Åke Larsson

Environmental and health hazard ranking and assessment of plastic polymers based on chemical composition.

Plastics constitute a large material group with a global annual production that has doubled in 15 years (245 million tonnes in 2008). Plastics are present everywhere in society and the environment, especially the marine environment, where large amounts of plastic waste accumulate. The knowledge of human and environmental hazards and risks from chemicals associated with the diversity of plastic products is very limited. Most chemicals used for producing plastic polymers are derived from non-renewable crude oil, and several are hazardous. These may be released during the production, use and disposal of the plastic product. In this study the environmental and health hazards of chemicals used in 55 thermoplastic and thermosetting polymers were identified and compiled. A hazard ranking model was developed for the hazard classes and categories in the EU classification and labelling (CLP) regulation which is based on the UN Globally Harmonized System. The polymers were ranked based on monomer hazard classifications, and initial assessments were made. The polymers that ranked as most hazardous are made of monomers classified as mutagenic and/or carcinogenic (category 1A or 1B). These belong to the polymer families of polyurethanes, polyacrylonitriles, polyvinyl chloride, epoxy resins, and styrenic copolymers. All have a large global annual production (1-37 million tonnes). A considerable number of polymers (31 out of 55) are made of monomers that belong to the two worst of the ranking models five hazard levels, i.e. levels IV-V. The polymers that are made of level IV monomers and have a large global annual production (1-5 million tonnes) are phenol formaldehyde resins, unsaturated polyesters, polycarbonate, polymethyl methacrylate, and urea-formaldehyde resins. This study has identified hazardous substances used in polymer production for which the risks should be evaluated for decisions on the need for risk reduction measures, substitution, or even phase out.

Fish physiology and metal pollution: results and experiences from laboratory and field studies.

Physiological methods, previously used as health indicators in laboratory investigations on fish exposed to toxicants, have been applied to feral fish living in metal-polluted waters. A background to the use of a physiological approach for detecting early-arising effects of toxic chemicals on fish is given, together with a description of the clinical parameters used and their physiological relevance. The results and experiences from the field application show that certain clinical methods may be very useful in detecting and diagnosing sublethal disturbances in natural fish populations in polluted areas. Furthermore, the results indicate a good agreement between metal-induced physiological effects detected in fish exposed under natural field conditions and those found in laboratory experiments.

Metabolic effects of starvation in the eel, Anguilla anguilla L.

Abstract 1. 1. The effects of starvation on different metabolites in blood, liver and muscle were studied in eels ( Anguilla anguilla L.) after 8, 95 and 145 days. 2. 2. During the first 95 days the eels apparently tended to utilize liver triglycerides as energy source. An increased liver glutamate oxaloacetate transaminase activity and maintenance of glycogen levels suggested a stimulated gluconeogenesis. 3. 3. Between 95 and 145 days the eels utilized great amounts of both liver and muscle triglycerides. There was also a marked decrease in liver glycogen during this later phase of starvation. 4. 4. The starvation also resulted in a significant decrease in blood glucose both after 95 and after 145 days.

Metabolic and hematological effects of starvation in the European eel, Anguilla anguilla L.—I. Carbohydrate, lipid, protein and inorganic ion metabolism

Abstract 1. The effects of starvation on different metabolities in blood, liver and muscle and the level of cortisol and some inorganic ions in plasma were studied in eels, Anguilla anguilla L., after 11, 47, 96 and 164 days. 2. During the first 96 days the eels apparently used mainly liver and muscle triglycerides and this utilization was accompanied by an increase in water content. 3. Between 47 and 96 days the levels of blood glucose and muscle glycogen increased followed by a decrease. 4. Between 96 and 164 days there was a marked decrease in liver glycogen and plasma protein while the triglyceride and water content of liver and muscle was unaffected. 5. The alterations in cholesterol and phospholipids and the possible role of LCAT (lecithin:cholesterol acyltransferase) in the regulation of these parameters is discussed. 6. During the entire starvation period the level of inorganic phosphate in blood plasma decreased and the level of blood lactate, plasma sodium and plasma cortisol increased. 7. The plasma chloride initially decreased followed by an increase after 96 days. These alterations in plasma chloride are discussed in relation to hematological studies and the level of plasma protein.

Disturbed ion balance in flounder, Platichthys flesus L. exposed to sublethal levels of cadmium

Abstract The ion balance in the flounder ( Ptatichthys flesus L.) was studied after 4 and 9 wk of exposure to sublethal cadmium levels (5–500 μg Cd/l) in brackish water. The cadmium exposure had no effect on the major blood plasma electrolytes, sodium and chloride, indicating an intact osmoregulation. In contrast, cadmium seriously affected the regulation of other ions. Potassium and calcium concentrations showed a strong and dose-dependent depression in blood plasma, whereas the plasma concentrations of inorganic phosphate and magnesium were significantly elevated. It is suggested that these ion disturbances might be associated with cadmium-induced pathological changes in ion-regulating tissues. The reduced concentrations of plasma calcium and potassium might be responsible for neuromuscular disturbances, such as hyperexcitability, spasms and tetanic body contractions, observed in some flounders exposed to the highest cadmium concentration (500 μg Cd/l). In spite of the pronounced disturbance of the calcium metabolism, the spinal columns of the cadmiumexposed flounders did not show any signs of demineralization, fractures or other deformations. This might be due to the fact that the flounder probably has an acellular bone tissue, which only to a small degree seems to be affected by the disturbed calcium balance. It is suggested that fish species with acellular bone tissue run a minor risk of suffering from skeletal damage after cadmium exposure than fish species with an active cellular bone tissue.

