Reduction In Body Burden Research Articles

Feces and molting as microplastic sinks in a mangrove crab

We exposed individuals of the sentinel mangrove crab Minuca rapax to microplastics (MP; 53–63 μm polyethylene spheres) in a long-term experiment (56 days), and assessed MP effects on growth, survival, tissue accumulation, food intake and reduction of body burden through feces and molting. MP exposure did not affect growth and survival. The hepatopancreas accumulated more MP than the gills and muscle. Most of the ingested MP particles were released in the feces and molts, indicating a rapid passage through the digestive tract. MP impaired food intake of M. rapax, with unknown consequences to the local populations. These results provide insights on MP translocation mechanisms, its elimination and toxicity associated with MP.

Embryonic Exposure to Benzotriazole Ultraviolet Stabilizer 327 Alters Behavior of Rainbow Trout Alevin.

Benzotriazole ultraviolet (UV) stabilizers (BUVSs) are used in great quantities during industrial production of a variety of consumer and industrial goods. As a result of leaching and spill, BUVSs are detectable ubiquitously in the environment. As of May 2023, citing concerns related to bioaccumulation, biomagnification, and environmental persistence, (B)UV(S)-328 was recommended to be listed under Annex A of the Stockholm Convention on Persistent Organic Pollutants. However, a phaseout of UV-328 could result in a regrettable substitution because the replacement chemical(s) could cause similar or unpredicted toxicity in vivo, relative to UV-328. Therefore, the influence of UV-327, a potential replacement of UV-328, was investigated with respect to early life development of newly fertilized rainbow trout embryos (Oncorhynchus mykiss), microinjected with environmentally relevant concentrations of UV-327. Developmental parameters (standard length), energy consumption (yolk area), heart function, blue sac disease, mortality, and behavior were investigated. Alevins at 14 days posthatching, exposed to 107 ng UV-327 g-1 egg, presented significant signs of hyperactivity; they moved on average 1.8-fold the distance and at 1.5-fold the velocity of controls. Although a substantial reduction in body burden of UV-327 was observed at hatching, it is postulated that UV-327, due to its lipophilic properties, interfered with neurological development and signaling from the onset of neurogenesis. If these results hold true across multiple taxa and species, a potential contributor to neurodevelopmental disorders might have been identified. These findings suggest that UV-327 poses an unknown hazard to rainbow trout embryos and alevins, rendering UV-327 a potential regrettable substitution to UV-328. However, a qualified statement on a regrettable substitution requires a comparative investigation on the teratogenic effects between the two BUVSs. Environ Toxicol Chem 2024;43:762-771. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Hydrogels and Hydrogel Nanocomposites: Enhancing Healthcare through Human and Environmental Treatment.

Humans are constantly exposed to exogenous chemicals throughout their life, which can lead to a multitude of negative health impacts. Advanced materials can play a key role in preventing or mitigating these impacts through a wide variety of applications. The tunable properties of hydrogels and hydrogel nanocomposites (e.g., swelling behavior, biocompatibility, stimuli responsiveness, functionality, etc.) have deemed them ideal platforms for removal of environmental contaminants, detoxification, and reduction of body burden from exogenous chemical exposures for prevention of disease initiation, and advanced treatment of chronic diseases, including cancer, diabetes, and cardiovascular disease. In this review, three main junctures where the use of hydrogel and hydrogel nanocomposite materials can intervene to positively impact human health are highlighted: 1) preventing exposures to environmental contaminants, 2) prophylactic treatments to prevent chronic disease initiation, and 3) treating chronic diseases after they have developed.

Intake of DDT and its metabolites through food items among reproductive age women in Bangladesh

This study was conducted to make clear the major intake route of DDT in Bangladesh people to develop strategy and policy that could lead to a reduction in body burden especially in the reproductive age women. The concentrations of several POPs (DDT, PCBs, chlordanes, HCHs, HCB, and PeCB) were quantified in food items, human breast milk and house dust collected in Bangladesh in 2011–2012. Among the POPs analyzed in this study, DDT and its metabolites (ΣDDT) showed the highest concentration. The highest median ΣDDT concentration was found in meat (1.3–1100 ng g−1 wet weight) and house dust (30–1100 ng g−1 dry weight), and followed by human breast milk (20–55 ng g−1 wet weight). Estimated daily intake (EDI) was calculated using the DDT concentrations in food items. The highest intake of DDT was found in an infant and 99% of it was via breast milk feeding. DDT intake via consumption of beef accounted for 69% and 72% of that found in children and adults, respectively. The total EDI of DDT did not exceed the tolerable daily intake proposed by the WHO, but the EDI of p,p'-DDT exceeded the oral reference dose proposed by the US Environmental Protection Agency. Further research is required to clarify the reason for the high levels of DDT in beef, which seems to be the major intake route of DDT for women of reproductive age in Bangladesh.

