Investigation on the mancozeb toxicity in adult zebrafish (Danio rerio).

Agriculture has gained increasing importance in response to the continuous growth of the world population and constant need for food. To avoid production losses, farmers commonly use pesticides. Mancozeb is a fungicide used in agriculture as this compound is effective in combating fungi that harm crops. However, this fungicide may also produce damage to non-target organisms present in soil and water. Therefore, this study aimed to investigate the influence of exposure to mancozeb on survival rate, locomotor activity, behavior, and oxidative status utilizing adult zebrafish (Danio rerio) as a model following exposure to environmentally relevant concentrations of this pesticide. The experimental groups were negative control, positive control, and mancozeb (0.3; 1.02; 3.47; 11.8 or 40 µg/L). Zebrafish were exposed to the respective treatments for 96 hr. Exposure to mancozeb did not markedly alter survival rate and oxidative status of Danio rerio. At a concentration of 11.8 µg/L, the fungicide initiated changes in locomotor pattern of the animals. The results obtained suggest that the presence of mancozeb in the environment might produce locomotor alterations in adult zebrafish, which subsequently disrupt the animals' innate defense mechanisms. In nature, this effect attributed to mancozeb on non-target organisms might result in adverse population impacts and ecological imbalance.

Epidemiological profile, temporal analysis, and future projections of suicide cases in rural cities in the extreme south of Brazil.

The present study aimed to verify the time series (2000-2017) of death rates by suicide and its associated factors in 4 municipalities in the extreme south of Brazil. Data were obtained through the analysis of medical reports and police report bulletins at the Instituto Médico Legal, in the city of Rio Grande. The suicide rate in the Rio Grande region varied from 4 to 11 suicides per 100,000 inhabitants and it is estimated that by 2030 this rate could reach 16.5 suicides per 100,000 inhabitants. The rural cities of Santa Vitória do Palmar and Chuí present even higher suicide averages when compared to Rio Grande, the most populous city of the four. The death rate from suicide increased gradually in the period analyzed, with the prevalence rising among the youngest and the elderly population. A more comprehensive understanding of the influences of environmental issues on suicidal decisions constitutes an important action that needs to be taken, both because of regional vulnerabilities and the target population identified. Evidence indicates that knowledge of factors affecting individuals residing in this Brazilian region where increased suicide rates are recorded needs to be recognized as a priority.

Oxidative damage in the Vesper mouse (Calomys laucha) exposed to a simulated oil spill-a multi-organ study.

Small wild mammals have been used to measure the damage caused by exposure to oil-contaminated soil, including deer mice. However, the study of toxic effects of crude oil using oxidative damage biomarkers in the wild rodent Calomys laucha (Vesper mouse) is absent. This investigation aimed to evaluate the effects of acute exposure to contaminated soil with different concentrations of crude oil (0, 1, 2, 4 and 8% w/w), simulating an accidental spill, using oxidative stress biomarkers in the liver, kidneys, lungs, testes, paw muscle, and lymphocytes of C. laucha. Animals exposed to the contaminated soil showed increases in lipid peroxidation and protein carbonylation at the highest exposure concentrations in most organ homogenates analyzed and also in blood cells, but responses to total antioxidant capacity were tissue-dependent. These results showed that acute exposure to oil-contaminated soil caused oxidative damage in C. laucha and indicate these small mammals may be susceptible to suffer the impacts of such contamination in its occurrence region, threatening the species' survival.

