Evaluation of Paralytic Shellfish Toxins in Marine Oyster Farming and Microalgae in the Atlantic Amazon Evidences Safety but Highlights Potential Risks of Shellfish Poisoning.

Marine phycotoxins are organic compounds synthesized by some species of microalgae, which accumulate in the tissues of filter-feeder organisms such as bivalve mollusks. These toxins can cause acute intoxication episodes in humans, a severe threat to aquaculture and fisheries. In the State of Pará, Brazil, oyster farming has community, artisanal and sustainable bases, using mangroves as cultivation environment and seed banks. In small-scale production, there are often no established methods of safeguarding the health of consumers elevating the potential risks of shellfish poisoning outbreaks. Our study evaluated the presence of phycotoxins in oysters cultivated in five municipalities in the region of the Atlantic Amazon (Pará, Brazil) assessing the quality of the final product. We further evaluated the microalgae, water quality, and the spatio-temporal variation of physicochemical factors in the same area. Diatoms dominated the microalgae composition, followed by dinoflagellates, some of which are reported to be potentially toxic and producers of paralytic shellfish toxins. For the first time, we describe the occurrence of the potentially toxic dinoflagellate Ostreopsis sp. in the Amazon region. Furthermore, for the first time, toxins were detected in oyster farming in the northeast of the State of Pará, namely GTX2,3, STX, and dc-STX nevertheless, with nontoxic values. The identified toxins represent a potential threat to shellfish consumers.

Health Risk Assessment Attributed to Consumption of Fish Contaminated with Mercury in the Rio Branco Basin, Roraima, Amazon, Brazil.

The aim of this study was to assess the health risk attributable to the consumption of mercury-contaminated fish for the urban and non-urban populations living in the Roraima state, Amazon, Brazil. Seventy-five fish specimens distributed across twenty different species, comprising four trophic levels (i.e., herbivore, omnivore, detritivore, and carnivore), were collected at four locations in the Branco River Basin. The fish samples were sent to the Toxicology Laboratory at Evandro Chagas Institute to determine the total-Hg levels by using the cold vapor atomic system (CVAAS). The total-Hg levels ranged from 0 to 3.159 µg/g. The average concentration in non-carnivorous species (n = 32) was 0.116 µg/g, and among carnivorous fish (n = 43), it was 0.869 µg/g. The weighted average of contamination levels for all samples was 0.545 µg/g. The health risk assessment was conducted according to the methodology proposed by the World Health Organization and different scenarios of human exposure were considered, based on three levels of fish consumption (low: 50 g/day; moderate: 100 g/day and high: 200 g/day). Women of childbearing age ingest 5 to 21 times more mercury than the dose considered safe by the U.S. EPA and intake a dose from 2 to 9 times higher than the safe dose proposed by FAO/WHO. Children under 5 years of age ingest from 18 to 75 times the dose proposed by the U.S. EPA and from 8 to 32 more mercury than the limit proposed by FAO/WHO. In summary, regardless of the level of fish consumption, type of residency (urban or non-urban), and the subset of the population analyzed, anyone who consumes fish from the locations sampled is at high risk attributable to mercury ingestion, with the only exception of adult men, who consume an average of 50 g of fish per day.

High Genetic Diversity and Antimicrobial Resistance in Escherichia coli Highlight Arapaima gigas (Pisces: Arapaimidae) as a Reservoir of Quinolone-Resistant Strains in Brazilian Amazon Rivers.

The increasing prevalence of multi-drug resistant (MDR) Escherichia coli in distinct ecological niches, comprising water sources and food-producing animals, such as fish species, has been widely reported. In the present study, quinolone-resistant E. coli isolates from Arapirama gigas, a major fish species in the Brazilian Amazon rivers and fish farms, were characterized regarding their antimicrobial susceptibility, virulence, and genetic diversity. A total of forty (40) specimens of A. gigas, including 20 farmed and 20 wild fish, were included. Thirty-four quinolone-resistant E. coli isolates were phenotypically tested by broth microdilution, while resistance and virulence genes were detected by PCR. Molecular epidemiology and genetic relatedness were analyzed by MLST and PFGE typing. The majority of isolates were classified as MDR and detected harboring blaCTX-M, qnrA and qnrB genes. Enterotoxigenic E. coli pathotype (ETEC) isolates were presented in low prevalence among farmed animals. MLST and PFGE genotyping revealed a wide genetic background, including the detection of internationally spread clones. The obtained data point out A. gigas as a reservoir in Brazilian Amazon aquatic ecosystems and warns of the interference of AMR strains in wildlife and environmental matrices.

An Assessment of Health Outcomes and Methylmercury Exposure in Munduruku Indigenous Women of Childbearing Age and Their Children under 2 Years Old.

