Relative contributions of organochlorine contaminants,parasitism, and predation to reproductive success of eastern spiny softshell turtles (Apalone spiniferus spiniferus) from southern Ontario,Canada

We examined hatching success, predation rates, rates of parasitism, sex ratio, and egg viability in eggs of the eastern spiny softshell (Apalone spiniferus spiniferus), a threatened species in Canada. Eggs were monitored from three populations, located at Thames River, Rondeau Provincial Park, and the Long Point National Wildlife Area, in southern Ontario, Canada in 1998. Concurrently, we measured organochlorine pesticides, PCBs, dibenzo-p-dioxins and furans from eggs from the same nests. Contaminant concentrations in eggs were similar among sites. There was no correlation between hatching success, parasitism and depredation rates, or the proportion of hatchlings that were males with total PCBs or individual pesticides, but there was a positive correlation between egg viability with concentrations in eggs of total PCBs, and with five pesticides. We found no evidence that the reproductive success of softshell turtles was compromised due to organochlorine contamination. The most important factors determining hatching success of eggs was predation, followed by egg viability and parasitism.     

Equilibrium partitioning as the basis for an integrated laboratory and field assessment of the impacts of DDT,DDE and DDD in sediments

Many of the most biologically productive portions of streams are backwater areas which support large populations of benthic macroinvertebrates. The sediments in these locations and their associated macroinvertebrate communities are frequently subjected to chemical inputs and physical perturbations. Historically, assessment of the effects of contaminants in sediments have emphasized chemical analyses and either laboratory toxicity tests or in-stream monitoring of benthic macroinvertebrate community structure. However, combining the chemical and biological approaches provides a more powerful assessment technique. Such an integrated approach, combining laboratory water-only and sediment toxicity tests with Hyalella azteca and Chironomus tentans, field surveys of benthic macroinvertebrate community structure and evaluation of chemical data using equilibrium partitioning theory was used to assess the effects of DDT, DDE and DDD (collectively termed DDTR) in the sediments of the Huntsville Spring Branch-- Indian Creek (HSB--IC) stream system in the southeastern USA. Benthic macroinvertebrate populations in the HSB--IC system still appear to be adversely affected by DDTR residues within the sediments even though DDT discharges to the stream were stopped over 20 years ago and a major remediation project was completed in the late 1980s. This conclusion is based on a weight of evidence approach which incorporates (1) the observed sediment toxicity to C. tentans and H. azteca in laboratory tests, (2) the identification of DDTR as the likely cause of effects observed during laboratory toxicity tests, (3) the absence of appropriate sensitive species from groups such as the Ephemeroptera, Plecoptera, Trichoptera and Amphipoda, (4) the presence of reduced numbers of both total individuals and species of chironomids and oligochaetes relative to nearby streams not contaminated by DDTR and (5) the observed distribution of benthic macroinvertebrates in relation to organic carbon-normalized concentrations of DDTR and equilibrium partitioning-based predicted sediment toxic units of DDTR     

Effects of DDT (Chlorophenotane) Administration on Glucose Uptake and Brush Border Enzymes in Monkey Intestine

Abstract A considerable increase occurs in D-glucose uptake and brush border sucrase and lactase activities in the intestine of monkeys treated with a single oral dose of DDT. Brush border alkaline phosphatase activity remains unaffected in the pesticide treated animals. In vitro addition of DDT has no effect on the sugar absorption and disaccharidase activities.     

The insecticide 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT) alters the membrane raft location of the TSH receptor stably expressed in Chinese hamster ovary cells

