Passive Air Sampling Technique Research Articles

Microbiological characteristics of indoor air bioaerosols in a waste paper recycling factory

There has been an increasing interest among occupational hygienists and public health officials in indoor air quality assessment in industrial workplace environments. Exposure to bioaerosols may pose health risks to workers operating in the processing of recycled waste paper. This study was conducted in two waste paper recycling factories. Air sampling of the factory was performed on weekly basis over a period of 3 months employing passive air sampling technique (the settle plates) with standard Petri dishes in which appropriate culture media are used for counting bacteria and fungi in air samples. In addition, metagenome analyses were conducted to obtain more details about the diversity and abundance of bacteria in the investigated factory. Results showed abundant bacterial and fungal counts in the waste paper factory in all the manufacturing stages. In particular, the cutting/shredding unit exhibited high microbiological contamination; thus, corrective measures should be taken in order to achieve better indoor air quality. The most dominant genus detected according to both DGGE sequencing and metagenome analysis was Thermicanus. The dominance of this thermophilic, microaerophilic fermentative species especially during summer season reflects the condition within the factory as well as the source of the recycled paper and the way it has been handled and stored. An air flow ventilation system that prevents contamination from areas where raw waste paper is handled is recommended.

Assessment of Indoor Microbial Quality of Library’s Premise: Case of Central Library of the University of Yaoundé I

Background: Good indoor air quality is important for human health and comfort, because people spend a most of their time within buildings. Microbial pollution is a key element of indoor air pollution. Bacteria and fungi growing indoors when sufficient moisture is available usually cause indoor air pollution. Methods: This study was conducted to assess the microbial concentration and to identify the main bacteria and fungi in the indoor environment of Central Library of the University of Yaounde I. A total of 76 samples were taken from indoor air, surfaces and mouldy books. Bioaerosol sampling and air concentration were made by passive air sampling technique using petri dishes containing different culture media and exposed for 30, 60 and 90 min in the morning and afternoon. Sampling of surfaces and mouldy books were made by rubbing using sterile swab. The identification of the isolated microorganisms was based on macroscopic, microscopic and biochemical characters. Results: The concentrations of bacteria and fungi in the indoor environment of Central Library of the University of Yaounde I ranged between 747 and 2324 CFU/m for the air and 40 and 500 CFU/cm2 for surfaces. In the examined area, the predominant culturable species of microflora were members of the following bacteria genera; Bacillus spp, Staphylococcus spp, Micrococcus spp, Pseudomonas spp, Rhodococcus spp, Enterobacter spp, Klebsiella spp and Escherichia spp and fungi; Aspergillus spp, Penicillium spp, Curvularia spp, Mucor spp, Cladosporium spp, Candida spp Rhodotorula spp, Fusarium spp, Trichophyton spp, Acremonium spp, Aureobasidium spp, Rhizopus spp and Chrysonilia spp. Conclusion: High concentrations of bacteria and fungi were observed in the central library of the University of Yaounde I. Precautions and safety measures should be taken to reduce microbial pollution at universities libraries by improving libraries ventilation and disinfection.

Microbiological Assessment of Indoor Air of Takalar County Hospital Wards in South Sulawesi, Indonesia

Poor indoor air quality may lead to hospital acquired infection. Microbiological parameter is one of main standards of indoor air quality. The study objective was to investigate microbiological assessment of indoor air of different wards of Takalar County Hospital, South Sulawesi, Indonesia. Four wards were used for sample collection and these included third, second, first and VIP class ward. Room air temperature, humidity, lighting and number of visitor were also observed. Passive air sampling technique using open Petri dishes containing different culture media was employed. Blood agar plate was used for the bacteria, while Sabouraud dextrose agar plates were used for the fungi. Samplings were done twice daily, one in the morning and other in the afternoon. Isolates were identified according to standard methods. Results show that there was second class ward recorded the highest bacterial growth (1,413 cfu/m³ in the afternoon). The bacteria isolates were Bacillus sp, Enterobacter sp, <i>Staphylococcus aureus</i>, and <i>Staphylococcus epidermidis. Staphylococcus aureus</i> was the predominantly isolated bacterium. For the conclusion, from the reduction noticed in the morning samples, stringent measures such as proper disinfection and regular cleaning, restriction of patient relatives’ movement in and out the wards need to be enforced so as to improve the quality of indoor air of hospital wards.

