Pierce, RC; Mathur, SF; Williams, DT; Boddington, MJ
Studies have shown that phthalate esters traverse the food web and can be found as the original ester in fish. However, concentrations are not expected to be magnified across the food web to a great extent since fish appear more capable of F degrading them than do in- vertebrates. Under conditions of continuous exposure, respiratory and dietary factors influence phthalate ester accumulation. Effects: Lethality: One of the major problems in testing the biological effects of phthalate esters in aqueous systems is their initial or sustained solubility in water The methodological details given in the studies reported allow few definitive statements concerning the actual ester concentrations used. Six phthalate esters have been studied for lethality, detailed studies for most of the organisms involved only DnBP. Lethal concentrations (LC50) for all the aquatic or- ganisms investigated range from 1 to 10 mg/1. The only noted lethal threshold is at a DnBP concentration of 0.5 mg/1 for rainbow trout (Salmo gairdneri). The data on the lethality of dimethylphthalate (DMP), diethylphthalate (DEP) and din-propylphthalate (DnPP) seem generally to fall within the same range as that for DnBP. In contrast, the values for DEHP lethal concentrations (LC50) are at least an order of magnitude higher than those for DnBP. The data for di-n-octylphthalate (DnOP) suggest that it is even less toxic than DEHP. Studies on the mortality of aquatic organisms exposed chroni- cally to phthalate esters are limited in number and difficult to interpret. The data for DnBP indicate that no threshold exists. Several effects of phthalate esters have been reported to occur at what may be considered an acutely lethal range of concentrations. Such effects cannot be truly classified as sublethal but are most probably manifestations of toxicity prior to actual death. Hence, effects such as suppression of respiration, failure of reproduction and survival of young, growth impairment,and depression of heartbeat, although usually considered as sublethal effects, were noted in experiments using acutely lethal concentrations of phthalate esters. Although the mechanisms are not known, DnOP, DEHP and di-iso-butylphthalate (DiBP) were found to suppress respira- tion in a soil not preincubated with phthalate esters. However, soil that had been preincubated did not undergo respiration suppression even at very high ester con- centrations. No variation in either the number of species of microorganisms or other responses, such as respiration, was found after the introduction of DEHP, phthalic acid, or 2-ethylhexanol into an intermittent flow-through hydrosoil. The number of larvae of brine shrimp (Artemia salina) hatched over 24 hours was reduced by 20 and 40 percent because of DEP and DnBP, respectively. No reduction was caused by DMP. There was a sufficient dosage (either in concentration or time) of these phthalate esters to allow for significant mortality in the early-hatching larvae. It has been reported that dietary phthalate esters have an effect upon the survival of zebrafish (Brachydamio rerio) fry. However, it is unclear whether the reduction in survival was due to the parent or the fry feeding on the DEHP in the diet. In addition, the variation in spawns and eggs per spawn may have been within the expected range of the species and the relationship to DEHP concentration was probably coincidental. The only studies that have examined the effects of phthalate esters on growth were carried out with some micro- organisms. The concentrations that inhibit growth are high, been shown to act as heartbeat depressors in goldfish (Cra- ssius auratus). Reductions of approximately 60% were recorded for 12 mg/l DnBP and 200 mg/l benzylbutylphthalate (BBP), respectively. A reduction of 33% was recorded for 200 mg/l DEHP. Sublethal Effects: Very little information is available on the sublethal effects of phthalate esters on aquatic organisms. Depression of reproduction in the water flea (Daphnia magna) has been observed. Di-(2-ethylhexyl)phthalate, in concentrations of 3, 10 an 30 ug/l, reduced egg laying over a 3-week period by 60, 70 and 80% respectively. The growth of rainbow trout fry, adult brook trout (Sulvelinus fontinalis) and fathead minnow fry was not sig- nificantly affected when the fish were exposed to low levels of DEHP; however, vertebral collagen content of bone and hydroxylproline content of collagen were altered. Steroid hormone biosynthesis in male Atlantic cod (Gradus morhus) was affected by DEHP at concentrations as low as 1 ug/g of tissue. The present criteria describing the sublethal effects of phthalate esters on aquatic organisms do not form an adequate scientific base on which to develop water quality objectives for the protection of aquatic life. (Shortened)
ANIMAL; HUMAN; Case report; irritancy; toxicokinetics; genetic toxicity; occupational exposure; Cosmetics; Eye; Skin; reproductive and developmental tests; ENVIRONMENT; AQUATIC TOXICITY; fish; invertebrate; algae; microorganisms; ENVIRONMENTAL CONCENTRATIONS; air; water; soil/sediment; biota; BIOACCUMULATION; aquatic; DEGRADATION; MOBILITY