Migration in French Guiana: Implications in health and infectious diseases.

In French Guiana, more than a third of the population, and nearly half of the adults, are of foreign origin. This immigration is explained by the French standard of living, which is attractive to nationals of surrounding countries. Infectious diseases remain in the top 10 causes of premature death, often in the most precarious populations. In this context we aimed to synthesize the state of the knowledge regarding immigration and infectious diseases in French Guiana and the general implications that follow this diagnosis. For HIV, although the majority of patients are of foreign origin, estimates of the presumed date of infection based on CD4 erosion modelling and from molecular analyses suggest that the majority of transmissions in foreign-born individuals occur in French Guiana and that the Guiana shield has been a crossroad between Latin America and the Caribbean. Among key populations bridging these regions illegal gold miners are very mobile and have the greatest proportion B Caribbean HIV viruses. Gold miners have been a key vulnerable population for falciparum malaria and other tropical diseases such as leishmaniasis, leprosy, or leptospirosis. The complex history of migrations in French Guiana and on the Guiana Shield is also reflected in the fingerprinting of mycobacterium tuberculosis and the high incidence of tuberculosis in French Guiana, notably in immigrants, reflects the incidences in the countries of origin of patients. The high burden of infectious diseases in immigrants in French Guiana is first and foremost a reflection of the precarious living conditions within French Guiana and suggests that community-based proactive interventions are crucial to reduce transmission, morbidity, and mortality from infectious diseases.

From an interventional study to a national scale-up: lessons learned from the Malakit strategy at the French Guiana-Suriname border.

Scaling-up an experimental intervention is always a challenge. On the border between French Guiana, Brazil and Suriname, an interventional study demonstrated the effectiveness of distributing self-diagnosis and self-treatment kits (Malakits) to control malaria in mobile and hard-to-reach populations. Its integration into the Suriname's National Malaria Elimination Plan after a 2-year experiment faced numerous challenges, including human resources to cope with the additional workload of coordinators and to maintain the motivation of community health workers. The economic recession in Suriname, the Covid pandemic, and logistical issues also hampered the scale-up. Finally, thanks to the commitment of stakeholders in Suriname and French Guiana, the integration of Malakit distribution into the Surinamese national programme was proved possible.

Habitat area and edges affect the length of trophic chains in a fragmented forest.

The food chain length represents how much energy reaches different trophic levels in food webs. Environmental changes derived from human activities have the potential to affect chain length. We explore how habitat area and edges affect chain length through: (1) a bottom-up effect of abundance ('pyramid hypothesis'); (2) the truncation of the highest trophic level ('trophic-rank hypothesis'); and (3) changes in species connectivity patterns ('connectivity hypothesis'). We built plant-leaf miner-parasitoid food webs in 19 remnants of a fragmented Chaco forest from central Argentina. On each remnant, we constructed food webs from different locations at the forest interior and edges. For each food web, we registered the abundance of species, the species richness of each trophic level, estimated the connectivity of their networks, and the average food chain length. We used structural equation models to evaluate the direct and indirect effects of habitat area and edge/interior location on food chain length mediated by species richness, abundance and connectivity. We found no direct effects of habitat area on chain length but chains were longer at forest edges than at their interior. The three mechanisms were supported by our results, although they showed different strengths. First, we found that the interior favours a bottom-up abundance effect from herbivores to parasitoids that positively affected chain length; second, we found that the forest area positively affects plant richness, which has a strong effect on the number of resources used by consumers, with a positive effect on chain length. Third, the remnant area and interior position favoured plant richness with a negative effect on the abundance of parasitoids, which had a positive effect on chain length. In general, the strongest effects on chain length were detected through changes in abundance rather than species richness although abundance was less affected by habitat fragmentation. We evaluated for the first time the effects of human-driven habitat fragmentation on the length of trophic chains in highly diverse plant-herbivore-parasitoid networks. Despite the loss of species, small habitat fragments and edges embedded in the agricultural matrix can support interaction networks, making them conservation targets in managed landscapes.