DDT is a highly lipophilic molecule known to deplete membrane rafts of their phosphoglycolipid and cholesterol contents. However, we have recently shown that DDT can also alter the thyroid homeostasis by inhibiting TSH receptor (TSHr) internalization. The present study was undertaken to verify whether DDT goitrogenic effects are due to the insecticide acting directly on TSHr or via alteration of the membrane rafts hosting the receptor itself. Our results demonstrate that, in CHO-TSHr transfected cells, TSHr is activated in the presence of TSH, while it is inhibited following DDT exposure. DDT can also reduce the endocytic vesicular traffic, alter the extension of multi-branched microvilli along their plasma membranes and induce TSHr shedding in vesicular forms. To verify whether TSHr displacement might depend on DDT altering the raft constitution of CHO-TSHr cell membranes the extent of TSHr and lipid raft co-localization was examined by confocal microscopy. Evidence shows that receptor/raft co-localization increased significantly upon exposure to TSH, while receptors and lipid rafts become dislodged on opposite cell poles in DDT-exposed CHO-TSHr cells. As a control, under similar culturing conditions, diphenylethylene, which is known to be a lipophilic substance that is structurally related to DDT, did not affect the extent of TSHr and lipid raft co-localization in CHO-TSHr cells treated with TSH. These findings corroborate and extend our view that, in CHO cells, the DDT disrupting action on TSHr is primarily due to the insecticide acting on membranes to deplete their raft cholesterol content, and that the resulting inhibition on TSHr internalization is due to receptor dislodgement from altered raft microdomains of the plasma membrane.     

Histopathological changes in the reproductive system (ovaries and testes) of Oreochromis mossambicus following exposure to DDT

This study assesses the effects of 1,1-bis (4-chlorophenyl)-2,2,2-trichloroethane (DDT) on the reproduction and gonadal histology of adult Mozambique tipalia (Oreochromis mossambicus). The fish were allowed to breed, following exposure to 2 and 5μg/l of waterborne technical-grade DDT for 40 days. Fertilized eggs were artificially incubated. In the 5μg/l exposure, posthatch survival was significantly lower, and prevalence of larval skeletal deformities significantly higher, compared to the control (p<0.05). Incomplete axial development was the common gross deformity in posthatch larvae, caused by failure to develop chondroblasts posterior to the buccopharyngeal cavity. There were no significant differences in the gonadosomatic index of exposed and non-exposed male and female adults. The exposure caused increased oocyte atresia in the ovaries and disorganization of seminiferous lobules in the testes of adults. DDT exposure reduced survival and increased deformities in larvae, at levels that did not cause severe histopathological changes to parental gonads.     

Association of serum levels of p,p’- Dichlorodiphenyldichloroethylene (DDE) with type 2 diabetes in African American and Caucasian adult men from agricultural (Delta) and non-agricultural (non-Delta) regions of Mississippi

Epidemiological associations were reported in several studies between persistent organochlorine organic pollutants and type 2 diabetes mellitus (T2D). Mississippi is a highly agricultural state in the USA, particularly the Delta region, with previous high usage of organochlorine (OC) insecticides such as p,p’- dichlorodiphenyltrichloroethane (DDT). In addition, there is a high proportion of African Americans who display elevated prevalence of T2D. Therefore, this State provides an important dataset for further investigating any relationship between OC compounds and metabolic diseases. The aim of this study was to assess whether soil and serum levels of OC compounds, such as p,p’- dichlorodiphenyldichloroethylene (DDE), arising from the heavy historical use of legacy OC insecticides, might serve as an environmental public health indicator for T2D occurrence. Soil samples from 60 Delta and 60 non-Delta sites randomly selected were analyzed for the presence of OC compounds. A retrospective cohort study of adult men (150 from each region) was recruited to provide a blood sample for OC compound quantitation and select demographic and clinical information including T2D. Using multivariable logistic regression, an association was found between increasing serum DDE levels and T2D occurrence in non-Delta participants (those subjects with lower serum DDE levels), as opposed to Delta participants (individuals with higher serum DDE levels). Thus, while there was a relationship between serum DDE levels and T2D in those with lower burdens of DDE, the lack of association in those with higher levels of DDE indicates a complex non-monotonic correlation between serum DDE levels and T2D occurrence complicating the goal of finding a public health marker for T2D.

Abbreviations: BMI, body mass index; CVD, cardiovascular disease; CDC, Center for Disease Control, United States of America; DDE, p,p’- dichlorodiphenyldichloroethylene; DDT, p,p’- dichlorodiphenyltrichloroethane; GC/MS, gas chromatography/mass spectrometry; GIS, geographic information system; GPS, global positioning system; HDL, high-density lipoprotein; HTN, hypertension; IDW, inverse distance weighting; IRB, Institutional Review Board; LDL, low-density lipoprotein; LOQ, limit of quantitation; NHANES, National Health and Nutrition Examination Surveys; POPs, persistent organic pollutants; OC, organochlorine; PCB, polychlorinated biphenyl; SIM, single-ion monitoring; T2D, type 2 diabetes mellitus; USA, United States of America.     

