During the last three decades, the impact of chemical pollution has focused almost exclusively on the conventional "priority" pollutants, especially those acutely toxic/carcinogenic pesticides and industrial intermediates displaying persistence in the environment. This spectrum of chemicals, however, is only one piece of the larger puzzle in "holistic" risk assessment. Another diverse group of bioactive chemicals receiving comparatively little attention as potential environmental pollutants includes the pharmaceuticals and active ingredients in personal care products (in this review collectively termed PPCPs), both human and veterinary, including not just prescription drugs and biologics, but also diagnostic agents, "nutraceuticals," fragrances, sun-screen agents, and numerous others. These compounds and their bioactive metabolites can be continually introduced to the aquatic environment as complex mixtures via a number of routes but primarily by both untreated and treated sewage. Aquatic pollution is particularly troublesome because aquatic organisms are captive to continual life-cycle, multigenerational exposure. The possibility for continual but undetectable or unnoticed effects on aquatic organisms is particularly worrisome because effects could accumulate so slowly that major change goes undetected until the cumulative level of these effects finally cascades to irreversible change--change that would otherwise be attributed to natural adaptation or ecologic succession. As opposed to the conventional, persistent priority pollutants, PPCPs need not be persistent if they are continually introduced to surface waters, even at low parts-per-trillion/parts-per-billion concentrations (ng-microg/L). Even though some PPCPs are extremely persistent and introduced to the environment in very high quantities and perhaps have already gained ubiquity worldwide, others could act as if they were persistent, simply because their continual infusion into the aquatic environment serves to sustain perpetual life-cycle exposures for aquatic organisms. This review attempts to synthesize the literature on environmental origin, distribution/occurrence, and effects and to catalyze a more focused discussion in the environmental science community.

Pharmaceuticals and personal care products in the environment: agents of subtle change?

Publisher Summary Mangroves are trees or bushes growing between the level of high water of spring tides and a level close to but above mean sea-level Very few species of mangrove are deep rooted, or have persistent tap roots Almost all are shallow rooted but the root systems are often extensive and may cover a wide area Rhizophoraceous trees have seedlings with a long radicle which would seem well suited to develop into a tap root, but as soon as the seedling becomes established in the mud the radicle develops little further Trees of Avicennia and of Sonneratia develop several different kinds of roots The main rooting system consists of large cable roots which give off anchoring roots downwards and aerial roots or pneumatophores upwards These pneumatophores in their turn produce a large number of nutritive roots which penetrate the mineral-rich subsurface layers of the soil The land animals found in mangrove forests include roosting flocks of fruit bats, fishing and insectivorous birds, and many insects are conspicuous Of the marine animals, crabs and molluscs live permanently in the forest, and prawns and fishes come in on the tide to feed on the apparently abundant nutriment provided by the mangrove soils In South East Asia man uses mangrove areas for the establishment of ponds for the culture of fish and prawns, and for timber

A General Account of the Fauna and Flora of Mangrove Swamps and Forests in the Indo-West-Pacific Region

Osmotic and ionic regulation

Polychlorinated biphenyls (PCBs) as environmental contaminants often cannot be adequately described by reference to Aroclors or to total PCBs. Although there are 209 possible PCB configurations (congeners), perhaps half that number account for nearly all of the environmental contamination attributable to PCBs. Still fewer congeners are both prevalent and either demonstrably or potentially toxic. If potential toxicity, environmental prevalence, and relative abundance in animal tissues are used as criteria, the number of environmentally threatening PCB congeners reduces to about thirty-six. Twenty-five of these account for 50 to 75% of total PCBs in tissue samples of fish, invertebrates, birds, and mammals. A few PCB congeners that are sterically similar to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) are directly toxic. Other PCB congeners, as well as those that are directly toxic, may also be involved in toxicity indirectly by stimulating the production of (inducing) bioactivating enzyme systems. The most consequential of these have the ability to induce aryl hydrocarbon metabolizing mixed-function oxidases (MFOs). A result can be an increased capacity for bioactivation of otherwise nontoxic foreign compounds such as certain polynuclear aromatic hydrocarbons (PAH) to cytotoxic or genotoxic metabolites. The effectiveness of specific PCB congeners as inducers of different types of cytochrome P-450-dependent MFO systems is determined by their stereochemistry. Although MFO induction is not a proximate cause, it is a strong correlate of certain kinds of toxicities. Structural patterns can thus be used to discriminate among PCB congeners on the basis of toxic potential, if not entirely on toxicity per se. Congeners that demonstrate 3-methylcholanthrene-type (3-MC-type) and mixed-type MFO induction have the greatest toxic potential. These congeners most closely resemble 2,3,7,8-TCDD in their structures and in their toxic effects. The larger group of phenobarbital-type (PB-type) inducers have considerably less potential for contributing to toxic effects. Weak inducers and noninducing congeners have the least potential for toxicity. Using the rationale described in this paper, we assigned the most evironmentally threatening PCB congeners to four groups. Congeners assigned to Group 1 are considered most likely to contribute to adverse biological effects attributable to PCBs in an environmental sample. Group 1A contains the three most potent (pure 3-MC-type inducer) congeners, IUPAC numbers 77, 126, and 169. Six congeners, numbers 105, 118, 128, 138, 156, and 170, are assigned to Group 1B. These congeners are mixed-type inducers that have been reported frequently in environmental samples.(ABSTRACT TRUNCATED AT 400 WORDS)

Environmental occurrence, abundance, and potential toxicity of polychlorinated biphenyl congeners: considerations for a congener-specific analysis.

