Inner-filter effect of nitrogen-doped carbon quantum dots-MnO2 nanotubes for smartphone-integrated dual-mode sensing of glutathione and captopril.

Nitrogen-doped carbon quantum dots (N-CQDs) exhibit unique fluorescence properties and are considered one of the best candidates for the development of fluorescence-based sensors for the detection of many analytes. In this work, a smartphone-assisted fluorescent sensor has been developed using N-CQDs and MnO2 nanotubes (MnO2 NTs) for the detection of glutathione (GSH) and captopril (CAP). N-CQDs were facilely synthesized via the solvothermal method, where o-phenylenediamine (o-PD) and urea were used as nitrogen precursors. Likewise, MnO2 NTs were synthesized using the hydrothermal method. Relying on the excellent fluorescence quenching ability of MnO2 NTs, a nanocomposite of N-CQDs and MnO2 NTs is prepared, wherein the fluorescence intensity of N-CQDs was effectively quenched in the presence of MnO2 NTs via the inner-filter effect (IFE). The addition of thiolated compounds (GSH and CAP) helped in the recovery of the fluorescence of N-CQDs by triggering the redox reaction and decomposing the MnO2 NTs. An investigation of fluorescence along with smartphone-based studies by evaluating the gray measurement using Image J software showed a great response towards GSH and CAP providing LODs of 4.70 µM and 5.22 µM (fluorometrically) and 5.76 µM and 2.81 µM (smartphone-based), respectively. The practical applicability of the sensing system has been verified using human blood plasma samples.

Chemical fractionation of particulate-bound metal(loid)s to evaluate their bioavailability, sources and associated cancer risk in India.

Eleven potentially toxic metal(loid)s (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), proven source markers of mineral based coal-fired industrial emissions and vehicular exhausts, were analysed using the four steps sequential extraction method to evaluate metal(loid)s concentration, in total and fractions of bioavailable and non-bioavailable for fine (PM2.5) and coarse (PM10-2.5) particulate modes. A total of 26-day-wise samples with three replications (total number of samples = 78) were collected in January-December 2019 for each PM10 and PM2.5 at an urban-residential site in India. In both the coarse and fine particulate modes, Pb and Cr have respectively shown the highest and lowest total concentrations of the measured metal(loid)s, indicating the presence of coal-fired power plants and heavy vehicular activities near to study area. In addition, Mn has shown highest bioavailable fraction for both coarse and fine particulate modes. More than 50 % of metal(loid)s concentration, in total to a bioavailable fraction (BAF) were observed in case of As, Cd, Cr, Co, Mn, Ni, and Pb of PM2.5. Mn and Zn have shown similar behaviour in the case of coarse particulate mode. Source apportionment of metal(loid)s bioavailable fractions using positive matrix factorization (PMF 5.0) has found three significant sources: crustal and natural dust (30.04 and 39 %), road traffic (49.57 and 20 %), and industrial emission (20.39 and 41 %) for coarse and fine particulate mode, respectively. Cancer risk through the inhalation pathway was high in total concentration but lower in BAF concentration in both age groups (children and adults).

Smartphone-integrated printed-paper sensor designed for on-site determination of dimethoate pesticide in food samples.

Herein, a user-friendly and portable smartphone-integrated printed-paper sensor was designed with Cu@Ag nanoparticles (NPs) for on-site monitoring of dimethoate pesticide in food samples, and the results obtained are compared with those obtained by UV-vis spectrophotometry. The working principle for identification of dimethoate pesticide is the change of yellow color NPs to reddish-yellow with associated bathochromic shift of absorption peak when pesticide introduced onto the fabricated paper or glass vial containing the NPs. A smartphone-color detector App and colorimetry were used for quantitative analysis of dimethoate in food samples. Linearity range for analysis of dimethoate using paper sensor and colorimetry were 100-2000 µgL-1 and 50-2500 µgL-1 with detection limit of 30 and 16 µgL-1, respectively. The advantages of using smartphone-integrated paper devices are rapid, instrument-free detection and economic in terms of consumption of lower amounts of NPs solution compared to other NPs-based colorimetric methods.

