Investigation into the formation of PAHs in foods prepared in the home to determine the effects of frying, grilling, barbecuing, toasting and roasting.

The effects of frying, grilling, barbecuing, toasting and roasting on the formation of 27 different PAHs in foods were investigated. A total of 256 samples from in-house cooking experiments were produced. There was little evidence of PAH formation during the grilling, frying, roasting and toasting experiments. Comparison with the raw materials used in the experiments showed little or no increase in PAH concentrations for all of the sample types, regardless of distances from the heat source, cooking mediums and intensity of cooking conditions. Barbecuing with charcoal plus wood chips however resulted in the formation of benzo[a]pyrene in most foods; for beef burgers only, barbecuing over charcoal (without the use of wood chips) gave the highest levels. In general PAH levels increased when the food was barbequed closer to the heat source. For sausages cooked over briquettes, and for beef burgers, beef and salmon cooked over charcoal, the concentration of PAHs was lower when the food was closer to the heat source. Cooking time may result in a moderate increase of PAHs in some foods, although concentrations in beef burgers appeared to fall when cooking time was extended by 50-100%.

Dioxins and polychlorinated biphenyls (PCDD/Fs and PCBs) in food from farms close to foot and mouth disease animal pyres.

To control the outbreak of foot and mouth disease, which occurred in the UK in early 2001, a large number of farm animals were slaughtered. Where it was not possible to render or landfill the carcasses, they were destroyed by burning on open pyres, with wood, coal and other materials. Uncontrolled combustion such as this is known to produce small quantities of dioxins and an investigation was made into whether, as a result of the burning, there was an elevation in the concentrations of these compounds in food produced in the areas close to the pyres. With few exceptions, concentrations of PCDD/Fs and PCBs were within the expected ranges as predicted by reference data. No accumulation over time was evident from a repeat milk sampling exercise. Where elevated concentrations of PCDD/Fs and PCBs were found in chickens and eggs, they were in samples not destined for the food chain. Elevated levels in some samples of milk from Dumfries and Galloway were not found in earlier or later samples and may have been found as a result of a temporary feeding regime. Elevated concentrations in lamb from Carmarthenshire were from very young animals which would not have entered the food chain. There was no evidence of any significant increase in dietary exposure to PCDD/Fs and PCBs as a result of the FMD pyres.