AOX — Emiissions from hospitals into municipal waste water

Adsorbable organically bound halogens (AOX) are mostly persistent in the environment, and accumulate in the food web. Some of them are toxic to humans and other organisms. AOX were measured in the effluents from six German hospitals of different size and departments like internal medicine and ear-nose and throat (ENT) as well as from laundry, kitchen and laboratory. The concentrations in the day time mixed samples of the total effluent were 0.13 mg l−1 − 0.94 mg l−1 ( = 0.43 mg l−1). For the separately investigated departments the lowest concentrations were found in the effluent from laundry and kitchen (0.015 mg l−1), and the highest ones in the effluents from the medical departments (0.12 – 1.71 mg l−1, 0.95 mg l−1 during the week and 0.06 – 0.10 mg l−1 at the week-end) and the laboratories (0.05–14.2 mg l−1, 2.73 mg l−1). The AOX concentration in night time mixed samples were 0.07 – 0.41 mg l−1 ( = 0.41 mg l−1) for the total effluents and 0.25 – 2.64 mg l−1 ( = 1.11 mg l−1) for medical departments. Concentrations expected by computing the input of AOX attributable to pharmaceuticals were between 11% and 16% for two hospitals and 7.7% for an ENT department. One additional important source of AOX in hospital effluents may be x-ray contrast media containing a iodine carbon bond.