Human Health Risk Assessment of Heavy Metal Contamination in New Calabar River.

Concentration and human health risks of heavy metals (Pb, Cu, Cr, Cd, As, Ni) in water, sediment, crab (Tympanotonus fuscatus) and periwinkle (Callinectes amnicola) were assayed in New Calabar River, Nigeria. Results revealed that concentration (mg/L) of the metals in water in the two seasons studied, ranged from 1.1E-2 ± 1.0E-3…for Cd to 2.90 ± 0.03…for Cu. In sediment, the concentration (mg/kg) ranged from 1.1E-2 ± 1.0E-3…for As to 5.17 ± 0.04… for Ni. In biota, the concentration (mg/kg) ranged from 0.01…for As in crab to 19.22…for Cu also in crab. Estimated human health risk from the metals contamination due to consumption of biota gave each of HQ and HI as < 1, indicating no risk except at Agip's sample location where HI was > 1. Estimated human health risk due to dermal absorption through swimming, indicated no risk as each of HQ and HI was < 1. These make the river unpolluted except at Agip's sample location.

Correction: Occurrence and spatial distribution of heavy metals in landfill leachates and impacted freshwater ecosystem: An environmental and human health threat.

[This corrects the article DOI: 10.1371/journal.pone.0263279.].

Prerelease exposure to methyl eugenol increases the mating competitiveness of sterile males of the oriental fruit fly (Diptera: Tephritidae) in a Hawaiian orchard.

Males of the oriental fruit fly, Bactrocera dorsalis (Hendel), are strongly attracted to methyl eugenol (ME), and recent work demonstrated that ingestion of this chemical enhances male mating success, apparently owing its role as a precursor in the synthesis of the male sex pheromone. The current study expanded upon earlier laboratory and field-cage experiments by assessing whether prerelease exposure to ME increased the mating competitiveness of mass-reared, sterile males in Hawaiian orchards. Releases of sterile males from a pupal color-based sexing strain were made weekly in two fruit orchards over 8 mo, with the sterile males at one site given ME for 24 h before release (treated) and the sterile males at the other site given no ME before release (control). Fruits were collected periodically during the study period, and eggs were dissected and incubated to score hatch rate. At both sites, releases of sterile males increased the proportion of unhatched eggs well above prerelease levels, but the incidence of egg sterility was consistently, and statistically, greater in the orchard receiving ME-exposed males. Computed over the entire release period, the average value of Fried's competitive index (that characterizes the mating success of sterile males relative to their wild counterparts) for ME-treated males was 3.5 times greater than that for control males, although this difference was not statistically significant. However, when computed over the period during which egg sterility values were elevated and stable, presumably when females inseminated before the releases were rare or absent, the competitive indices were significantly higher for ME-treated sterile males. The implications of these results for implementing the Sterile Insect Technique against this species are discussed.

Ecological risks of phenolic endocrine disrupting compounds in an urban tropical river.

The distribution of emerging organic contaminants in drinking water sources in Africa is a subject with very scanty data and information. In order to fill knowledge gaps, we report here the distribution and potential ecological risks of three phenolic compounds (bisphenol A (BPA), 4-nonylphenol (NP), and 4-tert-octylphenol (OP)), which have been previously identified to have the potential of endocrine disrupting activity, in surface water and sediment of the New Calabar River. The compounds were quantified using GC-MS. At all sampling sites, a similar concentration pattern of BPA > NP > OP was recorded, with the exception of Choba sampling station in which the levels of these endocrine disrupting compounds were low or undetectable. The levels of BPA in surface water ranged from 1.20 to 63.64 µg/L, whereas those of NP and OP ranged from < 0.20 to 2.15 µg/L and from < 0.10 to 0.68 µg/L, respectively. For sediments, measured levels were from 1.20 to 66.57 µg/kg for BPA, from < 0.35 to 3.37 µg/kg for NP, and from < 0.13 to 0.90 µg/kg for OP. Risk quotients (RQs) assessed for some sensitive organisms (algae, Daphnia magna, and fish) were above 1 for BPA and NP, whereas RQs for OP were below 1. This implies that BPA and NP at the levels detected could have potential risks to the sensitive organisms considered, but low risk for OP.

Continuous fetal heart rate monitoring during late gestation in cattle by means of Doppler ultrasonography: reference values obtained by computer-assisted analysis.