Using functionalized asphaltenes as effective adsorbents for the removal of chromium and lead metal ions from aqueous solution.

For the first time, functionalized asphaltene has been designed, synthesized, and used for the removal of heavy metals from the water. Asphaltene was separated from the crude oil with the addition of n-alkanes. Asphaltene having a complex chemical structure including multilayered and clustered aromatic fused rings bearing aliphatic chains. Asphaltene also contains heteroatoms like N, S, and O atoms along with Ni and V as prominent trace metals. On functionalization of asphaltene with nitric acid, the aliphatic chains and some of the naphthenic rings broke down and developed -COOH, -CO, C-O, and other oxygen functional groups which are playing key roles as surface-active agents in the removal of the heavy metals via chemisorption. The study was conducted using different parameters such as dose, time, pH, and concentration. The adsorption efficiency for this material at pH 4 is excellent for the removal of chromium and lead. The Langmuir, Freundlich and Temkin adsorption isotherm models as well as Lagergren pseudo second-order kinetic model were investigated. The positive enthalpies ΔHs confirm that the adsorption process is endothermic and the negative free energies ΔGs confirm the spontaneity of the process. The good efficiency of the adsorption implies the efficacy in the removal of the heavy metal ions, as well as the good efficiency in desorption, which implies the excellent recovery of the adsorbent. The effective reusability of this adsorbent makes it applicable for industrial water treatment from contaminants.

Inkjet-printed paper-based colorimetric sensor coupled with smartphone for determination of mercury (Hg2+).

We report an inkjet-printed paper based colorimetric sensor with silver nanoparticles (AgNPs) using smartphone and color detector App for on-site determination of mercuric ion (Hg2+) from environmental water samples. The AgNPs printed on Whatman filter paper (No. 1) is employed for detection of Hg2+ which is reliant on the color change of NPs from yellow to discoloration depending on the concentration of target analyte in sample solution. The quantitative determination was performed by calculating the signal intensity of AgNPs on printed paper substrate after the introduction of Hg2+ using smartphone and RGB color detector. The mechanism for detection of Hg2+ on paper substrate is verified using UV-Vis spectrophotometry (UV-Vis), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS) and basic chemical assays. The linear range acquired for paper based colorimetric detection in the range of 40-1200 µgL-1 with limit of detection of 10 µgL-1. The results obtained using an inkjet-printed paper-based chemical sensor combined with a smartphone is validated with data of inductively coupled plasma-atomic emission spectroscopy (ICP-AES) measurement. The advantages of paper based detection are simple, rapid, economic and can be applied at the sample sources for determination of Hg2+.

Biogenic secondary organic aerosol formation in an urban area of eastern central India: Seasonal variation, size distribution and source characterization.

Samples of ambient aerosols were collected at an urban site of eastern central India from monsoon to summer 2016-17 for the characterization of biogenic secondary organic aerosols (BSOA). The BSOA tracers derived from isoprene, α/ß-pinene and ß-caryophyllene in size-distributed aerosols were studied. Concentrations of total SOAI (Isoprene secondary organic aerosols) were found more abundant than α/ß-pinene in summer, while contradictory trends were found in the winter season, where SOAM (monoterpene derived SOA) and SOAS (sesquiterpenes derived SOA) were dominated. Size-distribution study revealed that most of the BSOA were formed in the aerosol phase and dominated in fine mode, except cis-pinonic acid. They were formed in the gaseous phase and partitioned onto the aerosol phase. The alkaline nature of mineral dust particles that triggered the adsorption of gaseous species onto pre-existing particles could be the reason for bimodal size distribution with major coarse mode peak and miner fine mode peak. Temporal variations suggest that the BSOA must be derived from terrestrial vegetation and biomass burning. The isoprene SOC (secondary organic carbon) contributed 0.91%, 1.38%, 0.88% and 1.04% to OC during winter, summer, post-monsoon and monsoon season, respectively. The isoprene SOC in fine mode was found to be higher than the coarse mode.

Ambient PM2.5 exposure and rapid spread of COVID-19 in the United States.