Evaluating spatial distribution and seasonal variation of phthalates using passive air sampling in southern India

Usage of phthalates as plasticizers has resulted in worldwide occurrence and is becoming a serious concern to human health and environment. However, studies on phthalates in Indian atmosphere are lacking. Therefore, we studied the spatio-temporal trends of six major phthalates in Tamil Nadu, southern India, using passive air samplers. Phthalates were ubiquitously detected in all the samples and the average total phthalates found in decreasing order is pre-monsoon (61 ng m−3) > summer (52 ng m−3) > monsoon (17 ng m−3). Largely used phthalates, dibutylphthalate (DBP) and diethylhexlphthalate (DEHP) were predominantly found in all the seasons with contribution of 11–31% and 59–68%, respectively. The highest total phthalates was observed in summer at an urban location (836 ng m−3). Furthermore, through principal component analysis, potential sources were identified as emissions from additives of plasticizers in the polymer industry and the productions of adhesives, building materials and vinyl flooring. Although inhalation exposure of infants was higher than other population segments (toddlers, children and adults), exposure levels were found to be safe for people belonging to all ages based on reference dose (RfD) and tolerable daily intake (TDI) values. This study first attempted to report seasonal trend based on atmospheric monitoring using passive air sampling technique and exposure risk together.

High bacterial load of indoor air in hospital wards: the case of University of Gondar teaching hospital, Northwest Ethiopia

Background: The air inhaled by people is abundantly populated with microorganisms which also are called bioaerosols. Bioaerosols is a colloidal suspension, formed by liquid droplets and particles of solid matter in the air, whose components contain or have attached to them viruses, fungal spores and conidia, bacterial endospores, plant pollen and fragments of plant tissues. They account for 5–34 % of indoor air pollution. Methods: A cross-sectional study was conducted to assess the bacteriological concentration and to identify specific species of bacteria in the indoor air of Gondar University teaching hospital. Air samples were taken from 14 randomly selected wards. Bacterial measurements were made by passive air sampling technique i.e., the settle plate method. In each ward five Petri dishes were exposed for 30 and 60 min in the morning and afternoon. Bacteria were collected on nutrient agar and blood agar media. Both quantitative and qualitative analyses were conducted. The quantitative analysis was mainly conducted to determine bacterial load or number of bacteria in the indoor air. Bacterial load was enumerated as colony forming units. Qualitative analysis was conducted to identify specific species of bacteria. For this study we have selected Staphylococcus aureus and Streptococcus which had high public health concern. Mannitol test was used to isolate Staphylococcus aureus, whereas Bacitracin test was conducted to isolate Streptococcus pyogene. Result: The result of this study indicated that the highest bacterial load which was 1468 CFU/m3 has been recorded at 2:00 PM in Ward C at 60 min exposure time and the lowest bacterial concentration (i.e., 480 CFU/m3) was recorded at 8:00 AM in physiotherapy ward. Based on the result bacterial concentration of indoor air of Gondar University teaching hospital was found between 480 and 1468 CFU/m3. The result of one way ANOVA showed that the highest mean bacterial concentration (1271.00 CFU/m3) was found in Medical ward and the least (583.25 CFU/m3) concentration was found in ward D and the grand total average concentration was 878.43 CFU/m3. Favorable conditions for growth and multiplication of bacteria like temperature (26.5–29.5 °C), humidity (64.5–85 %), presence of unhygienic attached toilets, poor waste management system and poor ventilation system were observed during the survey. Staphylococcus aureus was identified in 10 wards and Streptococcus pyogenes was isolated in 8 hospital wards. Conclusions: Compared with different indoor air biological standards, higher concentration of indoor air bacterial load was found in Gondar University teaching hospital. The higher bacterial load may be due to temperature, humidity, presence of unhygienic attached toilets, poor waste management system and poor ventilation system. Therefore, attention must be given to control those environmental factors which favor the growth and multiplication of microbes in indoor environment. In addition, also the ventilation condition, cleanliness of toilets, sweeping methods and waste disposal system of the compound should be improved.

