Ambient PM2.5 (particulate matter less than 2.5 μm) samples, collected in a 8-week wintertime sampling program in two residential sites of Bhilai, India during the Indian Diwali festival in November 2012, were chemically characterized for 38 chemical species including eight speciated carbonaceous fractions (SCFs) of elemental (EC) and organic carbon (OC), twenty one metallic elements, and nine water soluble ionic species. Our objectives were to investigate: 1) relative abundances of SCFs contained in PM2.5during the Diwali festival period compared to normal days, and 2) enrichment pattern of potential inorganic markers of firework emission in ambient PM2.5during the festival days. Eight-fold increase inPM2.5mass concentrations were measured during the Diwali festival days compared to concentrations occurring in normal days. Bursting of firecrackers in the residential streets have shown significant contribution to the emission markers (K, Mg, Zn, S, EC and OC) along with crustal markers (Ca, Fe, Al) in ambient PM2.5aerosol samples. Concentrations of water soluble ionic species were found to be 10 times greater than those found in normal days. Further, the anion/cation ratios were found to reach a factor of 2; indicating the acidic character of emissions resulting from fireworks. The relative abundance of SCFs and higher ratios of OC to EC during the Diwali episode suggested the significant formation of secondary organic carbon (SOC) aerosols. We estimate that aerosols emitted from firework bursting contribute up to 32% of total ambient PM2.5 during the Diwali festival.

Several have been performed to evaluate the mutagenicity of soil samples in urban and industrial areas. The use of uncontaminated reference areas has been an obstacle to the study of environmental mutagenesis. The study aimed to indicate a methodology to define reference areas in studies of environmental contamination based on “Ambient Background Concentration” of metallic elements associated with the Salmonella/microsome assay. We looked at three potential reference areas, two of them close by the industrial sources of contamination (São Jerônimo reference, near the coal-fired power plant, and Triunfo reference, near the wood preservative plant), but not directly influenced by them and an area located inside a protected area (Itapuã reference). We also carried out chemical analyses of some metals to plot the metal profile of these potential reference areas and define basal levels of these metals in the soils. After examining the mutagenicity of the inorganic extracts using strains TA98, TA97a, and TA100, in the presence and absence of S9 mix, we indicated the São Jerônimo reference and the Itapuã reference as two sites that could be used in future studies of mutagenicity of soils in southern Brazil. The association between a mutagenicity bioassay and the “Ambient Background Concentration” seems to be a useful method to indicate the reference areas in studies of contamination by environmental mutagens, where these results were corroborated by canonical correspondence analysis.

A direct, general and efficient method to synthesize 2H-chromenes (2H-benzo[b]pyrans), identified as environmentally friendly pesticides, has been developed. This approach lays on the new concept of ecocatalysis, which involves the use of biomass from phytoextraction processes, as a valuable source of metallic elements for chemical synthesis. This methodology is similar or superior to known methods, affording 2H-chromenes with good to excellent yields (60–98 %), including the preparation of precocene I, a natural insect growth regulator, with 91 % yield. The approach is ideal for poor reactive substrates such as phenol or naphthol, classically transformed into 2H-chromenes by methodologies associated with environmental issues. These results illustrate the interest of combining phytoextraction and green synthesis of natural insecticides.