It has been posited that populations being exposed to long-term air pollution are more susceptible to COVID-19. Evidence is emerging that long-term exposure to ambient PM2.5 (particulate matter with aerodynamic diameter 2.5 µm or less) associates with higher COVID-19 mortality rates, but whether it also associates with the speed at which the disease is capable of spreading in a population is unknown. Here, we establish the association between long-term exposure to ambient PM2.5 in the United States (US) and COVID-19 basic reproduction ratio R0- a dimensionless epidemic measure of the rapidity of disease spread through a population. We inferred state-level R0 values using a state-of-the-art susceptible, exposed, infected, and recovered (SEIR) model initialized with COVID-19 epidemiological data corresponding to the period March 2-April 30. This period was characterized by a rapid surge in COVID-19 cases across the US states, implementation of strict social distancing measures, and a significant drop in outdoor air pollution. We find that an increase of 1 µg/m3 in PM2.5 levels below current national ambient air quality standards associates with an increase of 0.25 in R0 (95% CI: 0.048-0.447). A 10% increase in secondary inorganic composition, sulfate-nitrate-ammonium, in PM2.5 associates with ≈10% increase in R0 by 0.22 (95% CI: 0.083-0.352), and presence of black carbon (soot) in the ambient environment moderates this relationship. We considered several potential confounding factors in our analysis, including gaseous air pollutants and socio-economical and meteorological conditions. Our results underscore two policy implications - first, regulatory standards need to be better guided by exploring the concentration-response relationships near the lower end of the PM2.5 air quality distribution; and second, pollution regulations need to be continually enforced for combustion emissions that largely determine secondary inorganic aerosol formation.

Biogenic secondary organic aerosols: A review on formation mechanism, analytical challenges and environmental impacts.

The review initiates with current state of information on the atmospheric reaction mechanism of biogenic volatile organic compounds (BVOCs) and its fate in the atmosphere. The plants release BVOCs, i.e., isoprene, monoterpenes, and sesquiterpenes, which form secondary organic aerosols (SOA) upon oxidation. These oxidation reactions are primarily influenced by solar radiations along with other meteorological parameters viz.; temperature and relative humidity, therefore, the chemistry behind SOA formation is different during day than the night time. The review throws light upon the day and nighttime formation mechanism of SOA, recent advancements in the analytical techniques available for the measurements, and its impact on the environment. Studies have revealed that day time SOA formation is dominated by OH and O3, however, NOx initiated SOA production is dominated during night. The formation mechanism addresses that the gaseous products of VOCs are firstly formed and then partitioned over the pre-existing particles. New particle formation and biomass-derived aerosols are found to be responsible for enhanced SOA formation. 2-Dimensional gas chromatography-mass spectrometer (2D-GC/MS) is observed to be best for the analysis of organic aerosols. Radiative forcing (RF) SOA is observed to be a useful parameter to evaluate the environmental impacts of SOA and reviewed studies have shown mean RF in the ranges of -0.27 to +0.20 W m-2.

Influence of fireworks emission on aerosol aging process at lower troposphere and associated health risks in an urban region of eastern central India.

To study the influence of fireworks in atmospheric aerosols and their effect on health during the extreme firework days, fireworks tracer metals and carbonaceous species in size-distributed aerosols in the lower troposphere at Raipur in eastern central India were investigated during the 2018 Deepawali festival. Aerosol samples were collected, before Deepawali period (BDP, n = 5), during Deepawali period (DDP, n = 5) and after Deepawali period (ADP, n = 5). Bimodal size-distribution with intense fine mode peak was found for Na during DDP. Bimodal distribution with fine mode intense peak was found for K during DDP. The bimodal size distribution of K was found common for other events because of biomass burning emissions, whereas high intense peak during DDP indicated mixed sources from biomass burning and fireworks. During DDP, K and Ca were well correlated (r2 = 0.93) together. Strong metal-metal correlations were found between the following pairs, Zn-Fe, Cu-Fe and Cu-Ca, which indicated the similar firecrackers burning source. The atmospheric aging of aerosols was also found significantly high during fireworks days. Aging of aerosols were higher because of heterogeneous reactions of SO2 and NOx on aerosols directly emitted from fireworks. The observed high values of inhalation dose of elemental carbon during DDP period imposed higher risk of respiratory diseases. This study has provided carbonaceous fractions composition data as a tool to detect the aging processes of fireworks in ultra-fine, fine and coarse mode particles during the extreme firework days. Inhalation doses were calculated to establish potential influence on human health.