High bacterial load of indoor air in hospital wards: the case of University of Gondar teaching hospital, Northwest Ethiopia.

BackgroundThe air inhaled by people is abundantly populated with microorganisms which also are called bioaerosols. Bioaerosols is a colloidal suspension, formed by liquid droplets and particles of solid matter in the air, whose components contain or have attached to them viruses, fungal spores and conidia, bacterial endospores, plant pollen and fragments of plant tissues. They account for 5–34 % of indoor air pollution.MethodsA cross-sectional study was conducted to assess the bacteriological concentration and to identify specific species of bacteria in the indoor air of Gondar University teaching hospital. Air samples were taken from 14 randomly selected wards. Bacterial measurements were made by passive air sampling technique i.e., the settle plate method. In each ward five Petri dishes were exposed for 30 and 60 min in the morning and afternoon. Bacteria were collected on nutrient agar and blood agar media. Both quantitative and qualitative analyses were conducted. The quantitative analysis was mainly conducted to determine bacterial load or number of bacteria in the indoor air. Bacterial load was enumerated as colony forming units. Qualitative analysis was conducted to identify specific species of bacteria. For this study we have selected Staphylococcus aureus and Streptococcus which had high public health concern. Mannitol test was used to isolate Staphylococcus aureus, whereas Bacitracin test was conducted to isolate Streptococcus pyogene.ResultThe result of this study indicated that the highest bacterial load which was 1468 CFU/m3 has been recorded at 2:00 PM in Ward C at 60 min exposure time and the lowest bacterial concentration (i.e., 480 CFU/m3) was recorded at 8:00 AM in physiotherapy ward. Based on the result bacterial concentration of indoor air of Gondar University teaching hospital was found between 480 and 1468 CFU/m3. The result of one way ANOVA showed that the highest mean bacterial concentration (1271.00 CFU/m3) was found in Medical ward and the least (583.25 CFU/m3) concentration was found in ward D and the grand total average concentration was 878.43 CFU/m3. Favorable conditions for growth and multiplication of bacteria like temperature (26.5–29.5 °C), humidity (64.5–85 %), presence of unhygienic attached toilets, poor waste management system and poor ventilation system were observed during the survey. Staphylococcus aureus was identified in 10 wards and Streptococcus pyogenes was isolated in 8 hospital wards.ConclusionsCompared with different indoor air biological standards, higher concentration of indoor air bacterial load was found in Gondar University teaching hospital. The higher bacterial load may be due to temperature, humidity, presence of unhygienic attached toilets, poor waste management system and poor ventilation system. Therefore, attention must be given to control those environmental factors which favor the growth and multiplication of microbes in indoor environment. In addition, also the ventilation condition, cleanliness of toilets, sweeping methods and waste disposal system of the compound should be improved.

Reducing bacterial contamination in an Orthopedic Theatre ventilated by natural ventilation, in a Developing Country.

All surgical procedures have the potential for infection and some of the main sources are contamination from airborne particles, theatre personnel and the theatre environment. There is strong evidence that the use of ultra-clean air flow systems in orthopedic operating theatres reduces the incidence of deep sepsis after surgery. In the developing world however, this is often an unrealistic solution. The aim of this study was to establish baseline levels of contamination in a working orthopedic theatre, at the Queen Elizabeth Central Hospital, Blantyre, Malawi. To feedback results to the theatre team, promote infection prevention discussion and work with the team to implement workable and realistic goals to improve the intra-operative environment. Samples were collected from theatre equipment available at the time of surgery, from theatre water and theatre air using passive air sampling techniques. Samples were immediately transferred to the Central Microbiology Laboratory for culture on basic culture media. Bacterial contamination of theatre equipment, intra-operative theatre air and water was detected. Results were discussed with the theatre and infection prevention team who were receptive to feedback with regards to infection prevention strategies and keen to develop simple measures which could be put in place to change practice. In this setting, we suggest that implementing workable and realistic goals such as, establishing baseline rates of bacterial contamination and introduction of strict protocols for asepsis and theatre etiquette, may reduce bacterial contamination rates and subsequent intra-operative infection in the absence of expensive engineering solutions.

