Fluorescence based detection of bioaerosols to improve emissions characterization from environmental sources

Bioaerosols are ubiquitous in ambient air but there have been increasing concerns about their human exposure and to health impact due to ever increasing environmental emissions from sources such as biowaste and intensive agriculture facilities (Borlée et al. 2015). However, the knowledge on their risk of exposure to the public is limited mainly due to a lack of emission characterisation, in part due to the limitation of conventional methods for the detection and characterisation of ambient bioaerosols. Among emerging techniques, fluorescence spectroscopy has shown promise in detecting and broadly classifying bioaerosols (Pan et al. 2015). This paper provides the preliminary results of a study that aims to demonstrate the potential of a fluorescence based bioaerosol sensor unit to detect and quantify these in real time with a view to developing and advancing bioaerosol exposure assessment methodologies to various environmental sources

Microbial dynamics during various activities in residential areas of Lahore, Pakistan

Bioaerosols are ubiquitous in the atmosphere with their levels affected by a variety of environmental factors as well as type of activities being carried out at any specific time. The present study investigated how indoor activities influence bioaerosol concentrations in five residential houses of Lahore. Agar coated petri plates were exposed face upwards for twenty minutes in kitchens and living rooms during activity and non-activity periods. The temperature and relative humidity levels were noted as well. The bioaerosol concentrations in kitchens during the activity time ranged between 1022 to 4481 cfu/m3 and in living rooms from 1179 to 3183 cfu/m3 . Lower values were observed during non-activity periods. A paired-t test revealed a significant difference in bacterial loads during activity and non-activity times in both micro-environments (p = 0.038 in kitchen and p = 0.021 in living room). The predominant species identified were Micrococcus spp., Staphylococcus spp., and Bacillus spp. which are a common constituent of the indoor environment and are known to be opportunistic pathogens as well

Measurement of NO2 indoor and outdoor concentrations in selected public schools of Lahore using passive sampler

Higher levels of NO2 are a danger to human health especially for children. A seven day study was carried to find out the ambient concentrations of NO2in 27 schools of Lahore with the help of passive samplers. In each school three sites were selected, viz: laboratory, corridor and outdoors. After 7 days exposure the tubes were subjected to spectrophotometric analysis. Results showed that the maximum values measured in laboratory, outdoor and corridors were 376µg/m3 , 222µg/m3 and 77µg/m3 . Minimum values for laboratory, outdoor and corridors were 10µg/m3 , 20µg/m3 and 8µg/m3 . Factors affecting these values were laboratory activities and proximity to main roads. These values were significantly higher than the standard values defined by EPA. Therefore children in schools were at risk of developing health complications

Assessment of airborne particulate matter (PM2.5) in university classrooms of varying occupancy

Air pollution is a major concern in Pakistan. Levels of particulate matter (PM2.5) in educational built environments, have not yet been studied comprehensively in Pakistan. This study was conducted to assess relationships between indoor and outdoor particulate matter in classrooms of the University of the Punjab, Lahore, using a DUSTTRAK Aerosol Monitor (TSI Model 8520). Sampling for PM2.5concentrations was carried out simultaneously outdoors and indoors in different classrooms on the campus. According to the level of occupancy three classrooms were selected i.e. Classroom I: low occupancy, Classroom II: medium occupancy and Classroom III: high occupancy. Simultaneous outdoor measurements were carried out at rooftop of each classroom. A tracer method was used to measure the air change per hour in each classroom. The 24 hour average concentrations of PM2.5 in Classrooms I, II and III were observed to be 282 .g/m³, 75 .g/m³ and 673 .g/m³ whereas 24 hour average outdoor levels were 324 .g/m³, 121 .g/m³ and 998.g/m³ respectively. Results showed a significant impact of ambient air and occupancy level on PM2.5 levels inside classrooms and all observed values exceeded the WHO limit

Exposure to NO2 in occupational built environments in urban centre in Lahore

Increased economic growth, urbanisation and substantial rise in automobile vehicles has contributed towards the elevated levels of air pollution in major cities in Pakistan. Aone week study was conducted by using passive samplers to assess NO2 concentration in occupational built environments at two most congested and populated sites of Lahore. Both sites were locatedon the busy roads of Lahore. At Site-I the highest concentration was in outdoors followed by corridor and indoor. While at Site II all the sampling location wereindoors and level were comparable to that of outdoor levelsat Site I. The results suggest the likely contribution of ambient sources in exposure to indoor NO2 in educational and other occupational built environments in urban centres

Ethno-environmental knowledge as a tool to combat indoor air pollution in low income countries: a case study from rural communities in Pakistan