Continuous fetal heart rate (FHR) monitoring using transabdominal Doppler ultrasonography can be assumed to provide information about the viability of the bovine fetus during late gestation, as has been found in humans. To be able to recognize unfavourable fetal conditions, first the normal ranges of FHR parameters in cattle should be established. Therefore, in this study we aimed to determine the normal ranges of computerized FHR parameters, like basal fetal heart rate (BHR), number of accelerations and decelerations per hour and short and long term variation (STV and LTV) during the last 3 weeks before calving (n = 21 cows). Each cow had one recording in each of three episodes of 7 days before parturition. As recording time in the cow is limited, we also studied whether these FHR parameters differ between recordings of 30 and 60 min duration (n = 31 pairs of recordings). The outcomes of FHR recordings with a duration of 30 or 60 min did not differ significantly, except for a higher percentage of signal loss in the 60 min recordings. Therefore, determination of normal ranges was performed in 30 min recordings. BHR decreased from 3 to 2 weeks (114 to 109 bpm; P < 0.0001) before parturition and then remained constant until 2 days before calving. The mean number of accelerations per hour ranged between 4.4 and 5.0 h(-1) and did not change significantly with time. Compared to 3 weeks before parturition, STV was significantly higher at 2 weeks (P < 0.05), but not at 1 week before parturition (8.1, 10.0, and 9.2 ms, respectively). Changes in LTV showed a time course comparable to that of STV, but significance was not reached (51.4, 58.6, and 58.4 ms for respectively 3, 2 and 1 weeks before parturition). No decelerations were found during the period understudy. In conclusion, this study has provided normal ranges of bovine computerized FHR parameters during the last 3 weeks of gestation, allowing a comparison with data from cows with compromised gestations in future.

Ultrasonographic appearance of the conceptus, fetal heart rate and profiles of pregnancy-associated glycoproteins (PAG) and prostaglandin F2alpha-metabolite (PGF2alpha-metabolite) after induction of fetal death with aglepristone during early gestation in cattle.

A higher incidence of fetal losses, especially after the use of artificial reproduction techniques, asks for more intensive monitoring of bovine pregnancies. In this study, a model for fetal death (FD) was created by administering the antiprogesterone aglepristone twice, at Day 47 and 48 of gestation (n=5). Control heifers received the solvent (n=5). The temporal relationships between changes in ultrasonographic appearance of fetal fluids and membranes, fetal heart rate (FHR) and peripheral plasma levels of pregnancy-associated glycoprotein (PAG) and PGF2alpha-metabolite as determined by radioimmunoassay associated with FD were monitored at eight hour intervals around treatment. For the analysis of plasma levels the period under study was divided into five epochs (T1: before injection of aglepristone/solvent; T2: from first to second injection; T3: from second injection to FD; T4: from diagnosis of FD to 56 h later; T5: from 56 h to 104 h after diagnosis of FD). Control heifers produced healthy calves at term, but in treated heifers, FD occurred on average at 58 (range 48-80) h after first injection of aglepristone. Fetal death was always preceded by a visible reduction of the amount of allantoic fluid and by segregation of the allantochorionic membrane from the endometrium. FHR remained rather constant in both groups, but a (non-significant) drop in FHR around 8h before FD was diagnosed in four of five treated animals. All fetuses were expulsed after FD. Levels of PAG remained constant or even slightly increased in controls, but decreased in treated animals from T2 onward: levels during T4 and T5 significantly differed from those during T1 and from values in controls during T4 and T5 (P<0.01). PGF2alpha-metabolite levels did not change in the controls, but in the treated group they were significantly higher during T3 when compared to T1 (P<0.05). After this increase, a sharp decrease in PGF2alpha-metabolite level occurred, reaching a significantly lower level at T5 when compared to control animals (P=0.01). It is concluded, that FD induced by aglepristone is preceded by ultrasonographic visible changes in fetal membranes and fluids and a rise in PGF2alpha-metabolite and is followed by a drop in PAG and PGF2alpha-metabolite.

Prenatal stress and cognitive development and temperament in infants.

Studies in rodents and nonhuman primates indicate that maternal stress during pregnancy can influence the developing fetus, resulting in delay of motor and cognitive development and impaired adaptation to stressful situations. These effects may be mediated by the hypothalamic-pituitary-adrenal (HPA) axis. We examined whether stress during pregnancy predicted developmental outcome of human infants in a prospective design. Self-report data about daily hassles and pregnancy-specific anxiety and salivary cortisol levels were collected in nulliparous pregnant women. Dependent measures were scores on the Bayley Scales of Infant Development and on temperamental questionnaires at 3 and 8 months. Pregnancy-specific anxiety in mid pregnancy predicted lower mental and motor developmental scores at 8 months. Early morning values of cortisol in late pregnancy were negatively related to both mental and motor development at 3 months and motor development at 8 months. Pregnancy-specific anxiety explained 7% of the variance of test-affectivity and goal-directedness at 8 months. Increased maternal stress during pregnancy seems to be one of the determinants of temperamental variation and delay of development of infants and may be a risk factor for developing psychopathology later in life.