Quantitative Assessment of Bio-Aerosols Contamination in Indoor Air of University Dormitory Rooms

The purpose of this study is to provide insight into how students are exposed to indoor bio-aerosols in the dormitory rooms and to figure out the major possible factors that govern the contamination levels. The Bio-aerosols concentration level of indoor air of thirty dormitory rooms of Jimma University was determined by taking 120 samples. Passive air sampling technique; the settle plate method using open Petri-dishes containing different culture media was employed to collect sample twice daily. The range of bio-aerosols contamination detected in the dormitory rooms was 511-9960 CFU/m(3) for bacterial and 531-6568 CFU/m(3) for fungi. Based on the criteria stated by WHO expert group, from the total 120 samples 95 of the samples were above the recommended level. The statistical analysis showed that, occupancy were significantly affected the concentrations of bacteria that were measured in all dormitory rooms at 6:00 am sampling time (p-value=0.000) and also the concentrations of bacteria that were measured in all dormitory rooms were significantly different to each other (p-value=0.013) as of their significance difference in occupancy (p-value=0.000). Moreover, there were a significant different on the contamination level of bacteria at 6:00 am and 7:00 pm sampling time (p=0.015), whereas there is no significant difference for fungi contamination level for two sampling times (p= 0.674). There is excessive bio-aerosols contaminant in indoor air of dormitory rooms of Jimma University and human occupancy produces a marked concentration increase of bacterial contamination levels and most fungi species present into the rooms air of Jimma University dormitory were not human-borne.

Microbiological Assessment of Indoor Air of Teaching Hospital Wards: A case of Jimma University Specialized Hospital.

Hospital environment represents a congenial situation where microorganisms and susceptible patients are indoors together. Thus, the objective of this study is to provide fundamental data related to the microbial quality of indoor air of Jimma University Specialized Hospital wards, to estimate the health hazard and to create standards for indoor air quality control. The microbial quality of indoor air of seven wards of Jimma University Specialized Hospital was determined. Passive air sampling technique, using open Petri-dishes containing different culture media, was employed to collect sample twice daily. The concentrations of bacteria and fungi aerosols in the indoor environment of the wards ranged between 2123 - 9733 CFU/m(3). The statistical analysis showed that the concentrations of bacteria that were measured in all studied wards were significantly different from each other (p-value=0.017), whereas the concentrations of fungi that were measured in all sampled wards were not significantly different from each other (p-value=0.850). Moreover, the concentrations of bacteria that were measured at different sampling time (morning and afternoon) were significantly different (p-value =0.001). All wards that were included in the study were heavily contaminated with bacteria and fungi. Thus, immediate interventions are needed to control those environmental factors which favor the growth and multiplication of microbes, and it is vital to control visitors and students in and out the wards. Moreover, it is advisable that strict measures be put in place to check the increasing microbial load in the hospital environment.

GIS-assisted dispersion of SO2 in the industrial regions.

Sulfur dioxide is one of the most important pollutants in urban areas which cause respiratory problems and acid rain. The aim of this research is to study the feasibility of using passive diffusive air sampling and GIS technique to determine the dispersion level of SO2 in the industrialized Zarghan area and assessing the contribution level of generating sources of SO2 in the urban areas. It is also essential to determine the contribution of other sources and dispersion radius of pollutants in the area as well. In this study, we used passive sampling method to measure the concentration of sulfur dioxide at 10 monitoring stations. Interpolation tools in ArcGIS technique create a continuous surface from measured values to predict SO2 concentration in other parts of the city. The concentrations of SO2 around Shiraz oil refinery and Dudej region located at 3 km from the oil refinery were 60 and 19 μg m(-3), respectively. In conclusion the results indicated that SO2 concentration was not exceeded the standard limit in the residential area and the role of the local highway and industrial park was not significant.

