Samples were washed with tap water from the collecting sock into a 5 mm round stainless-steel sieve and then into a custom-made filtration apparatus consisting of a PVC tube, with a preweighted 315 μm nylon mesh attached to one end via hose clip. The pre-weighed filter containing the sample was then placed in a glass beaker and allowed to oven dry at 80°C until completely dry and the weight of the filter and sample was then recorded.