In line with the 1000-day initiative and the Sustainable Development Goals (SDG) 2 and 3, we present a cross-sectional analysis of maternal health, infant nutrition, and methylmercury exposure within hard-to-reach indigenous communities in the state of Pará, Brazilian Amazon. We collected data from all women of childbearing age (i.e., 12-49) and their infants under two years old in three Munduruku communities (Sawré Muybu, Sawré Aboy, and Poxo Muybu) along the Tapajos River. We explored health outcomes through interviews, vaccine coverage and clinical assessment, and determined baseline hair methylmercury (H-Hg) levels. Hemoglobin, infant growth (Anthropometric Z scores) and neurodevelopment tests results were collected. We found that 62% of women of childbearing age exceeded the reference limit of 6.0 µg/g H-Hg (median = 7.115, IQR = 4.678), with the worst affected community (Sawré Aboy) registering an average H-Hg concentration of 12.67 µg/g. Half of infants aged under 24 months presented with anemia. Three of 16 (18.8%) infants presented H-Hg levels above 6.0 µg/g (median: 3.88; IQR = 3.05). Four of the 16 infants were found to be stunted and 38% of women overweight, evidencing possible nutritional transition. No infant presented with appropriate vaccination coverage for their age. These communities presented with an estimated Infant Mortality Rate (IMR) of 86.7/1000 live births. The highest H-Hg level (19.6 µg/g) was recorded in an 11-month-old girl who was found to have gross motor delay and anemia. This already vulnerable indigenous Munduruku community presents with undernutrition and a high prevalence of chronic methylmercury exposure in women of childbearing age. This dual public health crisis in the context of wider health inequalities has the potential to compromise the development, health and survival of the developing fetus and infant in the first two critical years of life. We encourage culturally sensitive intervention and further research to focus efforts.

Application of the Quartz Crystal Microbalance Method for Measuring Mercury in the Air of Working Environments Involved to Artisanal and Small-scale Gold Mining (ASGM).

Artisanal small gold mining (ASGM) is responsible for approximately 40% of the total Hg emissions into the atmosphere worldwide. In developing countries, many people are engaged in ASGM activities. We developed a small, simple Hg measuring device, which detects Hg in the air based on the change of the oscillation frequency of an Au electrode on a quartz crystal microbalance (QCM). This device is called QCM-Hg. We tested the viability of the QCM-Hg in various work settings including a gold mining area and gold shops. In working environments with an airborne Hg concentration of several µg m-3, the changing rate of the oscillation frequency for either 2 or 3 min corresponded with the Hg concentrations measured using the conventional method of gold amalgamation and cold vapor atomic absorption spectrometer (CVAAS). The results revealed that the QCM-Hg is a useful device for real-time Hg monitoring in actual working environments related to ASGM activities and Hg treatment facilities.

Maternal and embryonic trace element concentrations and stable isotope fractionation in the smalleye smooth-hound (Mustelus higmani).

Here, we evaluate maternal offloading of 16 trace elements (Essential: Co, Cr, Cu, Fe, Mn, Ni, Se and Zn; Nonessential: Al, As, Ba, Cd, Hg, Pb, Tl and U) and determine mother-offspring isotopic fractionation of δ13C and δ15N in muscle and liver tissue of four pregnant Mustelus higmani and 18 associated embryos sampled from the Amazon Coast of Brazil. Embryo muscle tissue had significantly higher concentrations of most trace elements when compared to mothers, with the exception of Hg. Embryo liver accumulated more nonessential elements than muscle (n = 7 vs. 0, respectively), while the Se:Hg molar ratio was >1 in liver and muscle of both mothers and embryos. Livers of embryos were moderately enriched in δ13C and δ15N when compared to that of their mother. Negative correlations were observed between embryo body length and δ13C and trace elements concentrations. We conclude that mothers offload a large portion of all essential elements and Al, As and Pb to their young and that the isotopic fractionation of embryos reflects maternal diet and habitat occupied, with δ13C diluted with embryonic growth. We also show that muscle and liver accumulate trace elements at different rates relative to the body length of embryos. The Se:Hg molar ratio suggests that Se could play a protective role against Hg toxicity during early stages of M. higmani embryonic development.

Mercury in fish marketed in the Amazon Triple Frontier and Health Risk Assessment.