An evaluation of the effects of persistent environmental contaminants on the reproductive success of Great Blue Herons (Ardea herodias) in Indiana

Contaminants in Great Blue Herons (Ardea herodias) from Indiana were quantified to determine if levels were high enough to impair reproduction. During 2005 and 2006, 35 eggs were collected from 6 colonies and analyzed for contaminants. Between 30 and 101 nests were monitored in 7 colonies weekly over a 3-month period to determine reproductive and fledging success. Average levels (±SD) of polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and organochlorine pesticides in egg yolks were 3,101 (±4,737), 7.20 (±2.96), and 2,869 (±2,291) ppb, respectively. Reproductive success (average number of chicks fledged per active nest) and fledging success (number of chicks fledged per successful nest) averaged 1.52 and 1.92 chicks, respectively. Contaminant levels measured in eggs from this region are comparable to those observed not having affects on reproductive success elsewhere; therefore, factors other than environmental contamination may be affecting reproductive success of Great Blue Herons in study colonies.     

The influence of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and its metabolite—dichlorodiphenyldichloroethylene (DDE) on mRNA expression for NP-I/OT and PGA, involved in oxytocin synthesis in bovine granulosa and luteal cells

The effect of polychlorinated biphenyls (PCBs) congeners (PCB 77, PCB 126, PCB 153) and their technical mixture—Aroclor (Ar) 1248, as well as dichlorodiphenyltrichloroethane (DDT) and its metabolite—dichlorodiphenyldichloroethylene (DDE; two individual isomers p,p′- and o,p′- or their mixture, 95% and 5%, respectively) at the dose of 10 ng/ml each, on the gene expression of (a) oxytocin (OT) precursor—neurophysin–oxytocin (NP-I/OT) and (b) peptidyl glycine-α-amidating mono-oxygenase (PGA), the terminal enzyme in the pathway of OT synthesis, was studied. Granulosa cells from follicles >1 cm in diameter, collected on days 19–21 of estrous cycle, and luteal cells from corpora lutea (CL) collected on days 8–12 of the estrous cycle were used. The cells were incubated (6 h) with these xenobiotics and the expression of NP-I/OT and PGA genes was determined. All PCBs increased (P < 0.05) NP-I/OT gene expression in granulosa cells. Similarly, all PCBs but PCB 126 increased (P < 0.05) PGA gene expression in these cells. DDT and DDE increased (P < 0.05) gene expression of NP-I/OT in granulosa cells, while gene expression of PGA in these cells was stimulated (P < 0.05) by DDE only. The mRNA expression for NP-I/OT and PGA in luteal cells was increased (P < 0.05) by PCB 77 and PCB 153. Both DDE isomers and mixture also stimulated (P < 0.05) of NP-I/OT mRNA expression, while increase (P < 0.05) of PGA mRNA expression was elicited by incubation of these cells with DDE mixture and Ar 1248.Obtained data suggest that PCBs, DDT and DDE can affect the mRNA expression for NP-I/OT and PGA in bovine granulosa and luteal cells.     

Metabolomics in the assessment of chemical‐induced reproductive and developmental outcomes using non‐invasive biological fluids: application to the study of butylbenzyl phthalate

This study was conducted to evaluate the use of metabolomics for improving our ability to draw correlations between early life exposures and reproductive and/or developmental outcomes. Pregnant CD rats were exposed by gavage daily during gestation to vehicle or to butylbenzyl phthalate (BBP) in vehicle at a level known to induce effects in the offspring and at a level previously not shown to induce effects. Urine was collected for 24 h (on dry ice using all glass metabolism chambers) from dams on gestational day 18 (during exposure) and on post natal day (pnd) 21, and from pnd 25 pups. Traditional phenotypic anchors were measured in pups (between pnd 0 and pnd 26). Metabolomics of urine collected from dams exposed to vehicle or BBP exhibited different patterns for endogenous metabolites. Even three weeks after gestational exposure, metabolic profiles of endogenous compounds in urine could differentiate dams that received the vehicle, low dose or high dose of BBP. Metabolic profiles could differentiate male from female pups, pups born to dams receiving the vehicle, low or high BBP dose, and pups with observable adverse reproductive effects from pups with no observed effects. Metabolites significant to the separation of dose groups and their relationship with effects measured in the study were mapped to biochemical pathways for determining mechanistic relevance. The application of metabolomics to understanding the mechanistic link between low levels of environmental exposure and disease/dysfunction holds huge promise, because this technology is ideal for the analysis of biological fluids in human populations. Copyright © 2009 John Wiley & Sons, Ltd.     