El largo de cadenas tróficas representa cuanta energía alcanza diferentes niveles tróficos en redes tróficas. Los cambios ambientales producto de las actividades humanas tienen el potencial de afectar el largo de las cadenas tróficas. Exploramos como el área de hábitat y los bordes afectan el largo de cadenas tróficas a través de: (1) un efecto ascendente de la abundancia ('hipótesis pirámide'); (2) el truncamiento del nivel trófico superior ('hipótesis de ranking trófico'); y (3) cambios en los patrones de conectividad ('hipótesis de conectividad'). Construimos redes tróficas entre plantas-minadores de hoja-parasitoides en 19 remanentes de bosque Chaqueño serrano altamente fragmentado en el centro de Argentina. Para cada remanente construimos redes tróficas en distintas ubicaciones en el borde e interior del bosque. Para cada red trófica registramos la abundancia media de las especies, la riqueza de cada nivel trófico, estimamos la conectividad de las redes y el largo de cadenas tróficas promedio. Utilizamos modelos de ecuaciones estructurales para evaluar los efectos directos e indirectos del área y la ubicación borde/interior sobre el largo de cadenas tróficas mediado por la riqueza de especies, la abundancia y la conectividad. No encontramos efectos directos del área de hábitat sobre el largo de cadenas, pero las cadenas fueron más largas en los bordes que en el interior. Los tres mecanismos propuestos fueron apoyados por los resultados, pero mostraron distinta fuerza. Primero, encontramos que el interior de los bosques favorece los efectos ascendentes de la abundancia desde los herbívoros a los parasitoides lo que afectó positivamente al largo de las cadenas; segundo, encontramos que el área de bosque afectó positivamente a la riqueza de especies, lo que tuvo un efecto positivo en el largo de cadenas. Tercero, el área de bosque remanente y la ubicación en el interior favorecieron la riqueza de plantas, influyendo negativamente en la abundancia de parasitoides lo que tuvo un efecto positivo en el largo de cadenas. En general, los efectos más fuertes sobre el largo de cadenas se detectaron a través de cambios en la abundancia más que en la riqueza, aunque la abundancia fue menos afectada por la fragmentación del hábitat que la riqueza de especies. En este estudio evaluamos por primera vez los efectos de la fragmentación del hábitat por causas humanas sobre el largo de cadenas tróficas en redes tróficas altamente diversas de plantas, herbívoros y parasitoides. A pesar de la pérdida de especies, los fragmentos pequeños y los bordes de bosque inmersos en una matriz agrícola pueden sostener redes de interacciones, convirtiéndolos en objetivos de conservación en paisajes manejados.

Determination of methylmercury and inorganic mercury in human hair samples of individuals from Colombian gold mining regions by double spiking isotope dilution and GC-ICP-MS.

With the aim to distinguish between routes of exposition to mercury (Hg) in artisanal and small-scale gold mining (ASGM) communities and to distinguish between Hg contamination sources, Hg species composition should be performed in human biomarkers. In this work, Hg species-specific determination were determined in human hair samples (N = 96), mostly non-directly occupied in ASGM tasks, from the six most relevant gold mining Colombian regions. Therefore, MeHg, Hg(II) and THg concentrations were simultaneously determined by double spiking species-specific isotope dilution mass spectrometry (IDMS) and GC-ICP-MS. Only 16.67% of participants were involved at some point in AGSM works and fish consumption ranged from 3 to 7 times/week, which is between medium and high intake levels. The median concentration of THg obtained from all samples is higher than the reference dose weekly acceptable of MeHg intake established by the EPA (1 ppm), whereas a 25% were more than 4 times higher than the WHO level (2.2 µg Hg g-1). Median THg value of individuals consuming fish 5-7 times per week was significantly higher (p < 0.05) than those of the other consuming groups (12.5 µg Hg g-1). Most of the samples presented a % of MeHg relative to THg higher than 80%. The average % of Hg(II)/THg was 11% and only 10 individuals presented a Hg(II) content over 30%. No significant differences (p > 0.05) were found when the amount of Hg(II) was compared between people involved in AGSM task and people not involved. Interestingly, significant differences among the evaluated groups where found when the percentage of the Hg(II)/THg ratio of these groups were compared. In fact, people involved in AGSM tasks showed 1.7 times higher Hg(II)/THg vs. inhabitants uninvolved. This suggest that Hg(II) determination by IDMS-GC-ICP-MS could be a good proxy for evaluating Hg(II) adsorption by direct exposure to mercury vapors onto hair.

