Suchergebnisse

During the burning of the organic material (firewood) in the drying, combustion may occur incompletely, thus generating smoke contaminants such as polycyclic aromatic hydrocarbons (PAHs) in the furnaces. This study aimed to identify possible contamination by PAHs in soybean grains from storage units in municipalities in the Midwest region that have undergone drying in a direct-fired furnace with firewood as fuel. The soybean grains were collected in different municipalities of the Midwest region of Brazil, totaling 22 samples. A survey of possible contamination of soybean grains by PAHs was carried out using High-Performance Liquid Chromatography. The experiment was carried out in a completely randomized design with three replicates, and the data were subjected to analysis of variance, with means compared by Tukey test. The sum of the groups was: PAH4 - 1.45 μg kg(−1) for Edéia (2), PAH8 - 2.97 μg kg(−1) for Catalão (19) and PAHT - 5.06 μg kg(−1) for Edéia (2); for benzo(a)pyrene, the sum was below 2.0 μg kg(−1), not exceeded by the value of 0.64 μg kg(−1) for Edéia (1). The values found of PAHs did not exceed the maximum limits established by the European Union, except for infant food.

Nitrated polycyclic aromatic hydrocarbons (nitro‐PAHs) constitute a group of substances formed during incomplete combustion. Sources include diesel vehicles, heating, smoking, certain types of food‐processing, and incomplete combustion in general. 2‐Nitrofluorene (NF) represents a model substance for the nitro‐PAHs. An attempt has been made to estimate the lifetime human cancer risk due to background exposure to nitro‐PAHs by two different models. The first model is based on genotoxic lesions produced by gamma‐irradiation and the second model is based on an earlier published mega study (24,000 animals) on the carcinogenicity of the major metabolite of NF. Both models agreed well‐representing a yearly human cancer risk in the range of 0.15–49 × 10−6 for an urban citizen. The weaknesses and strengths of the models are discussed.

Introduction: - Polycyclic aromatic hydrocarbons (PAHs) are a group of environmental carcinogens. They are formed during the incomplete combustion of organic matter. Humans are exposed to PAHs by various sources, including occupational environments, cigarette smoke, vehicle exhaust, and dietary sources as grilled and flame-broiled food. - In vivo studies in animals proved that PAHs are associated to cancer, and epidemiologic studies with exposed workers, especially in coke ovens and aluminium smelters, have shown clear excess of lung cancer and highly suggestive excesses of bladder cancer. - These compounds can enter in drinking water sources by precipitation and runoff on the earth's surface. - Portuguese legislation for water for human consumption (DL 306/2007) proposes the determination of five PAHs; limits of the maximum concentration are 0.10 µg/L for total BghiP, BbF, BkF, IcdP, and 0.010 µg/L for BaP. ; This work was financial suported by the COMPETE program, under the Watercork project (nº. 2009/552). ; N/A

AbstractAsset management plans were prepared in 1989 and 1994 by water companies in England and Wales for submission to the Office of Water Services. These plans constituted the financial programming required by water companies to meet specified standards of service, particularly with respect to water quality. Detailed studies have previously established that problems associated with iron from unlined ferrous mains, particularly in soft water areas, is often the main cost 'driver'for water distribution investment. However, many of the so‐called unlined iron mains were treated with a coal‐tar pitch lining for corrosion protection before installation, and residues of this painted lining can give rise to unsatisfactory levels of polycyclic aromatic hydrocarbons in drinking water.The paper describes how desk‐study research, followed by the development and application of a modified 'focused downstream series sampling'water‐quality modelling technique allowed polycyclic aromatic hydrocarbons to be accounted for in two water company asset management plan submissions. The paper also raises a number of fundamental implications with respect to the occurrence of these carcinogenic compounds in drinking water.