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This project will investigate:
<ul><li>transfer of persistent organic pollutants (POPs) from different types of recycled bedding to meat and eggs from chickens reared on recycled bedding</li>
<li>transfer of POPs into meat and liver from pigs reared on arable land previously treated with waste-derived fertiliser or liming agent</li></ul>
<p>The poultry module will be carried out in a highly controlled environment within a Good Laboratory Practice facility. Three representative recycled bedding products will be selected and characterised to determine concentrations of established and emerging POPs. Four groups of broilers will be reared for about 45 days on each of the three types of waste-derived bedding and under control conditions. Meat, skin/fat and liver samples will be analysed for POPs. Similarly, four groups of egg-laying hens will be reared on the three selected recycled bedding materials and under control conditions. Eggs will be collected from weeks 16 to 20, and meat, skin/fat and liver samples will also be collected from each group of hens. For the broilers and the egg-laying hens, the concentrations of various POPs found in each group of test samples will be compared with the corresponding control samples and transfer factors for uptake from waste bedding to meat, liver, skin/fat and/or eggs will be estimated.</p>
<p>Soil ingested by pigs reared outdoors is a source of contamination in meat and offal, so application of fertilisers containing contaminants could cause increased uptake of those contaminants by pigs reared on the treated land. For this project, an arable crop (eg barley) will be grown on four matching plots prior to rearing pigs on the land. Three of the plots will be treated with waste-derived soil conditioners (eg PLA, PSA, meat and bonemeal ash or biosolids) before growing and harvesting the crop and the fourth plot will serve as a control. Pigs will then be reared on each of these plots for about 20 weeks (ie until they are market-ready). Samples of meat and liver will be analysed and the levels of POPs present in tissues from each test group of pigs will be compared with the corresponding control samples. The transfer factors for the uptake of various contaminants by pigs from each type of waste-treated soil will be estimated. </p>
<p>Background: There is increasing pressure to minimize disposal of waste to landfill by recycling as much material as possible. Waste streams such as poultry litter ash (PLA) and sewage sludge (biosolids) are used as fertilisers on agricultural land, thus beneficially recycling scarce plant nutrients. Paper sludge ash (PSA) is an effective liming agent. Recycled waste wood shavings or shredded cardboard are increasingly being used as bedding for poultry and other livestock. However, these waste streams contain diverse chemical contaminants. These include various emerging organic contaminants, for which there is very little information concerning transfer to livestock exposed to recycled bedding or land amended with waste-derived soil conditioners. </p>
This project aims to:
<ul><li>generate robust scientific evidence, that poultry kept on recycled bedding, or pigs reared on land previously treated with waste-derived fertiliser or liming agent, will not present a risk to food safety</li>
<li>identify the level of control measures needed to protect the food chain</li></ul>