This article reviews the field and laboratory evidence for endocrine disruption in gastropod mollusks caused by tributyltin (TBT). Abundant and undisputed field data link TBT with an irreversible sexual abnormality of female neogastropod snails known as “imposex.” This phenomenon is a masculinization process involving the development of male sex organs, notably a penis and a vas deferens; in certain species the imposition of a vas deferens disrupts oviducal structure and function, preventing normal breeding activity and causing population disappearance. In some species, oogenesis is supplanted by spermatogenesis. A related condition referred to as “intersex” has been reported in littorinid mesogastropods, and these too become unable to lay eggs. Field evidence clearly associates these syndromes with the use of TBT as an antifoulant, chiefly on boat hulls, and dose-related effects can be replicated in laboratory exposures to environmentally relevant concentrations of TBT compounds. It has now been established that imposex and intersex are forms of endocrine disruption caused by elevated testosterone titers that masculinize TBT-exposed females. The precise mechanism by which increased levels of testosterone are produced has not been fully described, but the weight of evidence suggests that TBT acts as a competitive inhibitor of cytochrome P450-mediated aromatase. Some recent data suggest that TBT may also inhibit the formation of sulfur conjugates of testosterone and its active metabolites, thus interfering with its excretion. In summary, TBT-induced masculinization in gastropods, imposex and intersex, is the clearest example of endocrine disruption described in invertebrates to date that is unequivocally linked to a specific environmental pollutant.

https://setac.onlinelibrary.wiley.com/doi/pdf/10.1002/etc.5620170106

Critical appraisal of the evidence for tributyltin-mediated endocrine disruption in mollusks

The main endocrine-regulated processes of crustaceans have been reviewed in relation to the effects of endocrine-disrupting compounds (EDCs). Molting has been shown to be inhibited by several organic pollutants, such as xenoestrogens and related compounds, as well as by some pesticides. Most of these disrupters are thought to interfere with ecdysone at target tissues, although only for a few has this action been demonstrated in vitro. The heavy metal cadmium appears to inhibit some ecdysone secretion. Juvenoid compounds have also been shown to inhibit molting, likely by interfering with the stimulatory effect of methyl farnesoate. A molt-promoting effect of emamectin benzoate, a pesticide, has also been reported. As for reproduction, a variety of organic compounds, including xenoestrogens, juvenoids and ecdysteroids, has produced abnormal development of male and female secondary sexual characters, as well as alteration of the sex ratio. Cadmium and copper have been shown to interfere with hormones that stimulate reproduction, such as methyl farnesoate, as well as with secretion of the gonad inhibiting hormone, therefore affecting, for example, ovarian growth. Several heavy metals were able to produce hyperglycemia in crustaceans during short times of exposure; while a hypoglycemic response was noted after longer exposures, due to inhibition of secretion of the crustacean hyperglycemic hormone. The ecological relevance of EDCs on crustaceans is discussed, mainly in relation to the identification of useful biomarkers and sentinel species. New experimental approaches are also proposed.

/pdf/endocrine-disruption-in-crustaceans-due-to-pollutants-a-r7dytvcrpp.pdf

Endocrine disruption in crustaceans due to pollutants: a review.

The basic plan of the crustacean endocrine system 1 The endocrine structures 2 X-organ-sinus gland complex 2 Postcommissural organ 3 Pericardial organ 3 Y -o rg a n .... ....... .. ...... ......... ... ......... 3 Androgenic gland 4 O vary 4 Mandibular organ 4 The roles of hormones 5

The endocrine mechanisms of crustaceans

Summary Experiments done in this laboratory showed 5-hydroxytryptamine (5-HT) stimulates gonadal maturation in male and female sand fiddler crabs, Uca pugilator, and red swamp crayfish, Procambarus clarkii. This action of 5-HT is indirect, 5-HT apparently stimulating release of the gonad-stimulating hormone (GSH) that is present in the brain and thoracic ganglia. For example, studies with ovarian explants showed 5-HT has no direct effect on the ovary. But, when ovarian explants were incubated with 5-HT and brain or thoracic ganglia, the incubation medium produced greater ovarian maturation than did the medium when ovarian explants were incubated with brain or thoracic ganglia alone, 5-HT presumably enhancing GSH release. In males 5-HT not only induces testicular maturation but also development of the androgenic glands. 5-HT in males, as in females, apparently triggers GSH release; but in males GSH in turn stimulates the androgenic glands which release the androgenic gland hormone, resulting in testicular ...

Roles of neurotransmitters in regulating reproductive hormone release and gonadal maturation in decapod crustaceans

Effects of Estrogenic Xenobiotics on Molting of the Water Flea,Daphnia magna

From the first discovery of a hormone in a crustacean in the 1920s until the present, the field of crustacean endocrinology has undergone, as do many crustaceans during their development, a marked metamorphosis. The field has moved from the classical era of endocrinological techniques, such as extirpation and additive methods, to the modern era of sophisticated biochemistry and molecular biology. As new investigatory techniques have been devised, crustacean endocrinologists have quickly adopted them and, as a consequence, have made major advances. Nevertheless, there is still much room (and need) for the older techniques, particularly because there is still a vast gap in our knowledge of the endocrine mechanisms of the less highly evolved crustaceans. The bulk of the information we have about crustacean endocrinology has been derived from studies of decapods. Crustacean endocrinology not only provides information about the basic biology of this important group of organisms but also has the potential of greatly enhancing our ability to culture species used as food sources for humans.

Milton Fingerman

Papers

Endocrine disruption in crustaceans due to pollutants: a review.

The endocrine mechanisms of crustaceans

Roles of neurotransmitters in regulating reproductive hormone release and gonadal maturation in decapod crustaceans

Effects of Estrogenic Xenobiotics on Molting of the Water Flea,Daphnia magna

Crustacean endocrinology: a retrospective, prospective, and introspective analysis.