Artisanal Gem Mining in Brazil: A Source of Genotoxicity and Exposure to Toxic Elements.

Environmental and occupational exposure to toxic metals has led many people around the world to have serious health problems. Mining activities contribute to an increased risk of exposure to these elements. In this work, a study of environmental biomonitoring and routes of exposure to toxic metals in a region of artisanal mining was performed. This study was carried out in the district of Taquaral de Minas, located in the Jequitinhonha Valley in the state of Minas Gerais. The valley is one of the wealthiest and highest gem-producing areas in Brazil. Five artisanal mines were sampled (Bode, Pirineu, Pinheira, Lajedo, and Marmita). Several potentially toxic metals (Be, Zn, Mn, Ba Cd, Hg, and U) were investigated in the soils and dust over the rocks and the soils. Samples from 22 individuals occupationally exposed and 17 unexposed persons, who formed the reference group, were analyzed for trace elements by an inductively coupled plasma mass spectrometer. The genotoxicity was evaluated by the micronucleus test in buccal mucosa epithelial cells, where the following changes were scored: micronuclei (MN) binucleate (BN) cells and kariolytic (KL) cells. The MN test showed significantly increased frequencies in all alterations of exposed individuals compared to the controls (p < 0.05, Student's t-test). The urine analysis showed levels of Cr, Ni Ba, Pb, and As in the blood, which were higher than the ATSDR recommended levels. The association between the MN test and the trace element concentrations found in the blood and urine was significant (p < 0.05). The higher the number of years of working, the higher the concentrations in the blood were, due to chronic exposure. The results of the present study indicate environmental contamination and a potential risk to the health of miners, suggesting an intervention.

The influence of fatigue on work capacity and quality of life among miners with silicosis.

Introduction: Factors associated with the mining environment can contribute to work accidents and reduced caution at work, which may affect the quality of life and work capacity of miners. Objectives: To evaluate if fatigue influences quality of life and work capacity in miners with silicosis. Methods: This was a cross-sectional study conducted in the Northern Region of the state of Rio Grande do Sul, Brazil. Sociodemographic data and data on fatigue, work capacity, and quality of life were collected during the second half of 2017 and first half of 2018. Results: All participants were men. Mean participant age was 52.6 (± 7.2) years, and most (70.4%) of them did not finish elementary school. The strongest correlations were found between the physical, overall, and total fatigue domains and the World Health Organization Quality of Life - BREF and between the total and mental fatigue domains and the Work Ability Index. Strong correlations were also found between overall and total fatigue and the total St. George's Respiratory Questionnaire score. Conclusions: Silicosis and physical workload have a negative impact on respiratory quality of life and perception of fatigue among miners.

Introdução: Fatores associados ao ambiente de mineração podem contribuir para acidentes e menor autocuidado no trabalho, podendo afetar a qualidade de vida e a capacidade para o trabalho. Objetivos: Avaliar se a fadiga influencia a qualidade de vida e a capacidade para o trabalho dos trabalhadores de mineração com silicose. Métodos: Trata-se de estudo transversal, desenvolvido no norte do Rio Grande do Sul, Brasil. Foram coletados dados so cio demográficos, de fadiga, da capacidade para o trabalho e de qualidade de vida. A coleta de dados ocorreu durante o segundo semestre de 2017 e o primeiro semestre de 2018. Resultados: Todos os participantes eram homens. A idade média dos participantes foi de 52,6 (± 7,2) anos, e a maioria (70,4%) não concluiu o ensino fundamental. Os melhores coeficientes de correlação foram alcançados entre os domínios de fadiga física, geral e total e o questionário de Qualidade de Vida da Organização Mundial da Saúde-BREF e entre os domínios totais e fadiga mental e o Índice de Capacidade para o Trabalho. Correlações fortes também foram alcançadas entre a fadiga geral e total e o escore total do Questionário de Qualidade de Vida Respiratória do Hospital São Jorge. Conclusões: A silicose e a carga de trabalho física têm influência negativa na qualidade de vida respiratória e na percepção de fadiga dos trabalhadores de mineração.

