Bottom trawling resuspends sediment and releases bioavailable contaminants in a polluted fjord.

Sediments are sinks for contaminants in the world's oceans. At the same time, commercial bottom trawling is estimated to affect around 15 million km(2) of the world's seafloor every year. However, few studies have investigated whether this disturbance remobilises sediment-associated contaminants and, if so, whether these are bioavailable to aquatic organisms. This field study in a trawled contaminated Norwegian fjord showed that a single 1.8 km long trawl pass created a 3-5 million m(3) sediment plume containing around 9 t contaminated sediment; ie. 200 g dw m(-2) trawled, equivalent to c. 10% of the annual gross sedimentation rate. Substantial amounts of PCDD/Fs and non-ortho PCBs were released from the sediments, likely causing a semi-permanent contaminated sediment suspension in the bottom waters. PCDD/Fs from the sediments were also taken up by mussels which, during one month, accumulated them to levels above the EU maximum advised concentration for human consumption.

Psychotic patients' attributions for mental illness.

The study examined the attributions concerning mental illness of young psychotic out-patients participating in a rehabilitation programme. The sample consisted of 50 men and 33 women (mean age 26 yrs) diagnosed by their treating psychiatrist as psychotic, with main symptoms: hallucinations (59 per cent), depression (12 per cent), non-specific (29 per cent). Subjects replied to a personally administered questionnaire, designed to obtain ratings of importance for several causes of mental illness, and a measure of how optimistic they felt about their future psychological health. Factor analysis of the subjects' ratings revealed three factors: 'Family - Relationships', 'Personal Inadequacy' and 'Chance', accounting for 48 per cent of the variance. Except for gender, demographic variables (age, educational level, social class) and variables specific to the sample in question (type of symptoms, length of participation in the programme) did not differentiate significantly subjects' beliefs about their illness. However, the findings suggest that lower ratings of personal inadequacy may be associated with increased optimism about subjects' future mental health.