Identification and assessment of the effects of chemicals on reproduction and development (reproductive toxicology)

Most studies for determining the reproductive toxicity of a chemical have to be conducted with whole animals. Test procedures used to investigate parts or the whole of the reproductive cycle are described in current guidelines. Other techniques, such as in vitro methods, and those for investigating specific events in the cycle, are under development. Epidemiological studies can give valuable information, although they are difficult to perform and interpret in practice. There is a need for more epidemiological studies of exposed populations and for recording and quantifying the concentrations of chemicals to which such populations are exposed. It is suggested that animal experiments should be programmed in a stepwise manner, and should take into account effects seen in previous toxicity studies. The programme of tests for determining reproductive toxic potential should be established on a case-by-case basis, since many factors will influence the choice of studies and the sequence in which they should be performed.     

Depression in the barrio: An analysis of the risk and protective nature of cultural values among Mexican American substance users

Understanding the effect of cultural values on depression and how social networks influence these relationships may be important in the treatment of substance-using, Mexican American populations. Latino cultural values, familismo, personalismo, fatalismo, and machismo, may be associated with depression among Latinos. The current study identified the association of traditional Latino values on depressive symptomatology among a sample of Mexican American heroin injectors. A cross-sectional research design and field-intensive outreach methodology were utilized to recruit 227 Mexican American men. Participants were categorized into depressed and nondepressed groups. Relations among cultural values and depression were examined using logistic regression. Findings indicate that drug-using men with higher familismo and fatalismo scores are protected against depressive symptomatology. Relations between familismo and depression seem to be moderated by having a drug use network. In addition, findings reveal that age is inversely related to depressive symptomatology. Young Mexican American heroin users who do not ascribe to traditional Latino values may be highly associated with depression and therefore more vulnerable to riskier drug use behaviors. Moreover, drug-using social networks may affect the protective nature of certain cultural values. Further research is needed to identify whether culturally tailored treatments can cultivate these values while simultaneously undermining the effect of substance-using social networks in order to reduce depression symptoms among this group of high-risk substance users.     

Monitoring and risk assessment of pesticides in fresh omija (Schizandra chinensis Baillon) fruit and juice

Schizandra chinensis Baillon, or omija, is a fruit native to northeast Asia that is cultivated in South Korea and China. Fresh omija fruit has been used in beverages, traditional East Asian medicine and cosmetics because of its complex flavor and pharmacological effectiveness. The objective of this study was to analyze residue levels of 33 kinds of pesticides on fresh omija fruits and in omija juices produced in South Korea. A risk assessment of the pesticides in omija juice was conducted by calculating EDI and ADI. Most of the pesticide levels were below the LOD in fresh omija fruits. Among the detected compounds, the most frequently detected pesticide was ethoprophos. The EDIs of ethoprophos, pendimethalin and hexaconazole were 5.89E-03, 7.08E-04 and 4.73E-05, respectively. The percent of EDI to ADI of ethoprophos, pendimethalin and hexaconazole was 28.0%, 13.6% and 4.5%, respectively. The results of this research concluded that the detected pesticides are not harmful to human beings.     

