Effects of primary- and secondary-treated bleached kraft mill effluents on the immune system and physiological parameters of roach.

The present study was designed to examine, whether, effluents from a modern pulp and paper mill using elemental chlorine-free/total chlorine-free (ECF/TCF) bleaching, exert effects on the immune system of fish and, in addition, to relate these findings to physiological parameters known to be affected by bleached kraft-mill effluents (BKME). Roach (Rutilus rutilus) were exposed in laboratory conditions to primary- or secondary-treated effluent from a pulp and paper mill. In order to study their capability to respond to foreign antigens they were immunised with bovine gamma-globulin (BGG) prior to exposure. The number of anti-BGG antibody-secreting cells (ASC) and the number of immunoglobulin-secreting cells (ISC) in the spleen and blood as well as the level of anti-BGG specific antibodies and concentration of plasma immunoglobulin (IgM) were studied. Phagocytosis and migration of granulocytes of the head kidney were also determined. In addition to the immunological parameters, the activity of hepatic biotransformation enzymes, the carbohydrate metabolism and osmoregulation were examined. Exposure of roach for 21 days to BKME affected several immunological parameters. Both effluents, primary- and secondary-treated, impaired the immunoreactivity of the fish. Sex-related differences in the immune responses were evident in many parameters e.g. in the number of blood ISC and splenic ASC. Sex also had effects on cortisol levels and in the induction of 7-ethoxyresorufin O-deethylase (EROD). These results demonstrate that both primary- and secondary-treated effluent from a pulp and paper mill using ECF/TCF bleaching have effects on fish immune functions. Further, these findings suggest that steroids may contribute to immunomodulation in fish.

Dentists' decisions as to mode of preventive treatment in adolescents and young adults in Finland.

OBJECTIVE: To evaluate dentists' real-life decisions as to mode of preventive treatment in adolescents and young adults, in relation to these patients' oral-health status, and to the dentists' characteristics. DESIGN: A random sample of 206 adolescents and 239 young adults (mean ages 13 and 27 years) produced 411 (92%) individual oral health records providing data on actual clinical examinations and treatment courses carried out by 56 dentists in one administrative unit of the Finnish public oral health service during 1994-1996. OUTCOME MEASURES: Preventive measures were defined as active and passive, active including any kind of motivation or instructions given to a patient concerning home self-care, and passive prevention being topical application of fluoride. RESULTS: More adolescents had received both active and passive prevention than had young adults (active: 27% vs. 20%; passive: 85% vs. 70%). Of adolescents, 7% and of young adults 25% were given no preventive treatment. The mean number of active preventive measures per adolescent during the treatment course was 0.3 and of passive measures 1.0; for young adults 0.2 and 0.8, respectively. A subject's oral health status made no significant difference in active prevention given. Active measures were more frequently given to all patients by male dentists, 35% vs. 22% (P < 0.02), and passive measures by females, 82% vs. 52% (P < 0.001). The odds of active prevention for adolescents were 7.4 comparing male dentists to female; of passive 13.8 comparing female to male. CONCLUSIONS: Dentists should be motivated to make considered treatment decisions on preventive treatment.