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Air pollution has become a major environmental risk as far as public health is concerned.It has been proposed that reduction in levels of air pollution may result in lessening of the global burden of disease. Monitoring and management of air pollution is being carried out since long.However, the causes of air pollution and effects of air pollution humans, animals and plants are yet to be fully unraveled. Moreover, management of air pollution is facing challenges due to lack of availability of suitable tools and techniques. The latter half of the 19th century was dominated with research on the recognition and description of different pollutants and to some extent towards the search for tools and techniques to control and reduce air pollution. One of the major air pollutants is atmospheric particulate matter. Re-suspended roadside dust is one of the sources ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT 2 of these particulate matters. Re-suspended dust is composed of several elements from different sources. The elemental composition of these dust particulates varies with their size and the size sometimes is dependent on the sources. The atmospheric dust particles find their way on to the surfaces of leaves on the roadside either under gravity or via impaction due to wind. Assessment of the elemental distribution in dust adsorbed over leaves as well as in the leaf tissues makes plants as suitable bio-monitor of air pollution. Moreover physiological alterations in plants also can indicate the level of pollution in the respective areas. Hence plants can be used as biomonitors and bio-indicators of air-pollution. Dust interception capacities of plants can be exploited to use them as sinks for atmospheric particulate pollutants. Literatures available on these aspects are reviewed and the highlights are depicted in this review paper. This review report has five groups i.e. reports on worsening air quality around the world, studies on dust interception capacity of plants, physiological alterations in plants in response to dust load, elemental distribution in different environmental samples (ambient air, dust from plant canopies, roadside dust and plant tissues) and elemental and mineralogical profiling of urban dust particulates with respect to size distribution.

Polycyclic aromatic hydrocarbons (PAHs) are compounds with two or more fused benzene rings produced by incomplete combustion of organic substances involved in natural and anthropogenic processes. Children are exposed to these compounds through inhalation, dietary ingestion, and, also, soil at the playground. It has been well established that PAHs have carcinogenic, mutagenic, and teratogenic effects. Considering possible health risks due to PAHs exposure among children, the present study was carried out in collaboration with the Pediatrics Department, King George's Medical University (KGMU), Lucknow, to determine its exposure in children by estimating blood PAHs levels. Due to the variable composition of PAHs mixtures emitted from different environmental sources, any single compound or metabolite may not be representative of all exposure conditions. For these reasons, the measurement of blood PAHs levels as a possible biomarker, especially of the EPA (Environmental Protection Agency, USA) priority list, has been proposed. Acenaphthylene, anthracene, phenanthrene, fluoranthene, naphthalene, pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene were determined by HPLC-FD/UV. On the basis of the individual compound, the median (50th percentile) of naphthalene (19 ppb) was highest, however, benzo(a)pyrene (4.0 ppb) level was found to be lowest among all detected PAHs. The median level of total noncarcinogenic PAHs (113.55 ppb) was higher than the total carcinogenic PAHs (32.35 ppb) in blood samples of children. A significant correlation was found between period of time spent in the surrounding breathing zone of the cooking place and total noncarcinogenic PAHs (p < 0.05), while the blood carcinogenic PAHs level in children was found to be associated with lower status of their families (p < 0.05). It is speculated that there may be chances of health hazards through exposure to PAHs, those not yet declared hazardous and present at higher concentrations in the Indian environment. Further study with a larger sample size and accompanying environmental data is desired to validate the findings of this pilot study and strengthen the database of PAHs exposure in India.