Exposure to monocrotophos pesticide during sexual development causes the feminization/demasculinization of the reproductive traits and a reduction in the reproductive success of male guppies (Poecilia reticulata)

Monocrotophos is a highly toxic organophosphorus pesticide that has been confirmed to be an endocrine‐disrupting chemical. To evaluate the influence of this pollutant on the reproductive system of male fish, we studied the sex steroid levels, reproductive traits, sex ratio, and reproductive success in male guppies (Poecilia reticulata) exposed to 40% monocrotophos pesticide at the nominal concentrations of 0.01, 0.10, and 1.00 mg/L for 90 days from birth to adulthood in a semi‐static exposure system. Radioimmunoassay and western blot analyses demonstrated that the long‐term exposure to monocrotophos pesticide during the sexual development of male guppies caused a significant increase in 17β‐estradiol levels and consequently induced vitellogenin synthesis, suggesting the feminization of the males. Monocrotophos pesticide also caused a significant decrease in testosterone levels, which consequently inhibited testis growth and reduced the sperm count and the area and intensity of their sexually attractive orange spots, which collectively indicated the significant demasculinization of the male sexual characteristics. Furthermore, these changes in the sexual characteristics at the cellular and organ levels translated into ecologically important effects on the reproductive success at the individual level, as measured by a decrease in offspring production and survival rate. The present study provides the first evidence that monocrotophos pesticide can cause severe reproductive abnormalities in fish due to its endocrine‐disrupting action.     

An analysis of the results from Two-Generation Reproduction Toxicity Studies to assess the value of mating animals of the second (F1) generation for the detection of adverse treatment-related effects on reproductive performance

The need to routinely perform a two-generation study to assess reproductive performance is under debate. This review has analysed the results from 22 consecutive Two-Generation Reproduction Toxicity Studies performed within our laboratories, to determine the value of mating each generation in the detection of treatment-related effects on reproductive performance. The chemicals included 13 agrochemicals, 5 industrial chemicals and 4 food additives. Four chemicals (all from the agrochemical group) were found to have clear treatment-related effects and in three studies effects were confined to the second (F1) generation. For the three studies with second (F1) generation effects, we applied the triggers, proposed by the Agricultural Chemical Safety Assessment (ASCA) Technical Committee of HESI, for extension of the one-generation study and found that mating of the second (F1) generation would have been triggered in these studies by effects on the F1 offspring growth and sexual maturation. No effects were seen in the original parental (F0) generation which would have activated the change from a one- to a two-generation study.     

An Assessment of PCBs and OC Pesticides in Eggs of Double-crested (<Emphasis Type="Italic">Phalacrocorax auritus</Emphasis>) and Pelagic (<Emphasis Type="Italic">P. pelagicus</Emphasis>) Cormorants from the West Coast of Canada, 1970 to 2002

Eggs of double-crested and pelagic cormorants were collected between 1970 and 2002 from colonies in the Strait of Georgia, BC, Canada, and assayed for concentrations of organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs). Double-crested cormorant eggs from the early 1970’s contained up to 4.1 mg kg⁻¹ p,p′-DDE and 12.5 mg kg⁻¹ ∑PCBs. Corresponding values for pelagic cormorant eggs were 1.5 mg kg⁻¹ p,p′-DDE and 3.9 mg kg⁻¹ ∑PCBs. Egg tissue concentrations of the dominant OC pesticides and ∑PCBs dropped mainly during the 1970’s, with minor declines thereafter. The data suggest that contaminant levels in cormorants have now stabilized at low levels throughout the resident population. Small but significant latitudinal gradients in several OC pesticides and PCBs indicated that areas of the southern strait were more contaminated than areas of the less populated northern strait. Interspecific differences in contamination may indicate that pelagic cormorants have a reduced capacity to metabolize chlordanes, DDT and PCBs compared to double-crested cormorants. Alternatively, the two species may have more divergent prey bases than previously thought. During the 1980’s, TCDD toxic equivalents, largely contributed by polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), were correlated with physiological and biochemical alterations. Also, from 1989 to 1990, four deformed cormorant chicks (two of each species) were found during nest visits; none were found between 1991 and 1995. The relative rates of deformed chicks were 6 per 10,000 for double-crested and 16 per 10,000 for pelagic cormorants. The findings of deformed chicks were coincident with the period of highest PCDD and PCDF contamination; however, the sample sizes were too low to derive a substantive connection. Colony-wide productivity of double-crested cormorants was poorer in the southern colonies where PCBs in particular were elevated. While of concern, these lines of evidence are insufficient to conclude that chlorinated hydrocarbon contamination was a dominant contributor to population declines. It seems more probable that ecological variables, particularly changing prey and predator dynamics, drove the reductions in population size.     