Fish has great socioeconomic, cultural, and nutritional importance for Amazonian populations. Despite all health benefits, fish can accumulate great amounts of mercury (Hg). The entry of Hg in aquatic trophic chains is an issue of concern to animal and human health. Higher risks of human exposure are strongly related to fish consumption. Upper Solimões population has one of the highest fish consumption rates of the Amazon. This study aimed to access the concentration of total Hg (THg) in muscle, liver, and gills of 17 species of fishes marketed in the Upper Solimões Region and Health Risk Assessment. Higher concentrations were observed in Carnivores/Piscivores. The highest THg concentration was found in liver of Cichla ocellaris (4.549 µg/g) and the lowest in gills of Hoplosternum littorale (0.002 µg/g). Most species had higher THg concentrations in muscle>liver>gills, in the Ebb period, and liver>muscle>gills, in the Flood period. Hoplias malabaricus, Pseudoplatystoma fasciatum, Plagioscion squamosissimus, Ageneiosus inermis, and C. ocellaris presented average THg concentrations above the safe limit stablished by WHO. THg levels in C. ocellaris, H. malabaricus, P. squamosissimus, P. fasciatum, and Semaprochilodus insignis were higher than those found in fish of heavily impacted areas. Signs of bioaccumulation and biomagnifications of Hg can already be observed in this region. The Western Amazon Region urgently needs government actions to inhibit Hg release in aquatic ecosystems and to advise this population on the safe amount of fish to be eaten according to species and period of the year.

A comparative study of cadmium levels in blood from exposed populations in an industrial area of the Amazon, Brazil.

Chemical pollution from industrial sources is one of the main problems affecting the environment. In urban areas, the emission of toxic gases and particulates to the atmosphere can damage human health. Cadmium (Cd) is one of the most ecotoxic metals among these pollutants, even at low concentrations. In this study, environmental exposure to Cd was evaluated from the Cd blood levels (CdB) of the human populations living in two Amazonian districts. The first was Bairro Industrial (BIN), which is located next to the industrial complex in Barcarena City, while the second was Vila do Beja (VBJ), a control group located in the farthest area from industrial activities in Abaetetuba City. Sectional and comparative studies were applied for both districts. Sampling (N = 469) occurred in 2012 and 2013. Gender, age, residence time, drinking water source, alcohol consumption, and smoking were used as independent variables. CdB levels were analyzed by induced coupled plasma mass spectrometry (ICP-MS). In BIN, geometric mean and median CdB levels were 0.27 and 0.43 µg∙L-1, respectively (range: ≤0.03-17.49 µg∙L-1), while in VBJ these were 0.19 and 0.23 µg∙L-1 (range: ≤0.03-2.38 µg∙L-1). The higher CdB concentration in the blood of people from BIN was similar to levels previously found in people living near other industrial areas, and showed that the BIN residents were more exposed to Cd pollution. The studies showed the need for surveillance actions to evaluate possible routes of exposure, avoiding the future worsening of the health of the population living next to industrial areas in the Amazon.

Levels of organochlorine pesticides in Amazon turtle (Podocnemis unifilis) in the Xingu River, Brazil.

Due to the toxicity and high environmental persistence of organochlorine pesticides in aquatic organisms, turtles have been studied as environment biomonitors. These animals are important sources of protein for the riverside and indigenous peoples of the Brazilian amazon. In the present study, organochlorine pesticide contamination was investigated in Podocnemis unifilis. Liver, muscle and fatty tissue samples were removed from 50 specimens collected from five sampling points located in the Xingu River basin. Fourteen organochlorine pesticides were analysed via gas chromatography with an electron capture detector (CG-ECD). Eight organochlorine pesticides were detected with average concentrations of ∑DDT, ∑Endossulfan and ∑HCH which were 26.17 ± 26.35, 14.38 ± 23.77 and 1.39 ± 8.46 ng g-1 in moisture content, respectively. DDT compounds were the most predominant, with a greater concentration of pp'-DDT in the liver and pp'-DDD in the muscle. Significant differences were noted between the types of tissues studied, and the concentration of OCPs varied between sampling sites.

Hair as a Biomarker of Long Term Mercury Exposure in Brazilian Amazon: A Systematic Review.

Many studies have assessed mercury (Hg) exposure in the Amazonian population. This article performs a literature search of the studies that used hair as a biomarker of Hg exposure in the Brazilian Amazonian population. The search covered the period from 1996 to 2016 and included articles which matched the following criteria: (1) articles related to Hg exposure into Brazilian Amazon; (2) articles that used hair as a biomarker of Hg exposure; (3) articles that used analytical tools to measure the Hg content on hair and (4) articles that presented arithmetic mean and/or minimum and maximum values of Hg. 36 studies were selected. The findings show that most of the studies were performed along margins of important rivers, such as Negro, Tapajós and Madeira. All the population presented mean levels of Hg on hair above 6 µg g-1 and general population, adults, not determined and men presented levels of Hg on hair above 10 µg g-1. The results show that most of the studies were performed by Brazilian institutions/researchers and the majority was performed in the State of Pará. The present study identified that Amazonian population has long-term been exposed to Hg. In terms of future perspectives, this study suggests the implementation of a strategic plan for environmental health surveillance in the region in order to promote health and benefit Amazonian population.

