Assessment of human exposure to benzene through foods from the Belgian market

Benzene is a volatile organic compound known to be carcinogenic to humans (Group 1) and may be present in food. In the present study, 455 food samples from the Belgian market were analyzed for benzene contents and some possible sources of its occurrence in the foodstuffs were evaluated. Benzene was found above the level of detection in 58% of analyzed samples with the highest contents found in processed foods such as smoked and canned fish, and foods which contained these as ingredients (up to 76.21 μg kg⁻¹). Unprocessed foods such as raw meat, fish, and eggs contained much lower concentrations of benzene. Using the benzene concentrations in food, a quantitative dietary exposure assessment of benzene intake was conducted on a national representative sample of the Belgian population over 15 years of age. The mean benzene intake for all foods was 0.020 μg kg bw d⁻¹ according to a probabilistic analysis. These values are below the minimum risk level for oral chronic exposure to benzene (0.5 μg kg bw d⁻¹).     

Bioconversion of wastes from olive oil industries by vermicomposting process using the epigeic earthworm Eisenia andrei

The present work evaluates the possible bioconversion of wet olive cake by low-cost biostabilization (vermicomposting process). Wet olive cake fresh (WOC), precomposted (WOCP), or mixed with biosolids (WOCB), were vermicomposted for 6 months to obtain organic amendments for agricultural and remediation purposes. The results showed initial differences depending on previous treatment. WOCP was initially more stable, presented a low C:N ratio, and showed more dehydrogenase and urease activity. By contrast, there was no dehydrogenase activity initially in WOC and WOCB, due to the presence of some different types of polyphenols. Finally, the end product showed relatively higher amounts of total nitrogen and humic acid and met the standard of quality for composts and vermicomposts for use both in conventional and organic agriculture and soil-restoration programs.     

Photocatalytic elimination of indoor air biological and chemical pollution in realistic conditions

The photocatalytic elimination of microorganisms from indoor air in realistic conditions and the feasibility of simultaneous elimination of chemical contaminants have been studied at laboratory scale. Transparent polymeric monoliths have been coated with sol-gel TiO(2) films and used as photocatalyst to treat real indoor air in a laboratory-scale single-step annular photocatalytic reactor. The analytical techniques used to characterize the air quality and analyze the results of the photocatalytic tests were: colony counting, microscopy and PCR with subsequent sequencing for microbial quantification and identification; automated thermal desorption coupled to gas chromatography with mass spectrometry detection for chemical analysis. The first experiments performed proved that photocatalysis based on UVA-irradiated TiO(2) for the reduction of the concentration of bacteria in the air could compete with the conventional photolytic treatment with UVC radiation, more expensive and hazardous. Simultaneously to the disinfection, the concentration of volatile organic compounds was greatly reduced, which adds value to this technology for real applications. The fungal colony number was not apparently modified.     

Distribution of polychlorinated biphenyls in both products and by-products of a mussel shell incinerator facility

Purpose  

Solid waste incineration has recently attracted much attention because the combustion process involved produces highly toxic organohalogen contaminants such as dioxin-like polychlorinated biphenyls (DL-PCBs) present in fly ash. This has raised the need for simple, rapid, accurate methods for monitoring PCBs in ash samples.     

Overview of deaths associated with natural events, United States, 1979-2004.

Analysis of the National Center for Health Statistics' Compressed Mortality File showed that between 1979 and 2004, natural events caused 21,491 deaths in the United States. During this 26-year period, there were 10,827 cold-related deaths and 5,279 heat-related deaths. Extreme cold or heat accounted for 75 per cent of the total number of deaths attributed to natural events--more than all of deaths resulting from lightning, storms and foods, and earth movements, such as earthquakes and landslides. Cold-related death rates were highest in the states of Alaska, Montana, New Mexico, and South Dakota, while heat-related deaths were highest in the states of Arizona, Missouri, and Arkansas. These deaths occurred more often among the elderly and black men. Other deaths were attributed to lightning (1,906), storms and foods (2,741), and earth movements (738). Most deaths associated with natural events are preventable and society can take action to decrease the morbidity and mortality connected with them.     