Guidance on classification for reproductive toxicity under the globally harmonized system of classification and labelling of chemicals (GHS)

Abstract

The Globally Harmonised System of Classification (GHS) is a framework within which the intrinsic hazards of substances may be determined and communicated. It is not a legislative instrument per se, but is enacted into national legislation with the appropriate legislative instruments. GHS covers many aspects of effects upon health and the environment, including adverse effects upon sexual function and fertility or on development. Classification for these effects is based upon observations in humans or from properly designed experiments in animals, although only the latter is covered herein. The decision to classify a substance based upon experimental data, and the category of classification ascribed, is determined by the level of evidence that is available for an adverse effect on sexual function and fertility or on development that does not arise as a secondary non-specific consequence of other toxic effect. This document offers guidance on the determination of level of concern as a measure of adversity, and the level of evidence to ascribe classification based on data from tests in laboratory animals.     

Assessment of in vitro antiovulatory activities of nonsteroidal anti‐inflammatory drugs and comparison with in vivo reproductive toxicities of medaka (Oryzias latipes)

Nonsteroidal anti‐inflammatory drugs (NSAIDs) are widely used therapeutic agents; however, their pharmacological actions raise concerns about potential risks to the reproductive health of aquatic vertebrates. In the present study, a medaka ovulation assay was applied as an in vitro model to evaluate NSAID‐induced antiovulatory activity. We first tested five NSAIDs, including diclofenac sodium (DCF), ketoprofen (KP), salicylic acid (SA), mefenamic acid (MA), and acetylsalicylic acid (ASA) for their antiovulatory activities toward the follicles isolated from the ovaries of spawning females. Of all the chemicals tested, DCF had the highest antiovulatory activity, with the concentration that caused 50% inhibition (IC50) (101 µM). MA was the second most potent inhibitor following DCF, but KP, SA, or ASA had little inhibitory effect on the ovulation of the follicles. The in vitro antiovulatory activity of five NSAIDs showed good correlation with data published on the inhibitory activity on human COX‐2. Second, we selected DCF and SA as the most and least potent NSAIDs, respectively, and examined the effects on reproduction of intact fish in order to evaluate whether the ovulation assay was a reasonable predictor of potential reproductive effects in fish. Females exposed to DCF showed a concentration‐dependent decrease in the number of spawned eggs and an increment in the gonadosomatic index (GSI), possibly due to an anovulation in the females. In contrast, neither fecundity nor the GSI of females decreased at up to 20 mg/L of SA, at which acute lethality to medaka was induced. In conclusion, the medaka ovulation assay reflected the potency of NSAID‐induced antiovulatory activity and may thus serve as an in vitro model for the prediction of NSAID‐induced reproductive toxicity. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1710–1719, 2016.     

Evaluation of reproductive/developmental and repeated dose (subchronic) toxicity and cytogenetic effects in rats of a roofing asphalt fume condensate by nose-only inhalation

A Type III Built-up Roofing Asphalt (BURA) fume condensate was evaluated for subchronic systemic toxicity and reproductive/developmental toxicity screening in Wistar rats, by OECD protocol 422 and OECD cytogenetic protocol 474. Animals were exposed by nose-only inhalation to target concentrations of 30, 100 and 300 mg/m3 total hydrocarbons (actual concentrations, 30.0, 100.1 and 297.3 mg/m3). The study was performed to assess potential hazards from asphalt fumes to which humans could be exposed during application. No adverse effects were seen for spermology, reproductive or developmental parameters or early postnatal development of offspring from day 1 to 4 postpartum. BURA fume condensate did not induce any significant increases in micronucleus frequency in polychromatic erythrocytes of rat bone marrow nor was neurobehavioral toxicity observed at any dose. Systemic effects were slight and seen at doses above those measured at work sites. The systemic NOAEC of 100 mg/m3 for males was based on decreased body weight gain, food consumption and increased absolute and relative lung wet weight correlated with slight histological changes in the lung, primarily adaptive in nature at 300 mg/m3. The female NOAEC of 30 mg/m3 was based on a statistically significant increase in relative wet lung weight at higher doses, correlated with slight histopathologic effects in the lungs at the highest dose. However, no increase in relative lung weight was seen in breeding females at 100 mg/m3.