Two municipal waste incinerators in the vicinity of a residential area close to the city of Antwerp caused concern to local habitants. Risk assessment was performed combining chemical, toxicological measurements and model calculations. As the first step in risk assessment an inventory was made of historic emissions from both incinerators with emphasis on dioxins. The operational atmospheric transport and deposition model for priority substances (OPS) was used to calculate the deposition of dioxins in the vicinity of incinerators. The observed soil contamination pattern did not correspond to the calculated deposition pattern, indicating that other sources may contribute at least partly to the local PCDD/PCDF contamination of the area. Dioxin exposure of people in the Neerlandquarter as a function of the food consumption behavior was calculated using a mathematical model (VLIER-HUMAAN) combined with transfer factors. According to the results of these calculations, just residing in the impact area does not result in a meaningful risk. Only if locally produced food was consumed (milk, meat and vegetables), exposure in the Neerlandquarter was enhanced compared to the average dioxin exposure estimated for the Flemish population. Exposure in 1997 was below the exposure in 1980. As a consequence of different eating habits and lower bodyweight, children are subjected to significantly higher exposure than adults. Adverse health outcomes from dioxin exposure in the past cannot be excluded. There was no evidence for enhanced exposure to genotoxicants based on a comparison of chromosomal damage to blood cells of children from the study area to those from a control group.

Adolescent↗

PubMedDate not supplied

Controlling postoperative pain with patient-controlled analgesia.

Patient-controlled analgesia is an innovative method of pain control that is being used with increasing frequency in postoperative patients. Besides affording patients a sense of control over their pain, the method seems to offer superior pain relief with less sedation compared with traditional methods. Nurses report that valuable patient care time is saved when complicated negotiations among nurses, patients, and physicians regarding pain management are eliminated, and tasks such as signing out and preparing analgesic injections are no longer necessary. A review of the method is presented.

Analgesics↗

PubMedDate not supplied

Preclinical studies of dynamic treatment modes in pion therapy.

Preliminary results on a system for delivering dynamic pion radiotherapy treatments are reported. The desired treatment volume is scanned across a small, focused pion beam using a computer-controlled treatment couch. A computer-controlled rangeshifting device modulates the stopping pion depth distribution in coordination with the couch motion to conform the dose to the shape of the treatment volume. For certain shaped tumors, the system can result in substantial normal tissue dose sparing and better field flatness as compared to irradiation by static treatments with broad terms. The characteristics of this new system, plus preliminary results for typical dose distributions as measured with thermoluminescent dosimeters (TLDs), are presented.

Elementary Particles↗