Sequence-based source tracking of Escherichia coli based on genetic diversity of beta-glucuronidase

High levels of fecal bacteria are a concern for recreational waters; however, the source of contamination is often unknown. This study investigated whether direct sequencing of a bacterial gene could be utilized for detecting genetic differences between bacterial strains for microbial source tracking. A 525-nucleotide segment of the gene for beta-glucuronidase (uidA) was sequenced in 941 Escherichia coli isolates from the Clinton River-Lake St. Clair watershed, 182 E. coli isolates from human and animal feces, and 34 E. coli isolates from a combined sewer. Environmental isolates exhibited 114 alleles in 11 groups on a genetic tree. Frequency of strains from different genetic groups differed significantly (p < 0.03) between upstream reaches (Bear Creek-Red Run), downstream reaches, and Lake St. Clair beaches. Fecal E. coli uidA sequences exhibited 81 alleles that overlapped with the environmental set. An algorithm to assign alleles to different host sources averaged approximately 75% correct classification with the fecal data set. Using the same algorithm, the percent of environmental isolates assignable to humans decreased significantly between Bear Creek-Red Run (30 +/- 3%) and the beaches (17 +/- 2%) (p < 0.05). Birds accounted for approximately 50% of assignable environmental isolates. For combined sewer isolates, the same algorithm assigned 51% to humans. These experiments demonstrate differences in the frequency of different E. coli strains at different locations in a watershed, and provide a "proof in principle" that sequence-based data can be used for microbial source tracking.     

Evaluation of biotechnological processes to obtain ethanol from recycled paper sludge

Journal of Material Cycles and Waste Management - Finding innovative solutions to manage waste and to expand the production of biofuels are some of the current challenges. Pulp and paper sectors,...     

A knowledge network to promote the use and valorization of wild food plants in the Pantanal and Cerrado,Brazil

Regional Environmental Change - The conservation and use of wild food plants should include local people in the decision-making process, and many countries have done so. However, interacting with...     

Foraging ants trade off further for faster: use of natural bridges and trunk trail permanency in carpenter ants

Trail-making ants lay pheromones on the substrate to define paths between foraging areas and the nest. Combined with the chemistry of these pheromone trails and the physics of evaporation, trail-laying and trail-following behaviours provide ant colonies with the quickest routes to food. In relatively uniform environments, such as that provided in many laboratory studies of trail-making ants, the quickest route is also often the shortest route. Here, we show that carpenter ants (Camponotus rufipes), in natural conditions, are able to make use of apparent obstacles in their environment to assist in finding the fastest routes to food. These ants make extensive use of fallen branches, twigs and lianas as bridges to build their trails. These bridges make trails significantly longer than their straight line equivalents across the forest floor, but we estimate that ants spend less than half the time to reach the same point, due to increased carriage speed across the bridges. We also found that these trails, mainly composed of bridges, are maintained for months, so they can be characterized as trunk trails. We suggest that pheromone-based foraging trail networks in field conditions are likely to be structured by a range of potentially complex factors but that even then, speed remains the most important consideration.     

Mass balance in the monitoring of pollutants in tidal rivers of the Guanabara Bay, Rio de Janeiro, Brazil

This study addressed the identification and monitoring of pollution sources of terrestrial origin in rivers (domestic sewage and industrial effluents) and critical fluvial segments in highly polluted environments under tidal influence (mixing marine and continental sources) from Guanabara Bay Basin, Rio de Janeiro, Brazil. The mass balance of contaminants was determined in conditions of continuous flow (low tide) during dry season (lower dilution capability). The results allowed the evaluation of the potential of contaminant mass generation by the different river segments and the estimation of their natural and anthropogenic components. The water quality of Igua?ú and Sarapuí Rivers were evaluated for metals and biochemical oxygen demand. The method gave an excellent response, including the possibility of sources identification and contaminated river segments ranking. The approach also offers fast execution and data interpretation, being highly efficient.