Development and Evaluation of an Intracutaneous Depot Formulation of Corticosteroids Using Transcutol as a Cosolvent: In-vitro, Ex-vivo and In-vivo rat Studies

A topical delivery system has been developed using 50% Transcutol (diethylene glycol monoethyl ether) to decrease the body burden of topically administered dexamethasone and hydrocortisone. The delivery system was evaluated in-vitro using a dissolution apparatus to measure the release of steroid from the gel. In 10 h, 29.6 +/- 0.39% dexamethasone and 45.5 +/- 0.84% hydrocortisone was released from the formulation compared with 23.0 +/- 0.48 and 39.9 +/- 0.77%, respectively, from control formulations without Transcutol. Ex-vivo evaluation was made using rat whole skin in a diffusion cell; the amount of steroid reaching the acceptor cell was significantly less from the formulation containing Transcutol compared with controls. There was also a 2-fold increase in the retention of dexamethasone and a 3-fold increase in the retention of hydrocortisone in the skin at the end of the permeation experiments compared with control experiments. In-vivo studies were made using a formulation containing [3H]hydrocortisone applied to rat skin, followed by measurement of total radioactivity in the blood. For the Transcutol formulation the area under the blood concentration-time curve (0-96 h) was 6.06 +/- 1.27 compared with 2.52 +/- 0.43 x 10(6) d min-1 mL-1 h for the control formulation, indicating a 58% reduction in body burden.

POLYCHLORINATED BIPHENYLS IN BLOOD PLASMA AMONG SWEDISH FEMALE FISH CONSUMERS IN RELATION TO TIME TO PREGNANCY

The purpose of this study was to assess the association between 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) in plasma, a biomarker of exposure to polychlorinated biphenyls (PCB), and time to pregnancy (TTP) in a group of women with a varying dietary exposure to PCB. For 121 Swedish east coast fishermen's wives (median year of birth 1956, range 1945-1968), information on self-reported TTP for the first planned pregnancy (median 2 mo, range 0-48) and CB-153 concentrations from blood samples drawn in 1995 (median 144 ng/g lipid, range 16-566) were available. Each woman's CB-153 concentration in plasma at the time immediately preceding her pregnancy was estimated, taking into account reduction of body burden of CB-153 due to lactation, the yearly reduction of PCB in Baltic Sea fish, as well as the biological half-life of CB153. Based on the estimated CB-153 concentrations, subjects were categorized into tertiles as low (37-206 ng/g lipid), medium (207-330 ng/g lipid), and high (331-1036 ng/g lipid) exposure groups. TTP in the medium- and high-exposure groups were then compared to TTP in the low-exposure group by estimating the corresponding success rate (i.e., the number of pregnancies per person month) ratios (SuRR) using discrete Cox regression, taking into account essential confounders. No obvious association between estimated CB-153 concentration and TTP was observed (medium vs. low: SuRR 0.77 [95% CI 0.47-1.28] and high vs. low: SuRR 0.95 [0.74-1.23]). The present data give no support for a negative association between the plasma CB-153 concentrations observed in the present study and TTP. It should, however, be borne in mind that the study group was rather small and mainly included relatively young women, likely to have been only moderately exposed.

The Dynamics of Metals in the American Oyster, Crassostrea virginica. I. Seasonal Effects

The seasonal dynamics of Mn, Fe, Zn, Cu and Cd were investigated in a genetically similar population of hatchery-reared American oysters, Crassostrea virginica, maintained in plastic trays in the Rhode River, a tributary of the Chesapeake Bay. Samples were collected monthly from September, 1971 through May, 1973. Annual cycles resulting in the turnover of large portions of the body burden were observed for all metals studied. Subtly different patterns of metal dynamics were observed as a result of the reduction in biological variations realized by employing genetically similar oysters. Metals are grouped into two classes according to their dynamics: (1) Mn and Fe concentrations in soft tissues are significantly correlated with shell deposition. A high rate of Mn turnover in soft tissues (approximately 2 times the body burden per day) occurs during the shell growth season. (2) Zn and Cu concentrations are not correlated with shell growth. Zn and Cu body burdens exhibit a gradual increase during the spring and early summer followed by a rapid loss during August–September in which 33% of the Zn and 50% of the Cu is lost in less than 4 weeks. Cd behavior is similar to zn and Cu with a 50% reduction in body burden during an 11 week period between July and October.