L-cysteine modified silver nanoparticles for selective and sensitive colorimetric detection of vitamin B1 in food and water samples.

The use of L-cysteine modified silver nanoparticles (Cys-capped AgNPs) as a colorimetric probe for determination of vitamin B1 (thiamine) is described in the present work. This method is based on the measurement of red shift of localized surface plasmon resonance (LSPR) band of Cys-capped AgNPs in the region of 200-800 nm. The color of Cys-capped AgNPs was changed from yellow to colorless by the addition of vitamin B1. The mechanism for detection of vitamin B1 is based on the electrostatic interaction between positively charged vitamin B1, which causes the red shift of LSPR band from 390 nm to 580 nm. The interaction between Cys-capped AgNPs and vitamin B1 was theoretically explored by density function theory (DFT) using LANL2DZ basis sets with help of Gaussian 09 (C.01) program. The morphology, size distribution and optical properties of Cys-capped AgNPs were characterized by transmission electron microscope (TEM), UV-Visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS) techniques. The method is linear in the range of 25-500 µg mL-1 with correlation coefficient (R2) 0.992 and limit of detection of 7.0 µg mL-1. The advantages of using Cys-capped AgNPs as a chemical sensor in colorimetry assay are being simple, low cost and selective for detection of vitamin B1 from food (peas, grapes and tomato) and environmental (river, sewage and pond) water samples.

Smartphone coupled with paper-based chemical sensor for on-site determination of iron(III) in environmental and biological samples.

We report a smartphone-paper-based sensor impregnated with cetyltrimethylammonium bromide modified silver nanoparticles (AgNPs/CTAB) for determination of Fe3+ in water and blood plasma samples. The methodology for determination of Fe3+ is based on the change in signal intensity of AgNPs/CTAB fabricated on a paper substrate after the deposition of analyte, using a smartphone followed by processing with ImageJ software. The mechanism of sensing for detection and determination of Fe3+ is based on the discoloration of AgNPs which impregnated the paper substrate. The discoloration is attributed to the electron transfer reaction taking place on the surface of NPs in the presence of CTAB. Fe3+ was determined when the paper was impregnated with 1 mM AgNPs for 5 min of reaction time and the substrate was kept under acidic conditions. The linear range for determination of total iron in terms of Fe3+ was 50-900 µg L-1 with a limit of determination (LOD) of 20 µg L-1 and coefficient of variation (CV) of 3.2%. The good relative recovery of 91.3-95.0% and interference studies showed the selectivity of the method for determination of total iron in water and blood plasma samples. Smartphone-paper-based sensors have advantages of simplicity, rapidity, user-friendliness, low cost, and miniaturization of the method for on-site determination of total iron compared to methods that require sophisticated analytical instruments. Graphical abstract Smartphone-paper-based sensor with cetyltrimethylammonium bromide modified silver nanoparticles for determination of Fe3+ in water and blood plasma samples.

A direct DRS-FTIR probe for rapid detection and quantification of fluoroquinolone antibiotics in poultry egg-yolk.

We report a novel diffuse reflectance-Fourier transforms infrared (DRS-FTIR) spectral monitoring of fluoroquinolone antibiotics such as ciprofloxacin (CIP) and norfloxacin (NOR) for their quantification in poultry egg-yolks. To the best of our knowledge, this is the first report to describe the rapid quantitative determination of fluoroquinolone antibiotics in poultry egg samples using DRS-FTIR. The characteristic absorption peaks obtained at 1627 and 1026 cm-1 were used for optimization and determination of CIP and NOR, respectively. The linearity range obtained for the determination of CIP and NOR in egg samples was 0.05-0.50 ng mL-1 with limit of detection and limit of quantification of 0.032 and 1.551 ng mL-1 and 0.028 and 0.194 ng mL-1, respectively. Good recoveries were obtained in the range of 83.1-102.3% from poultry eggs samples using DRS-FTIR method. The advantages of the DRS-FTIR method are its simplicity, sensitivity and suitability for high-throughput analysis towards the food samples.