The effect of cadmium on the hematology and on the activity of δ-aminolevulinic acid dehydratase (ALA-D) in blood and hematopoietic tissues of the flounder, Pleuronectes flesus L.

Flounders (Pleuronectes flesus) were exposed to sublethal levels of cadmium (5, 50, and 500 micrograms of Cd2+/liter) for periods of 4 and 9 weeks, and the hematological response as well as the effect on the activity of delta-aminolevulinic acid dehydratase (ALA-D) in blood and blood-forming tissues were investigated. Significant reductions of hematocrit, hemoglobin, and red blood cell count were found in the cadmium-exposed fish. This anemic response was apparent even in flounders exposed to the lowest cadmium concentration, approximately corresponding to 1/4000 of the 96-hr LC50 value. The anemia was accompanied by a significant increase of the ALA-D activity in renal tissues. This indicates a compensatory stimulation of the introductory steps of the hemoglobin biosynthesis. However, the formation of hemoglobin does not seem to be accomplished, which might be due to a disturbed iron metabolism. The cadmium exposure also resulted in a significant increase of the number of lymphocytes, indicating an action on the immunological defense of the fish.

Long-term sublethal physiological effects on rainbow trout, Salmo gairdneri, during exposure to cadmium and after subsequent recovery

Abstract The effects on hematology, blood plasma ion balance and carbohydrate metabolism were studied in rainbow trout, Salmo gairdneri, kept in brackish water, and after 18 and 30 wk of exposure to sublethal levels of cadmium (10 and 100 μg Cd/liter), after 25 and 57 wk of subsequent recovery in clean water. Cadmium exposure caused anemia, hypocalcemia and hypermagnesemia. These effects have previously been observed in fish during shorter periods of exposure, but disappeared in the present study within 25 wk of recovery. This suggests that it is the presence of free cadmium ions during the exposure that is responsible for most of the hematological and biochemical effects. Contrary to these findings, the hyperglycemia, that was present during the exposure, persisted throughout the recovery period. Further evidence for a disturbed carbohydrate metabolism after cessation of the exposure was indicated by a dose-dependent decrease in muscle glycogen content after 25 wk of recovery, and by a dose-dependent increase in liver glycogen content after 57 wk of recovery. These effects on the carbohydrate metabolism could be mediated via the selective uptake of cadmium ions in the pancreas and an inhibitory effect on the insulin secretion, thus resulting in an abnormal endocrine control of the metabolism. Analyses of cadmium revealed a dose-dependent accumulation of cadmium in the muscle, that had reached equilibrium after 18 wk of exposure, while a continuing and dose-dependent accumulation was found in the liver throughout the exposure. The levels attained in the liver were about 100 times higher than in the muscle. The slow elimination from liver and kidney suggest a biological half-life for cadmium of more than 1 yr in these tissues. A close positive correlation was found between cadmium levels in liver and in kidney (r = 0.90) in fish after 57 wk of recovery.

Metabolic effects of technical pentachlorophenol (PCP) on the eel Anguilla anguilla L.

Abstract 1. 1. Eels ( Anguilla anguilla L.) were exposed to sea water and fresh water containing 0·1 ppm pentachlorophenol (PCP). The accumulation of the pesticide as well as the effects on different metabolites in blood, muscle and l liver were studied. 2. 2. PCP exposure caused changes, which indicated a hypermetabolic state with accelerated utilization of tissue energy reserves. 3. 3. An altered cholesterol metabolism, a decreased activity of liver glutamate pyruvate transaminase (GPT) and an enlargement of the liver suggested a disturbed liver function. 4. 4. The effects of PCP seemed to persist in spite of a recovery period in clean water for about 2 months.

Biotransformation enzyme activities and histopathology in rainbow trout Salmo gairdneri, treated with cadmium

Abstract The effects of intraperitoneal administration of cadmium and exposure to cadmium in the water on rainbow trout, Salmo gairdneri , were studied. The results of intraperitoneal injection of cadmium indicate that this metal has the potential to inhibit phase I and phase II xenobiotic biotransformation activities in the liver and kidney. The exposure to cadmium through water resulted in different responses in the liver and kidney. The marked inhibition of the glucuronidation reaction is of toxicological importance, since this may potentiate the toxic action of organic xenobiotics biotransformed through this pathway. This response in the kidney was accompanied by histopathological changes in the proximal renal tubules, which are probably associated with the plasma hypocalcaemic response observed in cadmium-poisoned fish.

Cholesterol and free fatty acids (FFA) in the blood of marine fish.

Abstract 1. 1. The contents of cholesterol and free fatty acids (FFA) in blood plasma were examined in 22 species of marine fishes caught in the Skagerrak and representing various groups of fishes (Cyclostomi, Holocephali, Elasmobranchii and Teleostei). 2. 2. The cholesterol level in most fishes, except elasmobranchs, was 2–6 times higher than that of higher vertebrates. In the majority of examined fish species 65–75% of the plasma cholesterol was in esterified form. 3. 3. A seasonal variation in plasma cholesterol, probably associated with spawning, was found in the teleosts Gadus virens and Gadus morrhua . 4. 4. The plasma FFA level, which showed great interspecies variation, seemed to be dependent both on storage sites of lipid reserves and on the activity of the fish species. 5. 5. Various factors affecting the blood plasma levels of cholesterol and FFA in fish are reviewed.