Adverse Health Effects and Mercury Exposure in a Colombian Artisanal and Small-Scale Gold Mining Community.

The aim of this study was, first of all, to associate the mercury (Hg) concentrations and respiratory functions of the gold miners in the artisanal small-scale gold mining (ASGM) environment in San Martín de Loba, Colombia. We carried out a cross-sectional study using a survey whereby we collected basic demographic information, occupational medical history, and applied two validated questionnaires (Q16 and SF36). We measured Hg levels in all volunteers using direct thermal decomposition-atomic absorption spectrometry. Univariate and bivariate statistical analyses were carried out for all variables, performing logistic regression to assess the effect of ASGM on health outcomes. Volunteers enrolled (n = 124) were between the ages of 20 and 84 years (84% miners and 79% males). No changes were found in the systolic blood pressure, diastolic blood pressure, and heart rate from the ASGM miners, in crude and adjusted statistical analyses. ASGM miners increased 8.91 (95% confidence interval, 1.55-95.70) times the risk of having these than of having neurotoxic effects. Concentrations of total whole blood mercury (T-Hg) in all participants ranged from 0.6 to 82.5 with a median of 6.0 µg/L. Miners had higher T-Hg concentrations than non-miners (p-value = 0.011). Normal and abnormal respiratory spirometry patterns showed significant differences with the physical role and physical function of quality-of-life scales (the (p-value was 0.012 and 0.004, respectively). The spirometry test was carried out in 87 male miners, with 25% of these miners reporting abnormalities. Out of these, 73% presented a restrictive spirometry pattern, and 27%, an obstructive spirometry pattern. The ASGM population had higher Hg concentrations and worse neurotoxic symptomatology than non-miners of the same community.

Volume-based tomography for the diagnosis of incipient silicosis in former gold miners.

OBJECTIVE: To evaluate silicosis diagnosed through CT, with integration of clinical-occupational data, in silica-exposed workers presenting chest X-rays within International Labor Organization (ILO) category 0. METHODS: Cross-sectional study with 339 former gold miners, with comparable exposures and X-rays classified as ILO subcategory 0/0 (n=285) and 0/1 (n=54) were submitted to volume-based CT. The findings were classified according to the International Classification of HRCT CT for Occupational and Environmental Respiratory Diseases. RESULTS: A profusion degree of round opacities (RO)>1 was found in 22.4% (76/339) of the CT exams. After integrating the CT findings with clinical and occupational data, silicosis was diagnosed as follows: 43/285 (15.1%) and 14/54 (25.9%) in workers whose X-rays had been classified as 0/0 and 0/1, respectively. There was an upward trend towards longer exposures, reaching 38.9% when working more than 10 years underground and classified as 0/1 (p=0019). Those with presence of RO whose final diagnosis was not silicosis were mainly cases of tuberculosis or 'indeterminate nodules'. Emphysema was found in 65/339 (19.1%), only 5 being detected in the X-ray. CONCLUSION: Volume-based CT proved to be useful in the investigation of silicosis among individuals with a relevant exposure to silica, capturing diagnoses that had not been identified on X-rays. A response gradient of silicosis was showed by CT even in this population with ILO category 0 radiographs. It can be indicated based on quantitative and/or qualitative criteria of occupational exposure, especially considering the possibilities of low CT dosage.

High altitude underground mining. Acclimatization and possible toxicological risks.

SUMMARY: Background. Aim of our study was to measure the first responses to hypobaric hypoxia: changes in ventilation minute, heart rate, and hemoglobin saturation which are important parameters involved in the health of mine-workers at high-altitude. Material and Methods. We develop a study of parameters mentioned on Chilean miners working in an underground mine at high altitude, between 3.070 and 3.656 masl, in an unusual shift system consisting of 12-hour daily work during 4 days, and consecutive 4 resting days. The results obtained at high altitude are contrasted with the corresponding for clerks working at 800 masl. Results. Either miners who has work less than 6 months at HA as those who are exposed at their workplace to contaminants, as diesel and others, show Hemoglobin Saturation below 90%. Heart Rate increases in response to exposure to acute and/or chronic hypoxia at high altitude. Miners during their resting period at 800 masl or less show an average heart rate lower than clerks no exposed to high altitude. Average Minute Volume of miners at high altitude, on each and every day of the shift, is higher than the mean volume of clerks at 800 masl. Conclusions. The most of studied miners present acclimatization responses at high altitude in all the studied parameters. The increase in Minute Volume implies a risky condition due to the increase of inhaled toxic inherent to the production process. It appears as an urgency to study the combined effects of hypobaric at high altitude and toxics present at the underground mine.

