Polycyclic aromatic hydrocarbon-DNA adducts in beluga whales from the Arctic.

The Arctic is still relatively pristine in nature, but it is also vulnerable to pollution because contaminants originating from midlatitudes are transported to the Arctic by atmospheric processes, ocean currents, and rivers (Muir et al., 1992). Recognition of this fact of Arctic vulnerability has resulted in a Declaration on the Protection of the Arctic Environment by eight Arctic countries. A manifest aim of this declaration is to develop an Arctic Monitoring and Assessment Program. We report here on the presence of measurable levels of polycyclic aromatic hydrocarbon-DNA adducts, including relatively high levels in Arctic beluga (Delphinapterus leucas). These results lend support to the value of developing biological assessment programs for Arctic wildlife.

Bioaccumulation of aromatic hydrocarbons from sediments: a dose-response study with flounder (Pseudopleuronectes americanus).

Pseudopleuronectes americanus were chronically exposed to Hibernia crude oil in sediments, for 4 months. Oil was added to sediments at five concentrations between 0.09 and 4.5 mg/g (dry weight) and was 0.10-0.90 mg/g, at the termination of the exposure. Bioaccumulation measured in terms of fluorescence or in terms of the concentration of specific aromatic targets, increased with dosage. Accumulation of hydrocarbons was observed in muscle tissue (0.22 microgram/g, dry weight), when concentration of the sum of 27 polycyclic aromatic compounds (PAC) in sediments was of 0.65 microgram/g (E-50), at the end of the 4-month period. Of the 27 parental and alkylated polycyclic aromatic compounds analyzed, alkylated naphthalenes predominated in muscle (90-100%) and in sediments (30-60%). Bioaccumulation factors were derived for 13 compounds detected in muscle, at the three higher exposures. Liver concentrations (fluorescence) were higher than in muscle, but did not display a noticeable dose-response. Several alkylbenzenes, a C-2 biphenyl and C-4 acenaphthene were also detected in muscle extracts. The development of dose-response relationships for polycyclic aromatic hydrocarbons (PAH) present in sediment, in relation to bioaccumulation in flatfish, is of major interest for evaluating the environmental effects of oil contamination.

Review and perspective on the use of mixed-function oxygenase enzymes in biological monitoring.

It is often suggested that changes in simple biochemical/physiological responses may be useful for predicting the impacts of pollutants at population and community levels of biological organization. There are serious conceptual constraints to such a thesis and its seems likely that such simple responses can go no further than serving as early warning systems for delineating potential areas of pollutant impact--areas which (if shown to be significant in size) can then be subjected to more detailed population and community type studies. Environmental testing is a prerequisite for any response suggested to have value as a biological monitoring index and the induction of mixed-function oxygenase (MFO) enzymes has now been validated in a large number of field studies worldwide. Investigations have progressed from documenting induction near localized sources of hydrocarbon contamination to more diffuse sources of mixed organic pollution originating from industrial and domestic sources. Studies in the Great Lakes and Europe have demonstrated that the induction of MFO enzymes is a biological response of sufficient sensitivity to discriminate water quality differences over broad geographical areas. We suggest that as an early warning system, the induction of these enzymes can fulfill the requirement of "most sensitive biological response" for assessing a variety of organic pollution conditions. Given the high level of sensitivity of the MFO enzyme response, negative as well as positive field trials can be of value in addressing concerns about the toxicological significance of "high-profile" chemicals (and potent inducers) such as polycyclic aromatic hydrocarbons and organochlorines. MFO enzyme induction can also be an economical tool for environmental managers for reacting to real or perceived concerns about pollution such as effects on commercial fish stocks at sites of petroleum hydrocarbon development in the oceans.

Seasonal changes in aryl hydrocarbon hydroxylase activity of a marine fish Tautogolabrus adspersus (Walbaum) with and without petroleum exposure.

Organ indices and hepatic aryl hydrocarbon hydroxylase (AHH) were measured periodically from before gonad maturation to post-spawning on cunners (Tautogolabrus adspersus) (a) maintained in captivity, (b) maintained in captivity and treated continuously with 0.3-0.8 ppm crude oil accommodated in seawater and (c) sampled directly from the field population. Total (AHH) activity in field-sampled fish (normalized to 100 g body weight) decreased 166-fold in males and 155-fold in females from maximal values before gonad maturation to minimum values two weeks following spawning. Inducibility of AHH was suppressed during the period of minimum AHH activity but returned about 3 weeks after the end of spawning. Maximal mean AHH induction by exposure to crude oil observed during the study was 5.8-fold in males and 7.5-fold in females. Captive fish had smaller gonads in both sexes and reduced liver size in females relative to fish caught immediately before sampling. Petroleum exposure further inhibited the normal increase in gonad size in both sexes relative to an unexposed fish in addition to the inhibition due to captivity alone. Captive fish did not feed well and decreased in condition index; the oil exposed group was more affected than the control captive group.