Indoor and outdoor BTX levels in Barcelona City metropolitan area and Catalan rural areas.

Five aromatic hydrocarbons (benzene, toluene, and three isomeric xylenes) were monitored in indoor and outdoor air of 7 public buildings and 54 private homes, located in Barcelona City metropolitan area and in several rural areas of Catalonia. The sampling was carried out over four periods: spring-summer and winter of 2000, and summer and winter of 2001. Passive ORSA 5 Dräger samplers were used for benzene, toluene, and xylenes (BTX) adsorption. BTX were extracted with carbon disulphide and analysed using a gas chromatograph coupled to a FID detector. In Barcelona metropolitan area the outdoor average concentrations of BTX were 3.5, 34.2, and 31.3 microg/m3 in urban areas, and 1.4, 9.2, and 9.2 microg/m3 in rural areas, respectively. Average indoor air concentrations of BTX were respectively 4.3, 64.8, and 47.6 microg/m3 in urban areas and 5.8, 67.0, and 51.4 microg/m3 in rural areas, respectively. A direct connection between the house and garage was one of the most influential factors for indoor BTX concentrations in rural areas. In urban areas, diffuse traffic sources were the predominant BTX source, slightly influenced by tobacco smoke in indoor air.

Use of high-performance liquid chromatography to assess airborne mycotoxins. Aflatoxins and ochratoxin A.

An HPLC analytical method combining methanol-deionised water (80:20, v/v) extraction, methanol-acetonitrile (50:50, v/v) extraction and fluorescence detection was implanted to analyse ochratoxin A and aflatoxins B1, B2, G1 and G2 of air samples collected during the usual production process in a number of workplaces of a coffee factory to assess the occupational exposure of the engaged workers. The average levels of airborne ochratoxin A and aflatoxins were less than 1.2 and 0.4 ng/m3, respectively, using 50 L air samples. When 150 L air samples were used, levels lower than 0.04 ng/m3 ochratoxin A and 0.013 ng/m3 for aflatoxins B1, B2, G1 and G2, could be detected.

Determination of chlorpyrifos in air, leaves and soil from a greenhouse by gas-chromatography with nitrogen-phosphorus detection, high-performance liquid chromatography and capillary electrophoresis.

Chlorpyrifos was determined in air, leaves and soil in a greenhouse in order to establish performance differences between gas-chromatography with nitrogen-phosphorus detection (GC-NPD) and high-performance liquid chromatographic and capillary electrophoretic methods and to assess the farm workers' risk of overexposure due to air exposure and/or skin contact with this compound. Results obtained indicate that the three analytical techniques, with the specific procedures described, can be used, although only GC-NPD provides an operative limit of detection in air. Chlorpyrifos levels in air are dependent on time and greenhouse ventilation, whereas it remains for a long time on leaf surfaces and soil. As a consequence, specific instructions can be established for farm workers in order to avoid skin and respiratory exposure to chlorpyrifos.

Determination of DDT and related compounds in blood samples from agricultural workers.

An analytical method combining a solid-phase (C18) clean-up and GC-electron-capture detection using a capillary column, was implemented to determine p,p'-DDT and its metabolites (p,p'-DDD and p,p'-DDE), as well as other organochlorine pesticides in whole blood samples from 30 farmers and 24 non-occupationally exposed workers. The average concentrations for the quantified pesticides, p,p'-DDT, p,p'-DDD and p,p'-DDE, were 0.9, 1.5 and 8.0 micrograms/l whole blood for exposed workers and 0.3, 0.5 and 3.3 micrograms/l for unexposed workers, respectively. GC-MS was used to confirm the identity of the pesticides found. Solid-phase extraction and the protocol used give a cleaner analytical matrix, not only improving sensitivity and resolution, but also allowing analyses with smaller blood samples as compared to other methods.

Determination of chlorinated insecticides in blood samples of agricultural workers.

Lindane, aldrin and p,p'-DDT were determined in blood samples from 71 farmers by means of an analytical method which combines a direct whole-blood extraction with n-hexane and gas chromatography (GC)-electron-capture detection (ECD), using a capillary column, applied to the organic extract. This technique allowed the determination of pesticides at levels varying from 0.1 to 180 micrograms per l of blood, the detection limit for every pesticide being 0.1 microgram/l. GC-mass spectrometry was used to confirm the identity of each pesticide. The advantage of capillary column GC-ECD for pesticide determination is its sensitivity and high resolution, which makes it possible to separate pesticides from a complex n-hexane extract obtained in a very simple pretreatment of the blood sample, which is itself a very complex matrix.