Riesgo por exposición a agentes químicos y atmósferas explosivas en minas de carbón de Tópaga, Colombia / Risk due to exposure to chemical agents and explosive atmospheres in the coal mines of Tópaga, Colombia / Risco de exposição a agentes químicos e atmosferas explosivas em minas de carvão em Topaga, Colômbia

RESUMEN Se realizó un estudio observacional de corte transversal con enfoque descriptivo con el objetivo de determinar el riesgo por exposición a agentes químicos, atmósferas peligrosas y definir recomendaciones para mejorar las condiciones de trabajo en las minas de carbón de Tópaga (Boyacá). Para recopilar la información se utilizó el cuestionario para la identificación y prevención del riesgo en espacios confinados, del Instituto Nacional de Seguridad e Higiene en el Trabajo, y se realizaron mediciones de gases en las minas. Los resultados muestran que el 25% de las minas tienen niveles de oxígeno inferiores a 19,5% y ninguna supera el límite de explosividad. El 15% supera el Valor Límite Permisible (VLP) de monóxido de carbono y el 20% supera el VLP de sulfuro de hidrógeno y dióxido de azufre. Entre las recomendaciones propuestas se encuentra favorecer la ventilación natural, aplicar ventilación forzada cuando la natural resulte insuficiente y el empleo de calzado y herramientas antichispa. Se concluye que, en general, las condiciones de trabajo en las minas son inadecuadas para la seguridad y salud de los mineros.

ABSTRACT An observational cross-sectional study with a descriptive approach was carried out with the objective of determining the risk due to exposure to chemical agents, dangerous atmospheres and defining recommendations to improve working conditions in the coal mines of Tópaga (Boyacá). During the data collection process was used the questionnaire for the identification and prevention of risk in confined spaces, of the National Institute of Safety and Hygiene at Work. Moreover gas measurements were made in the mines. The results show that 25% of the mines have oxygen levels below 19.5% and none exceed the explosive limit. 15% exceed the Permissible Limit Value (VLP) for carbon monoxide and 20% exceed the VLP for hydrogen sulfide and sulfur dioxide. The proposed recommendations include favoring natural ventilation, applying forced ventilation when the natural one is insufficient and the use of non-sparking shoes and tools. It is concluded that, in general, the working conditions in the mines are inadequate for the safety and health of the miners.

RESUMO Foi realizado um estudo observacional transversal com abordagem descritiva com o objetivo de determinar o risco devido à exposição a agentes químicos, atmosferas perigosas e definir recomendações para melhorar as condições de trabalho nas minas de carvão de Tópaga em Boyacá. Para colher as informações, foi utilizado o questionário de identificação e prevenção de riscos em espaços confinados, do Instituto Nacional de Segurança e Higiene no Trabalho, e realizaram medidas do nível dos gases nas minas visitadas. Os resultados mostram que 25% das minas apresentam níveis de oxigênio abaixo de 19,5% e nenhuma excede o limite explosivo. 15% excedem o valor limite permitido (VLP) para o monóxido de carbono e 20% excedem o VLP para o sulfeto de hidrogênio e dióxido de enxofre. Entre as recomendações propostas estão favorecer a ventilação natural, aplicar ventilação forçada quando a ventilação natural for insuficiente e o uso de calçados e ferramentas anti-faísca. Conclui-se que, em geral, as condições de trabalho nas minas são inadequadas para a segurança e a saúde dos mineiros.

Perceptions about malaria among Brazilian gold miners in an Amazonian border area: perspectives for malaria elimination strategies.