Quality index of the surface water of Amazonian rivers in industrial areas in Pará, Brazil.

In this study was to evaluate the waters quality of the Murucupi River, located in urban agglomerate area and intense industrial activity in Barcarena City, Pará State. The Arapiranga River in Abaetetuba City was used as control area (Background), next to Barcarena. Was used the Water Quality Index (WQI) based on nine variables analized. Waters quality of the Arapiranga and Murucupi rivers were regular to good and bad to good, respectively. Anthropogenic influence on the Murucupi River was higher, mainly by the disposal of domestic effluents from the urban agglomerate and of the industrial waste tailing basins upstream of this river. Due to its less inhabited environment and further away from the area urban and industrial, the Arapiranga River was more preserved. Waters pollution of around these area is increasingly intense, and restricted its uses for various purposes.

Comparison between Brain Computed Tomography Scan and Transcranial Sonography to Evaluate Third Ventricle Width, Peri-Mesencephalic Cistern, and Sylvian Fissure in Traumatic Brain-Injured Patients.

INTRODUCTION: Transcranial color-coded duplex sonography (TCCS) may help guide multimodal monitoring in the neurocritical setting. It may provide indirect information about intracranial hypertension, such as midline shift, third ventricle width, and peri-mesencephalic cistern obliteration. We aim to assess the agreement between brain computed tomography scan (CT scan) and TCCS in traumatic brain injury (TBI) patients. METHODS: In this retrospective cross-sectional observational study, TCCS was performed within 6 h before a brain CT scan. Only the first CT and TCCS after ICU admission were included. The agreement between the CT scan and TCCS was assessed by Bland-Altman plots and evaluating the intraclass correlation coefficient. RESULTS: Overall, 15 consecutive patients were included (80% male, 42 ± 23 years of age, Glasgow Coma Score 5 [4,6]). The mean difference between the brain CT scan and TCCS in measuring the midline shift was 0.30 ± 2.1 mm (intraclass correlation coefficient: 0.93; p < 0.01). An excellent correlation was also observed between the methods in assessing the third ventricle width (intraclass correlation coefficient: 0.88; p < 0.01). Bland-Altman plots did not show any systematic bias in either agreement analysis. TCCS showed good accuracy in predicting non-compressed peri-mesencephalic cisterns (AUC: 0.83, 95% CI 0.46-1.0) and the presence of the Sylvian fissure (AUC: 0.91, 95% CI 0.73-1.0) on CT scan. CONCLUSION: TCCS is a promising tool and may be an alternative to CT scans for evaluating TBI patients.

ß-Cell function improvements in grade I/II obese subjects with type 2 diabetes 1 month after biliopancreatic diversion: results from modeling analyses of oral glucose tolerance tests and hyperglycemic clamp studies.

OBJECTIVE: To investigate the effect of biliopancreatic diversion (BPD) surgery on ß-cell function in grade I and II obese patients with type 2 diabetes using oral and intravenous glucose loads. RESEARCH DESIGN AND METHODS: Sixty-eight women were divided into the following three groups: 19 lean-control (23.0 ± 2.2 kg/m(2)) and 18 obese-control (35.0 ± 4.8 kg/m(2)) subjects with normal glucose tolerance, and 31 obese patients with type 2 diabetes (36.3 ± 3.7 kg/m(2)). Of the 31 diabetic women, 64% underwent BPD (n = 20, BMI: 36.5 ± 3.7 kg/m(2)) and were reassessed 1 month after surgery. Oral glucose tolerance tests and hyperglycemic clamps were performed. Mathematical modeling was used to analyze basal and stimulated ß-cell function, insulin sensitivity (IS), hepatic extraction (HE) of insulin, and delay time of ß-cell response to a specific plasma glucose concentration. RESULTS: After BPD, restoration of the basal disposition index (P < 0.001) and improvement of the stimulated disposition indices in oral and intravenous glucose stimulation of the ß-cell were observed (P < 0.05). In both dynamic tests, there were no changes in the delay time of ß-cell response. IS for oral glucose stimulation (IS(oral)) and intravenous clamp glucose stimulation (IS(clamp)) was completely normalized (P < 0.001). IS(oral) and IS(clamp) increased approximately 5.0-fold and 3.5-fold, respectively (P < 0.01). The HE of insulin increased in the basal (P < 0.05) and stimulated states (P < 0.01). CONCLUSIONS: ß-Cell function, IS, and HE of insulin improved after BPD, which improved glycemic control.