Dioxin emission factors for the incineration of different medical waste types

Previous research works showed that to protect public health, hospital incinerators should be provided with equipment to reduce atmospheric emissions. Most hospital incinerators do not possess such equipment, so efficient methodologies should be developed to evaluate the safety of incineration procedures. Emission factors can be used for an easy estimation of the parameters defined in legislation. Nevertheless, the actual knowledge is very scarce, mainly because previously published emission factors do not include enough information about the incinerated waste types and the respective proportion in incinerated mixture. The existence of different waste classifications also reduces the usefulness of previously published results. This study reports the first dioxin emission factors estimated for the incineration of medical waste, segregated in different types according to the classification of the Portuguese legislation. The main purpose was to evaluate the influence of waste type on emission factors, assessing how useful they are if not associated to the composition of the incinerated mixture. The study also allowed analyzing the correspondence between different waste classifications that are being used, comparing the estimated emission factors with the sole results previously published for specific waste types but segregated according to a different classification. The influence of the incinerated waste type and segregation practices on the concentration and amount of emitted dioxin was assessed, as well as the influence of segregation practices on the amount of wastes that must be incinerated. To estimate eventual hazards for human health, dioxin concentrations in combustion gas flow were compared with the respective legal limits.