Infant Exposure to Resuspended Particles from Carpeted Flooring: Experimental Chamber Study with a Simplified Mechanical Crawling Infant

Airborne particles of biological origin – bioaerosols – are present everywhere, including the indoor environment where people spend considerable amounts of time, and exposure to such materials via inhalation can have a number of health implications. Bioaerosol dynamics can occur through a variety of mechanisms, among them resuspension of deposited particles due to human activity. Because the breathing zone of infants is at a much lower height than that of adults, there is reason to suspect that infants are exposed to greater concentrations of bioaerosols resuspended from the floor, though knowledge in this specific area is limited. To investigate, a mechanical infant was used to simulate crawling over carpeting and particle concentrations for varying size groups were recorded using an optical particle sizer (OPS) at heights corresponding to both infant and adult breathing zones. In addition, resuspension tests on the infant breathing zone were repeated following vacuuming of the carpets to observe the effect of vacuuming on exposure rates. Results show that, as a result of infant crawling, concentrations of resuspended particles are significantly higher in the infant breathing zone compared to the bulk air, which is reduced but not quite eliminated by vacuuming. In addition, the mechanisms governing particle concentrations in the breathing zone appears to differ from those of the bulk environment. This study demonstrates that infant crawling causes significant resuspension of particles in the infant breathing zone, making it a prominent contributor to infant bioaerosol exposure worthy of further investigation

Purdue Air Sense: A Methodology for Improving the Accuracy of Ambient Aerosol Mass Concentration and Size Distribution Measurement with Low-Cost Optical Sensing Techniques

There is a global lack of a means for monitoring air pollutant levels at a local level due to expensive and bulky instrument requirements. It is important to monitor toxic gas levels, as well as particulate matter levels, in the atmosphere to study their effects on human health and to further develop city- and community-level air pollution solutions. In this study, with the means of a Raspberry Pi, low-cost Alphasense Optical Particle Counter and gas sensors, and methodical calibration techniques, we built a portable 3-D printed module powered by clean electricity generated by an on-board Voltaic solar cell that measures concentrations of ozone, NOx, CO and CO2 as well as coarse and fine particulate matter (PM) in ambient air. To calibrate these sensors, we used laboratory-grade reference instruments as the benchmark and set it up so that the calibrated data is displayed on the Purdue AirSense website in real time. We also accounted for temporal and humidity variations and generated PM size distribution plots under 0.3 microns in diameter, which the low-cost sensors are not able to detect, using regression techniques. This module can be used in many remote areas for air monitoring and implementing localized solutions to the air pollution problem. Moreover, due to portability, it can also be used on vehicles for vehicle pollution monitoring, and in classrooms, for educating the public about air quality monitoring

Air Cleaning Performance of a Biowall for Residential Applications

An active botanical air filtration system, called the Biowall, is used to improve indoor air quality (IAQ) and provide the potential for energy savings for air conditioning in residential buildings. The Biowall is an integral part of the HVAC system to actively filter the return air from Volatile Organic Compounds (VOCs).   The Biowall was recently evaluated in an environmental chamber with controlled conditions to measure its air cleaning characteristics.  A ‘pull-down’ test method, in which a known amount of contaminant was introduced to the chamber so that its decay could be monitored over time, was used for the evaluation.  The decay rate of the contaminants with the Biowall present was then compared to the decay rate of an empty chamber and the growth media alone (without plants). The experiments also evaluated the filter at different airflow rates across the filter and different moisture content inside the growth media. Based on the experimental data, the clean air delivery rates (CADR) of the Biowall were quantified. The preliminary results showed that the Biowall removed up to 90% of the introduced contaminants within two to three hours inside a sealed environmental chamber. This could potentially translate into energy savings on the ventilation systems up to 25%. In addition to savings on ventilation, the Biowall could contribute in saving heating and cooling energy by reducing the air temperature during summer months, and reducing the air dryness during the winter months.  Beyond these quantifiable benefits, a Biowall provides an intangible benefit by adding a pleasant natural aesthetic to a home

Purdue AirSense: An Affordable Way to Measure and Study Air Pollution

Air pollution is a major health hazard worldwide, accounting for one-eighth of all deaths in 2012 (World Health Organization). Globally, there is a severe lack of ground-based spatiotemporal monitoring of gaseous and particulate air pollutants, particularly in Africa, South and Central America, and the Middle East. This is in great part due to the high costs of air quality instrumentation that meet accuracy and reliability criteria set by monitoring agencies. The air quality data that is available is often not presented to the public in a user-friendly manner. Taking advantage of recent developments in low-cost sensing technologies, an integrated sensor network based on the Raspberry Pi platform was modeled for \u3c1.5K/unit. Each module includes sensors for coarse and fine particulate matter (PM10, PM2.5, PM1), ozone, nitrogen oxides, and carbon monoxide. The sensors can stream data to a user-friendly website where students and the general public can analyze large air quality data sets. Calibration protocols are being developed to ensure reliability of sensors’ outputs. The observed benefits of an integrated set of low-cost sensors, compared to traditional air quality monitoring sites, are increased spatial coverage and a factor of 100 difference in cost. These innovations will make people’s lives better as we work towards reducing the adverse effects of air pollution through increased awareness and availability of open-source data among the central Indiana community