Organochlorine pesticides in air and soil and estimated air–soil exchange in Punjab, Pakistan

This study provides the first systematic data on the distribution of organochlorine pesticides (OCPs) in the soils and atmosphere of the Punjab province, Pakistan. Atmospheric concentrations of OCPs were estimated by using the polyurethane foam passive air sampling (PUF-PAS) technique. DDTs (dichlorodiphenyltrichloroethane), HCHs (hexachlorocyclohexane) and chlordane were the dominant OCPs found in both soil and air samples. The average concentrations of DDTs, HCHs and chlordane were 350, 55 and 99pgm−3 in air and 40, 7.8 and 3.8ngg−1 in soils, respectively. Air–soil exchange of OCPs was estimated by calculating the fugacities in soil and air. Fugacity fraction (ff) values indicate that soils are acting as a secondary source to contaminate the atmosphere at certain sampling stations.

Development of a Passive Sampling Device Using Polyurethane Foam (PUF) to Measure Polychlorinated Biphenyls (PCBs) and Organochlorine Pesticides (OCPs) near Landfills

Recently passive air sampling techniques have been extensively studied and employed in the environmental monitoring of semi volatile chemicals. Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) samples were collected for 4-week intervals throughout one year from a landfill in Bursa, Turkey. In this study, a passive air sampler (PAS) was designed using polyurethane foam (PUF). The differences between PAS employed in this study and in literature are their shape and ventilation approach. Ventilation pipes, located on top and bottom of the sampler, were employed to prevent precipitation and particles from entering inside the sampler. The sampling rates (R) for PUF was calculated as 7.3 m3/d for PCBs and as 3.9 m3/d for OCPs. The determined average concentrations were 311 ± 178 pg/m3 for PCBs, 198 ± 210 pg/m3 for OCPs.

Testing a passive method for measurement of surface ozone concentrations (Mondy Station, East Siberia)

The efficiency a new passive air sampling technique has been studied as a universal low-cost means of surface ozone monitoring. As a result of a half-year observation cycle, a large array of experimental data on surface ozone concentrations was collected using two techniques, i.e., the passive sampling and the optical technique. The efficiency of suggested passive ozone sampling technique is confirmed for long-term back-country measurements, particularly, for ROSHYDROMET stations.

Observations on persistent organic pollutants in indoor and outdoor air using passive polyurethane foam samplers

Air quality data of persistent organic pollutants (POPs) indoors and outdoors are sparse or lacking in several parts of the world, often hampered by the cost and inconvenience of active sampling techniques. Cheap and easy passive air sampling techniques are therefore helpful for reconnaissance surveys. As a part of the Megacity Initiative: Local and Global Research Observations (MILAGRO) project in Mexico City Metropolitan Area in 2006, a range of POPs (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs)) were analyzed in polyurethane foam (PUF) disks used as passive samplers in indoor and outdoor air. Results were compared to those from samplers deployed simultaneously in Gothenburg (Sweden) and Lancaster (United Kingdom). Using sampling rates suggested in the literature, the sums of 13 PAHs in the different sites were estimated to be 6.1–180 ng m −3, with phenanthrene as the predominant compound. Indoor PAH levels tended to be higher in Gothenburg and outdoor levels higher in Mexico City. The sum of PCBs ranged 59–2100 ng m −3, and seemed to be highest indoors in Gothenburg and Lancaster. PBDE levels (sum of seven) ranged 0.68–620 ng m −3, with the highest levels found in some indoor locations. OCPs (i.e. DDTs, HCHs, and chlordanes) were widely dispersed both outdoors and indoors at all three studied areas. In Gothenburg all POPs tended to be higher indoors than outdoors, while indoor and outdoor levels in Mexico City were similar. This could be due to the influence of indoor and outdoor sources, air exchange rates, and lifestyle factors. The study demonstrates how passive samplers can provide quick and cheap reconnaissance data simultaneously at many locations which can shed light on sources and other factors influencing POP levels in air, especially for the gaseous fractions.