It has recently been estimated that 4 million deaths each year are associated with air pollution originating from household solid fuel use. Interventions to reduce biomass fuel-related emissions can yield a diverse stream of benefits including improved public health, socio-economic development, reduced land degradation and climate change mitigation. This study investigates the use of indigenous knowledge to inform interventions to combat indoor air pollution at a rural site in the Punjab province of Pakistan. The results indicate that the majority of people using biomass fuel had knowledge of its ill health effects. A range of methods were utilised to reduce indoor smoke including cooking in open spaces, use of chimneys, better ventilation and use of dry fuel. Education and housing type showed a statistically significant relationship with awareness of methods to reduce indoor exposure to biomass smoke. These findings lend support to the notion that communities have indigenous knowledge and their own methods to reduce exposure to indoor smoke from biomass fuels; this knowledge can be used as tool to design and implement sustainable intervention strategies to reduce the risk of exposure to indoor air pollution. It is recommended that a community based intervention focusing on locally manufactured improved stoves and better designed cooking spaces would be a suitable intervention in this region

Estimation of particulate matter and gaseous concentrations using low-cost sensors from broiler houses

Particulate and gaseous emissions from intensive poultry facilities are major public and environmental health concern. The present study was aimed at exploratively monitoring particulate matter (PM) and gaseous concentrations in controlled-environment facilities using low-cost sensors in Lahore, Pakistan. The indoors and outdoors of 18 broiler houses, grouped into three categories based on the age of birds: group I (1–20 days), group II (21–30 days) and group III (31–40 days), were examined. Low-cost sensors Dylos 1700 and Aeroqual 500 series with different gas sensor heads were used to monitor PM and different gases such as nitrogen dioxide (NO2), hydrogen sulphide (H2S), carbon dioxide (CO2) and methane (CH4), respectively. Overall, the mean PM and gaseous concentrations increased with the age and activity of birds as compared with the non-activity time of birds. Statistically significant differences were observed in all measured parameters among the groups. The negative correlation between indoor and outdoor environments for PM and gas concentrations at some broiler houses demonstrates the contribution of additional sources to emissions in outdoor environments. The findings contribute to our knowledge of temporal characteristics of particulate and gaseous concentrations from poultry facilities particularly in Pakistan and generally to the capability of using low-cost sensors to evaluate emissions from such facilities

Sources of Airborne Endotoxins in Ambient Air and Exposure of Nearby Communities—A Review

Endotoxin is a bioaerosol component that is known to cause respiratory effects in exposed populations. To date, most research focused on occupational exposure, whilst much less is known about the impact of emissions from industrial operations on downwind endotoxin concentrations. A review of the literature was undertaken, identifying studies that reported endotoxin concentrations in both ambient environments and around sources with high endotoxin emissions. Ambient endotoxin concentrations in both rural and urban areas are generally below 10 endotoxin units (EU) m−3; however, around significant sources such as compost facilities, farms, and wastewater treatment plants, endotoxin concentrations regularly exceeded 100 EU m−3. However, this is affected by a range of factors including sampling approach, equipment, and duration. Reported downwind measurements of endotoxin demonstrate that endotoxin concentrations can remain above upwind concentrations. The evaluation of reported data is complicated due to a wide range of different parameters including sampling approaches, temperature, and site activity, demonstrating the need for a standardised methodology and improved guidance. Thorough characterisation of ambient endotoxin levels and modelling of endotoxin from pollution sources is needed to help inform future policy and support a robust health-based risk assessment process

Cloning and analysis of NBS-LRR super family of resistance (R) genes in wheat (Triticum aestivum L.)

Abstract: Resistance (R) genes containing nucleotide binding site (NBS) and leucine rich repeats (LRR) are the most prevalent types of resistance (R) genes in plants. The objective of this study was to isolate, identify and analyze resistance genes from disease (rust) and resistant wheat lines by PCR based strategy. Fifteen degenerate primers were designed from the conserved kinase-la and hydrophobic domains of known NBS-LRR type R-genes and from EST data bases. Four advanced resistant lines and one susceptible wheat line was selected from the trap nursery. Out of hundred primer combinations only seventy five primer combinations showed amplification. Twenty two primer combination showed differential banding pattern which were not present in highly susceptible Morocco, were cloned in TA based cloning vector and got them sequenced. Sizes of sequenced nucleotides were between 500bp to 1500bp. The cloned fragments showed their DNA sequence similarity to known resistance (R) genes of NBS-LRR family. These results indicate that identified genes are the valuable source to use as disease resistance genes or to screen wheat resistant germplasm against different types of rusts