Estimation of the environmental contamination by phthalic acid esters leaching from household wastes

Phthalic acid esters (PAE) have been used as plasticizers in many products. Here we estimate the contaminating potential of PAE codisposed with domestic wastes. In order to determine the maximum threat to the environment, we analysed several fractions of different household wastes. A maximum of 2.6% of di-(2-ethylhexyl) phthalate (DEHP) was measured in ‘compound materials’. More than 90% of all the PAE present in the refuse was due to DEHP. Assuming defined compositions of the refuse we calculated that approx. 1 kg of phthalate esters per ton of dry waste may be codisposed. The actual amount of PAE that could be eluted by the leachate was estimated using laboratory bioreactors which were filled with waste of exactly known composition. Only approx. 1 g of PAE per ton of dry waste was leached. However, the elution of hydrophobic DEHP by the leachate is dependent on the composition of the waste which gave rise to different concentrations of dissolved organic carbon. Because of the experimental setup the amounts of leached PAE represent minimum levels of possible environmental contamination. Hence, there will be a constant output of PAE from unlined municipal landfills for decades.