BACKGROUND: Mining in the Amazon exposes gold miners to various diseases, including malaria, whose control is still a major challenge. The environment of the mines contributes to the proliferation of vector mosquitoes and the precarious housing conditions facilitate transmission of the disease. Understanding gold miners' perceptions is essential for the formulation of strategies to fight malaria. A qualitative study was carried out in the municipality of Calçoene, state of Amapá, Brazilian Amazon adjointining the municipality of Oiapoque, that is in the border area with French Guiana and Suriname. METHODS: A semi-structured interview was applied to an intentional sample of 29 miners, a number determined by the theoretical saturation criterion. Thematic analysis was adopted to obtain the results and the Cohen's Kappa index was calculated to verify the agreement between observers during coding. RESULTS: The agreement between observers was verified by a Cohen's Kappa index of 0.82. Analysis of the interviews showed that gold miners were subjected to prejudice from the community due to forest diseases that they can transmit, and their activities are often associated with crime. When the miners return to their hometown after a period of mining, the urban population blames them for the onset of diseases such as malaria. Most participants in the survey did not know how malaria transmission occurs, and associated its occurrence with contaminated water and food. Participants reported not being afraid of the disease, trusting the diagnosis and available treatment, though this depends on where they are treated. The use of therapeutic resources, such as medicinal plants and medicines acquired in the illegal market, is very common in this population. Despite the challenges identified by the research subjects, they believe that the disease can be controlled, or the cases reduced, but there was low acceptability for a possible mass drug administration (MDA) intervention. CONCLUSION: Despite a recent reduction in malaria prevalence in Brazil, there are still vulnerable populations, such as gold miners, who help to perpetuate the existence of the disease in the Amazon. The lack of knowledge regarding how the transmission of malaria occurs, associated with myths regarding this and the use of traditional health practices and illegal drugs for the treatment of the disease without a specific diagnosis, jeopardizes the country's efforts to eliminate malaria. It is necessary to implement control programmes in these populations, especially those who frequently travel around the border region and to remote locations, which are difficult regions for health teams to access, thus hindering diagnostic and treatment actions. For this reason, understanding the perceptions of these individuals as well as their customs, beliefs and lifestyle, can assist in the production of targeted educational material and adoption of strategies in the elimination of malaria in the country.

Effects of chronic intermittent hypobaric hypoxia on prostate-specific antigen (PSA) in Chilean miners.

OBJECTIVE: The aim was to determine the effects of chronic intermittent hypobaric hypoxia (CIHH) on prostate-specific antigen (PSA) levels in Chilean miners who work at different altitudes. METHODS: A cross-sectional study was conducted between April and July 2019. Miners from five mines (N=338) at different altitudes were evaluated. We recorded sociodemographic, working and altitude information. Haemoglobin oxygen saturation (SaO2) and haemoglobin (Hb) were measured in situ, while PSA and testosterone were analysed at a low level. Linear mixed-effect models were used to evaluate the association between PSA level and two CIHH exposures: composite CIHH (with four descriptors) and ChileStd-CIHH (CIHH Chilean standard; based on the Chilean technical guide for occupational exposure to CIHH). All models were adjusted by age, body mass index and day of the work the samples were taken. RESULTS: Highest and lowest PSA levels were found in mines ≥3000 m above sea level (mine 3: median=0.75, IQR=-0.45; mine 4: median=0.46, IQR=-0.35). In the multilevel models, the wider altitude difference between mining operation and camp showed lower PSA levels (model D: ßPSA=-0.93 ng/mL, ßlogPSA=-0.07, p<0001), adjusted for other CIHH descriptors, SaO2, Hb and testosterone. The descriptors of composite CIHH explained better PSA variations than ChileStd-CIHH (model D: marginal R2=0.090 vs model A: marginal R2=0.016). CONCLUSIONS: Occupational health regulations and high altitude medicine should consider these results as initial evidence on the inclusion of new descriptors for CIHH and the possible effect of this exposure on PSA levels in this male-dominated occupational sector.