Are the residents of former Yugoslavia still exposed to elevated PCB levels due to the Balkan wars? Part 2: Passive air sampling network

Many Eastern European countries suffer the lack of data on concentrations of persistent organic pollutants in the environmental matrices. This absence of information is preventing the local authorities from taking the adequate actions to protect the people and environment. This is even more alarming in the countries recently affected by the wars where the chemicals released to the environment during the military operations can cause a significant ecological damage and health effects on the population. A potential of passive air sampling technique as a tool capable of providing seasonally and spatially resolved information about the local sources and levels of contamination was explored in this study as a first step to the establishment of a cost-effective long-term monitoring in this area. The passive air samplers proved to be a powerful technique capable of detecting the concentrations ranging over four orders of magnitude providing the information very comparable with the conventional techniques.

Development and Calibration of a Resin-Based Passive Sampling System for Monitoring Persistent Organic Pollutants in the Atmosphere

Responding to a growing need for inexpensive and simple monitoring of persistent organic pollutants (POPs) in the atmosphere, a passive air sampling technique based on the sorption of gaseous pollutants to the sampling resin XAD-2, a styrene−divinylbenzene copolymer, has been developed. A quantitative understanding of the uptake kinetics of the passive air samplers (PAS) was obtained through a combination of field calibration studies, controlled wind tunnel experiments, and flow field simulations. Forty-two PAS were deployed for varying time periods up to 1 yr at three calibration stations in the Laurentian Great Lakes region and the Canadian High Arctic with ongoing conventional air sampling of organochlorine pesticides. The PAS take up quantifiable levels of POPs within a few weeks of deployment, and the amount of chemical collected increases steadily over a 1-yr sampling period. The uptake of POPs by the PAS is controlled by molecular diffusion and independent of wind velocity. The time-averaged air concentrations of organochlorine pesticides derived from the PAS data are comparable with those from HiVol sampling. This study suggests that the XAD-2 resin-based PAS can be used to derive at least semiquantitative information on the vapor-phase concentrations of POPs in the atmosphere and are suitable for the measurements of long-term average concentrations at the levels occurring in remote regions.

Detection of E. coli DH5alpha specific bacteriophage in the vicinity of a water treatment plant

Air in the vicinity of a water treatment plantscheduled for redevelopment was monitored foraerosols containing a bacteriophagespecific for the Escherichia coli (E.coli) strain DH5alpha bacterium. An assay forthe detection of the specific airbornebacteriophage was developed. Sampling wascarried out prior to and after completion ofdevelopment work to the plant. Preliminaryexperiments showed water from the plantcontains the bacteriophage specific for theE. coli DH5alpha bacterium. Two fieldstudies were completed before work on thetreatment plant began. The first study,conducted under wet and windy conditions, usedonly passive air sampling to monitor air at 3selected locations adjacent to the plant.E. coli DH5alpha specific bacteriophage waspositively detected, albeit at low levels. However, both the passive and a new direct airsampling technique were employed in the secondfield study, conducted under dry and windyconditions. In this instance, neither methoddetected specific bacteriophage. Further workwas undertaken 6 months after modifications tothe plant had been completed. Passive anddirect air sampling techniques were againemployed at each of the same 3 selectedlocations. Samples from both of these methodscontained no bacteriophage. As a check, thesamples were also analysed using an alternativeprocedure. No bacteriophage was detected. Theresults generated indicate that the levels ofairborne specific bacteriophage in the vicinityof the plant appear to be extremely low, andthe direct air sampling technique successful.

Atmospheric sampling of persistent organic pollutants: needs, applications and advances in passive air sampling techniques.

There are numerous potential applications for validated passive sampling techniques to measure persistent organic pollutants (POPs) in the atmosphere, but such techniques are still in their infancy. Potential uses include: monitoring to check for regulatory compliance and identification of potential sources; cheap/efficient reconnaissance surveying of the spatial distribution of POPs; and deployment in studies to investigate environmental processes affecting POP cycling. This article reviews and discusses the principles and needs of passive sampling methodologies. The timescales required for analytical purposes and for the scientific objectives of the study are critical in the choice and design of a passive sampler. Some techniques may operate over the timescales of hours/days, others over weeks/months/years. We distinguish between approaches based on "kinetic uptake" and "equilibrium partitioning". We highlight potentially useful techniques and discuss their potential advantages, disadvantages, and research requirements, drawing attention to the urgent need for detailed studies of sampler performance and calibration.