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Background Approximately 2•8 billion people are exposed to household air pollution from cooking with polluting fuels. Few monitoring studies have systematically measured health-damaging air pollutant (ie, fine particulate matter [PM 2•5 ] and black carbon) concentrations from a wide range of cooking fuels across diverse populations. This multinational study aimed to assess the magnitude of kitchen concentrations and personal exposures to PM 2•5 and black carbon in rural communities with a wide range of cooking environments. Methods As part of the Prospective Urban and Rural Epidemiological (PURE) cohort, the PURE-AIR study was done in 120 rural communities in eight countries (

The search for effective materials for environmental cleanup is a scientific and technological issue of paramount importance. Among various materials, carbon nanotubes (CNTs) possess unique physicochemical, electrical, and mechanical properties that make them suitable for potential applications as environmental adsorbents, sensors, membranes, and catalysts. Depending on the intended application and the chemical nature of the target contaminants, CNTs can be designed through specific functionalization or modification processes. Designer CNTs can remarkably enhance contaminant removal efficiency and facilitate nanomaterial recovery and regeneration. An increasing number of CNT-based materials have been used to treat diverse organic, inorganic, and biological contaminants. These success stories demonstrate their strong potential in practical applications, including wastewater purification and desalination. However, CNT-based technologies have not been broadly accepted for commercial use due to their prohibitive cost and the complex interactions of CNTs with other abiotic and biotic environmental components. This paper presents a critical review of the existing literature on the interaction of various contaminants with CNTs in water and soil environments. The preparation methods of various designer CNTs (surface functionalized and/or modified) and the functional relationships between their physicochemical characteristics and environmental uses are discussed. This review will also help to identify the research gaps that must be addressed for enhancing the commercial acceptance of CNTs in the environmental remediation industry.

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The PM 10 and particles of greater than 10 µm aerodynamic diameter (hence forth referred as PM >10 ) collected over Delhi exceeded the National Ambient Air Quality Standards (100 µg m -3 ) with an annual average of 215 µg m -3 and 495 µg m -3 , respectively. The water soluble inorganic ions (WSII) were higher throughout the year in PM 10 (13.5%) than in PM >10 (5%). SO 4 2-dominated over NO 3 -ions and contributed 54% to the total WSII in PM 10 . NO 3 -and Ca 2+ were dominant ions in PM >10 . NH 4 + during winter and autumn, and Ca 2+ in summer PM 10 samples were the major acid neutralizing species. The WSII showed monthly and seasonal changes. The total carbon (TC = EC + OC) constituted 8.8%-47.8% of total PM 10 mass, and OC and EC varied from 9.91 to 37.06 µg m -3 and 5.42 to 22.23 µg m -3 during the year long sampling period. The SOC contributed more to OC in summers and the char (EC1) dominated over soot (EC2 + EC3) in EC fractions throughout the year. In summer samples, secondary OC (SOC) contributed 81% to OC and the OC/EC ratio was 3.61 suggesting the possible role of mineral dust and high photochemical activity in SOC production. For the eight different fractions, three dominant sources were identified, coal combustion, biomass burning, and motor vehicle exhaust for OC1, OC2 and OC3; vehicle exhaust for OC4, OP, EC2 and EC3; and biomass and coal combustion for EC1. The seasonal changes in the WSII and carbon concentrations in PM 10 and PM >10 are attributed to both the sources and the meteorological conditions in and around the study area.

SynopsisRed onion skin is highly effective for binding heavy metal ions from aqueous solutions. Color leaching can be prevented and the physical characteristics of the substrate can be improved by treatment with formaldehyde in an acidic medium. Batch and column experiments have been conducted with Cu2+, Cd2+, Zn2+, Ni2+, Hg2+, and Pb2+. Almost quantitative removal of the metal ions from solution can be achieved by using columns of the treated onion skin. Competition of the various metal ions for the substrate has been investigated. The capacity of the substrate in the majority of the metal ions studied is well above 1 meq/g. The use of polymerized onion skin to remove heavy metal ions from domestic and industrial wastewater to safe levels has been recommended as a cheap and effective alternative for commercial ion-exchange resins.

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