Effects of climate, seasonality, and parasitoid abundance on Liriomyza Mik (Diptera: Agromyzidae) populations on important crops in Northeastern Brazil

Agromyzidae (Insecta: Diptera) is a cosmopolitan family of acalyptrate flies, with almost 3,000 species worldwide distributed. Most species are leaf miners on a large number of plants. Among them, Liriomyza Mik, 1894 is a large genus of leaf-miner species that can cause significant damage to economically important crops and is considered agricultural pests, such as Liriomyza sativae Blanchard, 1938 and Liriomyza huidobrensis (Blanchard, 1926), which are herein investigated. The present study deals with the impact of climatic factors (temperature, humidity, and precipitation), seasonality, and parasitoid abundance on leaf-miner infestation during one year in five cultivated crops in Northeastern Brazil. Climatic factors for instance had different effects on L. sativae populations in melon and watermelon crops. Larval abundances were greater during the dry season for both species, L. sativae and L. huidobrensis, and abundance of adult parasitoids followed the increase of mining larvae.(AU)

Effects of climate, seasonality, and parasitoid abundance on Liriomyza Mik (Diptera: Agromyzidae) populations on important crops in Northeastern Brazil

Agromyzidae (Insecta: Diptera) is a cosmopolitan family of acalyptrate flies, with almost 3,000 species worldwide distributed. Most species are leaf miners on a large number of plants. Among them, Liriomyza Mik, 1894 is a large genus of leaf-miner species that can cause significant damage to economically important crops and is considered agricultural pests, such as Liriomyza sativae Blanchard, 1938 and Liriomyza huidobrensis (Blanchard, 1926), which are herein investigated. The present study deals with the impact of climatic factors (temperature, humidity, and precipitation), seasonality, and parasitoid abundance on leaf-miner infestation during one year in five cultivated crops in Northeastern Brazil. Climatic factors for instance had different effects on L. sativae populations in melon and watermelon crops. Larval abundances were greater during the dry season for both species, L. sativae and L. huidobrensis, and abundance of adult parasitoids followed the increase of mining larvae.

Effects of climate, seasonality, and parasitoid abundance on Liriomyza Mik (Diptera: Agromyzidae) populations on important crops in Northeastern Brazil

ABSTRACT Agromyzidae (Insecta: Diptera) is a cosmopolitan family of acalyptrate flies, with almost 3,000 species worldwide distributed. Most species are leaf miners on a large number of plants. Among them, Liriomyza Mik, 1894 is a large genus of leaf-miner species that can cause significant damage to economically important crops and is considered agricultural pests, such as Liriomyza sativae Blanchard, 1938 and Liriomyza huidobrensis (Blanchard, 1926), which are herein investigated. The present study deals with the impact of climatic factors (temperature, humidity, and precipitation), seasonality, and parasitoid abundance on leaf-miner infestation during one year in five cultivated crops in Northeastern Brazil. Climatic factors for instance had different effects on L. sativae populations in melon and watermelon crops. Larval abundances were greater during the dry season for both species, L. sativae and L. huidobrensis, and abundance of adult parasitoids followed the increase of mining larvae.

Cyanide Contamination of the Puyango-Tumbes River Caused by Artisanal Gold Mining in Portovelo-Zaruma, Ecuador.

PURPOSE OF REVIEW: To examine cyanide (CN-) contamination of a large river in southeastern Ecuador that has been severely impacted by the indiscriminate discharge of untreated gold processing effluents. RECENT FINDINGS: Poor environmental stewardship of cyanide (CN-) use by 87 gold processing centers in Portovelo-Zaruma in southern Ecuador to leach residual gold from Hg-contaminated tailings has resulted in high CN- contamination of the Puyango-Tumbes River downstream from the centers. Free CN- concentrations were high in river surface waters for 50 km below the processing plants, with the highest concentration 9088 times above the CCME standard of 5 µg/L and 1136 times above the 24-h LC50 concentration of 40 µg/L free CN- for some fish species. Due to cyanidation of mercury-contaminated tailings, the formation of Hg-CN complexes is a grave concern, as these complexes have been shown to be highly bioavailable. Preliminary tests conducted in a laboratory using bioassays with Danio rerio sp. and varying concentrations of synthetic Hg(CN)2 salt have shown significant THg bioaccumulation in muscle and kidney fish tissues exposed to concentrations >0.12 mg/L. Furthermore, low MeHg results in fish tissues demonstrated little occurrence of methylation and that the bulk of the total mercury content was in the form of inorganic mercury. Although construction of a communal tailings facility (CTF) in Portovelo is a positive development to reduce riverine pollution, the requirement to truck tailings up to the CTF likely results in inadequate compliance of environmental regulations that are poorly enforced.