Purdue AirSense: An Open-source Air Quality Monitoring System

Ambient air pollutants have received increasing attention in recent years since studies have demonstrated their adverse health effects. To address the sparsity of concentration data for major ambient air pollutants, researchers have introduced several new low-cost measurement methods. Despite these efforts, only a few gas concentration data and aerosol size distribution data are publicly accessible through online platforms. In this study, we used Alphasense sensors to build an innovative low-cost portable sensor system that measures the concentration of ozone, CO, NOx, and coarse and fine particulate matter (PM). Alongside the portable sensor system, we assembled lab-grade analytical instruments in a central monitoring station to measure the background concentrations of ozone, CO, NOx, and PM (coarse, fine, and ultrafine) in the West Lafayette region and to validate the sensor system measurements. Data from the low-cost sensor module were retrieved and published on a web platform that was built to present major ambient pollutant data in a user-friendly manner for classroom use. Particularly, the Alphasense OPC-N2 sensor captured temporal variations of coarse- and fine-particle concentrations. Thus, the low-cost module, if massively distributed, could be used to assess local exposures; the central monitoring station could capture regional concentration trends in the longer term. Furthermore, the web platform could educate the public on air quality monitoring and promote citizen science

Mobile Aerosol Measurement in the Eastern Mediterranean – A Utilization of Portable Instruments

Air pollution research and reports have been limited in the Middle East, especially in Jordan with respect to aerosol particle number concentrations. In this study, we utilized a simple "mobile setup" to measure, for the first time, the spatial variation of aerosol concentrations in Eastern Mediterranean. The mobile setup consisted of portable aerosol instruments to measure particle number concentrations (cut off sizes 0.01, 0.02, 0.3, 0.5, 1, 2.5, 5, and 10 mu m), particle mass concentrations (PM1, PM2.5, and PM10), and black carbon concentration all situated on the back seat of a sedan car. The car was driven with open windows to ensure sufficient cabin air ventilation for reliable outdoor aerosol sampling. Although the measurement campaign was two days long, but it provided preliminary information about aerosols concentrations over a large spatial scale that covered more than three quarters of Jordan. We should keep in mind that the presented concentrations reflect on road conditions. The submicron particle concentrations were the highest in the urban locations (e.g., Amman and Zarqa) and inside cities with heavy duty vehicles activities (e.g., Azraq). The highest micron particle concentrations were observed in the southern part of the country and in places close to the desert area (e.g., Wadi Rum and Wadi Araba). The average submicron concentration was 4.9 x 10(3)-120 x 10(3) cm-3 (5.7-86.7 mu g m(-3)) whereas the average micron particle concentration was 1-11 cm(-3) (8-150 mu g m(-3), assume rho(p) = 1 g cm(-3)). The main road passing through Jafr in the eastern part of Jordan exhibited submicron concentration as low as 800 cm(-3). The PM10 concentration consisted of about 40-75% as PM1. The black carbon (BC) concentration variation was in good agreement with the PM1 as well as the submicron particle number concentration.Peer reviewe

Black Carbon and Particulate Matter Concentrations in Eastern Mediterranean Urban Conditions: An Assessment Based on Integrated Stationary and Mobile Observations

There is a paucity of comprehensive air quality data from urban areas in the Middle East. In this study, portable instrumentation was used to measure size-fractioned aerosol number, mass, and black carbon concentrations in Amman and Zarqa, Jordan. Submicron particle number concentrations at stationary urban background sites in Amman and Zarqa exhibited a characteristic diurnal pattern, with the highest concentrations during traffic rush hours (2–5 × 104 cm−3 in Amman and 2–7 × 104 cm−3 in Zarqa). Super-micron particle number concentrations varied considerably in Amman (1–10 cm−3). Mobile measurements identified spatial variations and local hotspots in aerosol levels within both cities. Walking paths around the University of Jordan campus showed increasing concentrations with proximity to main roads with mean values of 8 × 104 cm−3, 87 µg/m3, 62 µg/m3, and 7.7 µg/m3 for submicron, PM10, PM2.5, and black carbon (BC), respectively. Walking paths in the Amman city center showed moderately high concentrations (mean 105 cm−3, 120 µg/m3, 85 µg/m3, and 8.1 µg/m3 for submicron aerosols, PM10, PM2.5, and black carbon, respectively). Similar levels were found along walking paths in the Zarqa city center. On-road measurements showed high submicron concentrations (>105 cm−3). The lowest submicron concentration