Household solid fuel burning emission characterization and activity levels in India.

Emission factors (EFs) of PM2.5, carbon fractions, major ionic (K+, Ca2+, NH4+, SO42-, NO3- and Cl-) and elemental (Al, Cr, Cu and Fe) species from combustion of commonly used household solid fuel were determined in 10 different states in India during cooking practices. The study involved sampling during actual household cooking involving use of a variety of fuels including coal balls (CB), fuel wood (FW), dung cakes (DC), crop residues (CR), mixed fuels (MF: dung cakes + fuel woods). Species-wise highest EFs (g·kg-1) were: 34.16 ±â€¯10.1 for PM2.5 (CB), 14.18 ±â€¯5.8 for OC (CB), 2.33 ±â€¯1.4 for EC (DC), 1.03 ±â€¯0.2 for K+ (CR), 2.21 ±â€¯0.6 NH4+ (DC), 0.61 ±â€¯0.2 for NO3- (CB), 0.59 ±â€¯0.1 for SO42- (CB), 0.69 ±â€¯0.1 for Cl- (CR) among the fuels. Higher OC EFs for CB could be attributed to higher moisture content (>13%) in coal-powder that is used to handmade coal balls. It is observed that, in general, OC3 and EC1 were the dominant thermally evolved carbon mass fractions. The study averaged MCE values were in the range 0.93-0.98, which could be attributed to higher variability in flaming and smoldering episodes during the combustion of selected fuels. Sum of ionic EFs for emissions from DC, CR and MF were found to be higher than those observed for FW and CB. The K+/EC and Cl-/EC (~1) ratios could be better indicators of CR fuels to differentiate it from FW, whereas NH4+/EC (~1) is suitable to indicate DC. Average annual emission estimates of PM2.5 (2.00 ±â€¯0.53 Tg·yr-1), OC (0.86 ±â€¯0.23 Tg·yr-1) and EC (0.11 ±â€¯0.02 Tg·yr-1) for tested fuels are evaluated to be contributing 27, 15 and 4% of total PM2.5, OC and EC, respectively, toward annual emission budget from different anthropogenic activities in India.

Temporal and spatial variations of PM2.5 organic and elemental carbon in Central India.

This study describes spatiotemporal patterns from October 2015 to September 2016 for PM2.5 mass and carbon measurements in rural (Kosmarra), urban (Raipur), and industrial (Bhilai) environments, in Chhattisgarh, Central India. Twenty-four-hour samples were acquired once every other week at the rural and industrial sites. Twelve-hour daytime and nighttime samples were acquired either a once a week or once every other week at the urban site. Each site was equipped with two portable, battery-powered, miniVol air samplers with PM2.5 inlets. Annual average PM2.5 mass concentrations were 71.8 ± 27 µg m-3 at the rural site, 133 ± 51 µg m-3 at the urban site, and 244.5 ± 63.3 µg m-3 at the industrial site, ~ 2-6 times higher than the Indian Annual National Ambient Air Quality Standard of 40 µg m-3. Average monthly nighttime PM2.5 and carbon concentrations at the urban site were consistently higher than those of daytime from November 2015 to April 2016, when temperatures were low. Annual average total carbon (TC = OC + EC) at the urban (46.8 ± 23.8 µg m-3) and industrial (98.0 ± 17.2 µg m-3) sites also exceeded the Indian PM2.5 NAAQS. TC accounted for 30-40% of PM2.5 mass. Annual average OC ranged from 17.8 ± 6.1 µg m-3 at the rural site to 64 ± 9.4 µg m-3 at the industrial site, with EC ranging from 4.51 ± 2.2 to 34.01 ± 7.8 µg m-3. The average OC/EC ratio at the industrial site (1.88) was 18% lower than that at the urban site and 52% lower than that at the rural site. OC was attributed to 43.0% of secondary organic carbon (SOC) at the rural site, twice that estimated for the urban and industrial sites. Mortality burden estimates for PM2.5 EC are 4416 and 6196 excess deaths at the urban and industrial sites, respectively, during 2015-2016.