Prenatal stress and risk for psychopathology: specific effects or induction of general susceptibility?

This review focuses on prenatal stress as a risk factor for psychopathology. Evidence from animal studies is summarized, and the relevance of prenatal stress models in animals for human studies is discussed. In the offspring of prenatally stressed animals, overactivity and impaired negative feedback regulation of the hypothalamic-pituitary-adrenal axis are consistent findings and may reflect a pathophysiological mechanism involved in the development of psychopathology. Reduced activity of the opioid GABA/benzodiazepine, serotonin, and dopamine systems and increased activity of the sympathico-adrenal system have been found as well. These alterations have been linked to a diverse spectrum of psychopathology. Therefore, the evidence supports the view that exposure to prenatal stress may result in a general susceptibility to psychopathology, rather than exerting a direct effect on a specific form of psychopathology.

Longitudinal study of fetal body movements: nomograms, intrafetal consistency, and relationship with episodes of heart rate patterns a and B.

Our objective was to investigate the longitudinal development of incidence parameters of fetal body movements to define normal reference ranges, to relate them to episodes of fetal heart rate patterns A and B, and to determine the intrafetal consistency for these parameters. Twenty-nine fetuses were studied longitudinally from 24 wk of gestation. Fetal body movements and heart rate were recorded at fortnightly intervals between 24 and 36 wk of gestation and weekly from 36 wk of gestation. Data were analyzed using multilevel analysis. Reference ranges were constructed for the percentage of observation time that movements were present, the number of movement bursts per hour, the mean burst duration, and the median onset-onset interval. The median percentage incidence of fetal body movements decreased from 17% at 24 wk to about 7% near term. The developmental course was the same during active episodes. Body movements also decreased during episodes of relative quiescence, in the course of pregnancy. Intrafetal variance was on average 40-80% of the total range of the four movement parameters. Normal reference ranges were developed for incidence parameters of fetal body movements from 24 wk of gestation onward. The overall decline in the incidence of movements during pregnancy appeared to be a developmental phenomenon and not due to progressively increasing episodes of fetal quiescence. Individual fetuses showed a degree of consistency in the percentage incidence of body movements, but intra- and interfetal variances were generally high, resulting in wide ranges.

Coping in normal pregnancy.

BACKGROUND: In high-risk populations (e.g., adolescents, substance abusers), coping strategies in pregnancy have been studied. Avoidance of the stressful situation and aggressive coping are frequently used and related to postnatal depression and other negative outcomes. Little is known about coping strategies in nulliparous normal-risk pregnancy. OBJECTIVE: To examine the factor structure of the 19-item Utrecht Coping List (UCL-19) in a sample of nulliparous normal-risk pregnant women and to explore the stability, change, and correlates of coping strategies throughout pregnancy. The associations between a particular coping strategy and the reported pregnancy complaints and experienced distress were examined. METHODS: The UCL-19 was filled out and self-report data were collected about neuroticism, locus of control, depression, general anxiety, perceived stress, and physical pregnancy complaints in nulliparous women in early, mid-, and late pregnancy. RESULTS: Confirmatory factor analysis on the UCL-19 revealed 2 coping strategies: emotion-focused coping and problem-focused coping. The factor structure of the UCL-19 had a good stability throughout pregnancy. Some changes in emotion-focused coping and problem-focused coping scores were found, although the absolute differences were rather small. High educational level and low internal locus of control predicted a high score on emotion-focused coping in the early period of pregnancy, F(2, 228) = 11.49, p < .005, R2 = .22. High educational level also predicted a high score on problem-focused coping in early pregnancy, F(1, 229) = 4.80, p < .05, R2 = .06. Emotion-focused coping was negatively and problem-focused coping was positively related to pregnancy complaints (r = -.23, p < .05 and r = .25, p < .005, respectively). Emotion-focused coping in early pregnancy and problem-focused coping in mid-pregnancy were negatively related to experienced distress in early and mid pregnancy, respectively (r = -.27, p < .0005 and r = -.18, p < .01). CONCLUSION: Two coping strategies were consistently found throughout pregnancy: emotion-focused coping and problem-focused coping. Coping in nulliparous normal-risk pregnancy is a process with small temporal variations. Emotion-focused coping was negatively related to the number of reported pregnancy complaints and to experienced distress.