The impact of imported malaria by gold miners in Roraima: characterizing the spatial dynamics of autochthonous and imported malaria in an urban region of Boa Vista

BACKGROUND The number of malaria cases in Roraima nearly tripled from 2016 to 2018. The capital, Boa Vista, considered a low-risk area for malaria transmission, reported an increasing number of autochthonous and imported cases. OBJECTIVES This study describes a spatial analysis on malaria cases in an urban region of Boa Vista, which sought to identify the autochthonous and imported cases and associated them with Anopheles habitats and the potential risk of local transmission. METHODS In a cross-sectional study at the Polyclinic Cosme e Silva, 520 individuals were interviewed and diagnosed with malaria by microscopic examination. Using a global positional system, the locations of malaria cases by type and origin and the breeding sites of anopheline vectors were mapped and the risk of malaria transmission was evaluated by spatial point pattern analysis. FINDINGS Malaria was detected in 57.5% of the individuals and there was a disproportionate number of imported cases (90.6%) linked to Brazilian coming from gold mining sites in Venezuela and Guyana. MAIN CONCLUSIONS The increase in imported malaria cases circulating in the west region of Boa Vista, where there are positive breeding sites for the main vectors, may represent a potential condition for increased autochthonous malaria transmission in this space.

Discovery of leaf-mining Tischeriidae (Lepidoptera) in Colombia and their distribution in the Neotropics.

This is the first report of the family Tischeriidae in Colombia. We describe two new species recently discovered in the department of Valle del Cauca in southwestern Colombia: Astrotischeria ochrimaculosa Diskus, Stonis Vargas, sp. nov., and A. colombiana Stonis Vargas, sp. nov. The latter is a leaf miner of Asteraceae, while A. ochrimaculosa is trophically associated with Malvaceae. Astrotischeria colombiana is known only from Colombia, but A. ochrimaculosa is more widely distributed from Colombia to Peru. The new species are illustrated with photographs of their habitats, adults, male and female genitalia, and leaf mines. We comment on the rarity of tischeriids in collections and their current known distribution in the Neotropics.

Aerobic Capacity, Lactate Concentration, and Work Assessment During Maximum Exercise at Sea Level and High Altitude in Miners Exposed to Chronic Intermittent Hypobaric Hypoxia (3,800 m).

We previously showed that arterial oxygen content during maximum exercise remains constant at high altitude (HA) in miners exposed to chronic intermittent hypobaric hypoxia (CIHH). Nevertheless, information about VO2, lactate concentration [Lac], and work efficiency are absent in this CIHH miner population. Our aim was to determine aerobic capacity, [Lac], and work efficiency at sea level (SL) and HA during maximum exercise in miners acclimatized to CIHH at 3,800 m. Eight volunteer miners acclimatized to CIHH at HA (> 4 years) performed an exercise test at SL and HA. The test was performed on the 4th day at HA or SL and consisted of three phases: Rest (5 min); Exercise test, where the load was increased by 50 W every 3 min until exhaustion; and a Recovery period of 30 min. During the procedure VO2, transcutaneous arterial saturation (SpO2, %), and HR (bpm) were assessed at each step by a pulse oximeter and venous blood samples were taken to measure [Lac] and hemoglobin concentration. No differences in VO2 and [Lac] in SL vs. HA were observed in this CIHH miner population. By contrast, a higher HR and lower SpO2 were observed at SL compared with HA. During maximum exercise, a reduction in VO2 and [Lac] was observed without differences in intensity (W) and HR. A decrease in [Lac] was observed at maximum effort (250 W) and recovery at HA vs. SL. These findings are related to an increased work efficiency assessment such as gross and net efficiency. This study is the first to show that miners exposed to CIHH maintain their work capacity (intensity) with a fall in oxygen consumption and a decrease in plasmatic lactate concentration at maximal effort at HA. These findings indicate that work efficiency at HA is enhanced.