Coarse particle (PM10-2.5) source profiles for emissions from domestic cooking and industrial process in Central India.

To develop coarse particle (PM10-2.5, 2.5 to 10µm) chemical source profiles, real-world source sampling from four domestic cooking and seven industrial processing facilities were carried out in "Raipur-Bhilai" of Central India. Collected samples were analysed for 32 chemical species including 21 elements (Al, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, S, Sb, Se, V, and Zn) by atomic absorption spectrophotometry (AAS), 8 water-soluble ions (Na+, K+, Mg2+, Ca2+, Cl-, F-, NO3-, and SO42-) by ion chromatography, ammonium (NH4+) by spectrophotometry, and carbonaceous fractions (OC and EC) by thermal/optical transmittance. The carbonaceous fractions were most abundant fraction in household fuel and municipal solid waste combustion emissions while elemental species were more abundant in industrial emissions. Most of the elemental species were enriched in PM2.5 (<2.5µm) size fraction as compared to the PM10-2.5 fraction. Abundant Ca (13-28%) was found in steel-rolling mill (SRM) and cement production industry (CPI) emissions, with abundant Fe (14-32%) in ferro-manganese (FEMNI), steel production industry (SPI), and electric-arc welding emissions. High coefficients of divergence (COD) values (0.46 to 0.88) among the profiles indicate their differences. These region-specific source profiles are more relevant to source apportionment studies in India than profiles measured elsewhere.

PM2.5 pollution from household solid fuel burning practices in Central India: 2. Application of receptor models for source apportionment.

USEPA's UNMIX, positive matrix factorization (PMF) and effective variance-chemical mass balance (EV-CMB) receptor models were applied to chemically speciated profiles of 125 indoor PM2.5 measurements, sampled longitudinally during 2012-2013 in low-income group households of Central India which uses solid fuels for cooking practices. Three step source apportionment studies were carried out to generate more confident source characterization. Firstly, UNMIX6.0 extracted initial number of source factors, which were used to execute PMF5.0 to extract source-factor profiles in second step. Finally, factor analog locally derived source profiles were supplemented to EV-CMB8.2 with indoor receptor PM2.5 chemical profile to evaluate source contribution estimates (SCEs). The results of combined use of three receptor models clearly describe that UNMIX and PMF are useful tool to extract types of source categories within small receptor dataset and EV-CMB can pick those locally derived source profiles for source apportionment which are analog to PMF-extracted source categories. The source apportionment results have also shown three fold higher relative contribution of solid fuel burning emissions to indoor PM2.5 compared to those measurements reported for normal households with LPG stoves. The previously reported influential source marker species were found to be comparatively similar to those extracted from PMF fingerprint plots. The comparison between PMF and CMB SCEs results were also found to be qualitatively similar. The performance fit measures of all three receptor models were cross-verified and validated and support each other to gain confidence in source apportionment results.

PM2.5 pollution from household solid fuel burning practices in central India: 1. Impact on indoor air quality and associated health risks.

PM2.5 concentrations were measured in residential indoor environment in slums of central India during 2012-2013. In addition, a suite of chemical components including metals (Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb, Mo, Se, Sb, Na, Mg, K and Hg), ions (Na+, Mg2+, K+, Ca2+, F-, Cl-, NH4+, NO3- and SO42-) and carbon (OC and EC) were analyzed for all samples. Indoor PM2.5 concentrations were found to be several folds higher than the 24-h national ambient air quality standard (60 µg/m3) for PM2.5 in India, and the concentrations were found to vary from season to season. Mass closure was attempted for PM2.5 data, and close to 100 % mass was accounted for by organic matter, crustal material, secondary organic and inorganic aerosols and elemental carbon. Additionally, carcinogenic and non-carcinogenic health risks associated with exposure to indoor PM2.5 (inhalation, dermal and ingestion) were estimated and while exposures associated with dermal contact and ingestion were found to be within the acceptable limits, risk associated with inhalation exposure was found to be high for children and adults. Elements including Al, Cd, Co, Cr, Mn, Ni, As and Pb were present in high concentrations and contributed to carcinogenic and non-carcinogenic risks for residents' health. Results from this study highlight the need for efforts to reduce air pollution exposure in slum areas.