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This study aimed to investigate aerosol chemical characteristics and to obtain the chemical profile of near-source biomass burning (BB) aerosols at a site (675 m a.s.l.) in Sonla, Northern Vietnam. Particulate matter (PM) with an aerodynamic diameter less than or equal to 2.5 µm (PM 2.5 ) was collected over a 24 h sampling period as part of the Seven South East Asian Studies (7-SEAS) campaign. The studies were conducted when BB was highly active -that is, in the spring of 2012 and 2013. The collected particles were analyzed for carbonaceous fractions and water-soluble components, in addition to the mass concentration. Data obtained were further analyzed to determine the stable species profile by classifying the 5-day air-mass backward trajectories. The average PM 2.5 mass concentrations were 51 ± 19 µg m -3 and 57 ± 27 µg m -3 in 2012 and 2013, respectively. Carbonaceous contents dominated BB aerosol, with 59% ± 9% and 58% ± 9% in organic carbon (OC) and 9% ± 3% and 10% ± 3% in elemental carbon (EC) of PM 2.5 in 2012 and 2013, respectively. Of the 8 carbonaceous fractions analyzed thermo-optically for PM 2.5 , OC3 (evolution temperature at 280°C-480°C) was most abundant in OC fractions, and EC1-OP (elemental carbon evolved at 580°C minus the pyrolized OC fractions) was predominant in EC fractions in most occasions. Among the measured water-soluble inorganic ions, NH 4 + and SO 4 2-widely varied, indicating the influence of different trajectory origins. This finding was confirmed by trajectory classification of aerosol data. The trajectories were also distinguished with respect to char-EC to soot-EC ratio, and water-soluble OC. These characteristics were highest in the trajectory from the BB source area.

This study presents measurements of aerosol chemical properties at Sonla, northern Vietnam (675 m a.s.l.) during spring time, when biomass burning (BB) was very active in the northern Indochina Peninsula, as part of the 7-SEAS (Seven South East Asian Studies) campaign in 2013. The gas chromatography-mass spectrometry (GC-MS) analysis of BB markers in 14 selected samples indicated that mixed softwood, hardwood, grass, and non-woody vegetation were burned. More than 50 organic compounds including levoglucosan, lignin and resin products, sugar and sugar alcohol compounds, fatty acids, phthalate esters, aromatic acids, poly-acids, and biogenic oxidation products (e.g., 2-methyltetrols, alkene triols, 3-hydroxyglutaric acid) were measured in PM 2.5 . Levoglucosan, a BB tracer, was the predominant species among aerosol sugars, with an average concentration of 1.62 ± 0.89 µg m -3 , comprising 2.23 ± 0.5% of PM 2.5 mass. For the collection period of the selected samples, backward air mass trajectories were classified into the source regions of Indochina (BBIC), southern China (BBSC), and the South China Sea (BBSS). All resolved molecular compounds show their dominance on the trajectory from BBIC, verifying the BB smoke origin of that region. Trajectory classification provides additional information, such as higher level of diethyl phthalate associated with BBSC trajectory, revealing urban or industrial influence, and more low-molecular-weight than high-molecular-weight fatty acids, indicating distributions with more microbial and lesser plant wax/vegetation burning contributions along the BBSC trajectory. In addition, we report, for the first time, stable carbon isotopic data (δ 13 C) for PM 2.5 aerosols in northern Vietnam, which ranged from -26.6 to -25.4‰ in PM 2.5 , indicating contributions from burning of C 3 plants and fossil fuel combustion.

Mangroves have wide applications in traditional medicines due to their several therapeutic properties. Potentially toxic elements (PTEs), in mangrove habitats, need serious concern because of their toxicity, bioaccumulation capacity and ecotoxicological risks. In the current study, we aimed to examine sediment quality and bioaccumulation of PTEs in a mangrove-dominated habitat of Sundarban, India, and their relation with antimicrobial property of ten mangrove species of the region. Antimicrobial activity of different solvent fractions of mangrove leaves was assessed against seven microorganisms. The highest antimicrobial activity was detected in ethyl acetate and acetone-extracted fractions of Avicennia alba. Various sediment quality indices revealed progressively deteriorating nature of surface sediment having moderate contamination, however, low ecotoxicological risk. The accumulation factors (AF) for different PTEs indicate a gradual metal bioaccumulation in leaf tissue. Antimicrobial activities indicated both positive and negative correlations with manganese (Mn), copper (Cu), iron (Fe) and zinc (Zn) concentrations of mangrove species. Concentration of Mn showed a significant correlation with almost all the fractions, whereas Cu had correlation with ethyl acetate, acetone and methanol fractions (P < 0.05). The AF of Mn and Cu exhibited correlation with antimicrobial activities of acetone and methanol fractions, whereas Fe and Zn had correlation with hexane and ethyl acetate fractions. Overall, Mn, Fe, Cu and Zn concentrations of Acanthus ilicifolius and Avicennia alba leaves and in the surface sediments demonstrated the strongest association (P < 0.05) with their antimicrobial activity as also depicted in correlation and cluster analysis studies. Thus, this study will help to establish a link between the PTEs in mangrove ecosystem with their bioactivity.