU/m(3).

Use of thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) on identification of odorant emission focus by volatile organic compounds characterisation

Volatile organic compounds (VOCs) from several different municipal solid wastes' treatment plants in Mallorca (Spain) have been analysed by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Ambient (immission) air was collected during February and March 2011 by active sampling onto sorbents Tenax™ TA and Carboxen™ 1000. The study presents the chemical characterisation of 93 volatile organic compounds (VOCs) from an overall set of 84 immission air samples. 70 VOCs were positively identified. The linear fit for all 93 external standard calibration, from 10 mg L(-1) to 150 mg L(-1) (n=4), was within the range 0.974<r(2)<0.998. Limits of detection of the method (LOD) for all the standards were within the range 1.1-4,213 pg, as the absolute standard amount spiked into sorbent tubes in 1 μL standard mixture (dissolved in methanol). Overall results stated systematic correlation between waste's nature and VOCs' air composition. Organic wastes show main contribution of terpenes, waste water sludge residues' of reduced sulphured compounds (RSCs) and municipal solid wastes show contribution of a wide sort of VOCs. The use of a chemometric approach for variable's reduction to 12 principal components enables evaluation of similarities and dissimilarities between facilities. PCA clearly related samples to its corresponding facility on the basis of their VOCs composition and the ambient temperature.