Spatio-temporal measurement of indoor particulate matter concentrations using a wireless network of low-cost sensors in households using solid fuels.

Many households use solid fuels for cooking and heating purposes. There is currently a knowledge gap in our understanding of the variations in indoor air quality throughout the household as most of the studies focus on the areas in the close proximity of the cookstove. A low-cost wireless particulate matter (PM) sensor network was developed and deployed in households in Raipur, India to establish the spatio-temporal variation of PM concentrations. The data from multiple sensors were acquired in real-time with a wireless system. Data collected from the sensors agreed well (R2 =0.713) with the reference data collected from a commercially available instrument. Low spatial variability was observed within the kitchen due to its small size and poor ventilation - a common feature of most rural Indian kitchens. Due to insufficient ventilation from open doors and windows, high PM concentrations similar to those found in the kitchen were also found in the adjoining rooms. The same household showed significantly different post-extinguished cookstove PM concentration decay rates (0.26mg/m3-min and 0.87mg/m3-min) on different days, owing to varying natural air exchange rates (7.68m3/min and 37.40m3/min).

Deleterious effects of incense smoke exposure on kidney function and architecture in male albino rats.

CONTEXT: Previous studies, including ours, have shown adverse effects of incense smoke on human health. However, the effect of incense smoke on kidney function and structure remains unknown. OBJECTIVE: To evaluate possible adverse effects of incense smoke on kidney function and architecture in albino rats after chronic exposure to Arabian incense. MATERIALS AND METHODS: Emission characteristics including particle size distribution, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) were determined by gravimetric and GCMS analyses. Kidney functional markers, oxidative stress and inflammatory markers were measured by standard or ELISA based procedures. Ultrastructural changes in kidney were examined by transmission electron microscope (TEM) and the gene expression of xenobiotic metabolizing enzymes including cytochrome P-450-1A1 (CYP1A1) and CYP1A2 were studied by real time PCR. RESULTS: Rats exposed to incense smoke demonstrated a significant increase in serum creatinine, uric acid, blood urea nitrogen (BUN), tissue malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α) and interleukin-4 (IL-4) levels and a significant decline in tissue reduced glutathione (GSH) and catalase activity. Incense smoke exposed rats also displayed marked ultrastructural changes in kidney tissue. Further, a significant increase in tissue gene expression of both CYP1A1 and CYP1A2 was noted in exposed rats. DISCUSSION: Changes to kidney functional markers and architecture appear to be mediated through augmented oxidative stress and inflammation. CONCLUSION: Long-term exposure to incense smoke may have deleterious effects on kidney function and architecture. Though, inhalation is the rout of exposure, findings of this study underscore that incense smoke may also have an effect on non-pulmonary tissues.

Emission of volatile organic compounds from religious and ritual activities in India.

Worshipping activity is a customary practice related with many religions and cultures in various Asian countries, including India. Smoke from incense burning in religious and ritual places produces a large number of health-damaging and carcinogenic air pollutants include volatile organic compounds (VOCs) such as formaldehyde, benzene, 1,3 butadiene, styrene, etc. This study evaluates real-world VOCs emission conditions in contrast to other studies that examined emissions from specific types of incense or biomass material. Sampling was conducted at four different religious places in Raipur City, District Raipur, Chhattisgarh, India: (1) Hindu temples, (2) Muslim graveyards (holy shrines), (3) Buddhist temples, and (4) marriage ceremony. Concentrations of selected VOCs, respirable particulate matter (aerodynamic diameter, <5 µm), carbon dioxide, and carbon monoxide were sampled from the smoke plumes. Benzene has shown highest emission factor (EF) among selected volatile organic compounds in all places. All the selected religious and ritual venues have shown different pattern of VOC EFs compared to laboratory-based controlled chamber studies.