2030 Agenda: discussion on Brazilian priorities facing air pollution and climate change challenges.

The advance of human activities in a disorderly way has accelerated in recent decades, intensifying the environmental impacts directly linked to these practices. The atmosphere, essential for the maintenance of life, is increasingly saturated with pollutants, offering risks to practically all the inhabitants of the planet, a process that, in addition to causing illness and early mortality, is related to serious financial losses (including in the production of goods), dangerous temperature increase and severe natural disasters. Although this perception is not recent, the global initiative to control the different mechanisms that trigger the commitment of biodiversity and irreversible climate changes arising from pollution is still very incipient, given that global initiatives on the subject emerged just over 50 years ago. Brazil is a territory that centralizes many of these discussions, as it still faces both political and economic obstacles in achieving a sustainable growth model as it was agreed through the United Nations 2030 Agenda. Even though there is little time left for the completion of these goals, much remains to be done, and despite the fulfillment of this deadline, the works will certainly need to be extended for much longer until an effective reorientation of consciousness occurs. Scientific researches and discussions are fundamental tools to the understanding of issues still little explored in this field.

Better understanding the behavior of air pollutants at shutdown times - results of a short full lockdown.

Numerous studies have evaluated the effects of lockdowns during the COVID-19 pandemic, but most of them have concerned large cities and regions. This study aimed to evaluate the dynamics of air pollutants during and after the implementation of a short lockdown in the medium-sized city of Pelotas, Brazil, using hourly measurements of pollutants. The evaluation period included in this study was between August 9th and 12th, 2020. A machine learning model was used to investigate the expected behavior against what was observed during the study period. All pollutants presented a gradual reduction until a dynamic plateau established 48 hours after the start of the lockdown: NO2 (↓4%), O3 (↓34%), SO2 (↓24%), CO (↓48%), PM10 (↓82%) and PM2.5 (↓82%). At the end of the restriction measures, the PM10 and PM2.5 levels continued to decline beyond expectations. Our findings show that these measures can positively affect the air quality in medium-sized cities.

Gestational and Neonatal Outcomes in Cities in the Largest Coal Mining Region in Brazil.

Brazil has one of the largest mineral coal reserves in the world. More than 40% of this ore is in the Candiota Mine, in the extreme south of Brazil, which was previously identified as a hotspot of environmental pollution. In addition, an important part of Brazil's population suffers from socioeconomic vulnerability. Since there is no information on unfavorable gestational and neonatal outcomes associated with these problems, we conducted a cross-sectional study with 1950 mother-child binomials, aiming to evaluate the association between these outcomes and air pollution as well as socioeconomic, demographic and health variables in seven cities in the region. Of the total births, 11.6% were preterm and 9.5% of neonates had low birth weight (<2500 g). These conditions were also associated with skin color, previous abortions, birth type and prenatal care, as well as exposure to higher levels of coarse particulate matter (PM10) during the first trimester of pregnancy. Regarding air pollutants, although the daily limits for PM10 were exceeded on less than 5% of days, the annual average overtook the values proposed by WHO. Thus, we concluded that prematurity and low birth weight in this region are related to air pollution, and to socioeconomic variables and health care.

Acute toxicity and effects of Roundup Original® on pintado da Amazônia.

The toxicity of Roundup Original® (GLY), a glyphosate-based herbicide widely used in crops in Mato Grosso state, was determined in hybrid fish jundiara or pintado da Amazônia. The 96 h-LC50 of GLY was 13.57 mg L-1. Moreover, exposure to sublethal concentrations of GLY (0, 0.37, 0.75, 2.25, 4.5, 7.5 mg L-1) has not altered the survival rate (100% for all treatments). In fish liver, protein carbonyl (PC) levels as well as glutathione-S-transferase (GST) activity, reduced glutathione (GSH), and ascorbic acid (ASA) contents increased when compared to control group. Superoxide dismutase (SOD) activity was reduced and catalase (CAT) has not changed. PC content has grown in muscle and brain, and thiobarbituric acid-reactive species (TBARS) levels also increased in muscle, but in the brain, they remained unaltered. Acetylcholinesterase (AChE) activity reduced in muscle but increased in brain when compared to control group. Our results suggest that short-term exposure to GLY induced alterations in the oxidative stress biomarkers in fish and can be interfering with their survival in natural environment; besides, these findings may be considered of high ecotoxicological relevance.

Effects of glyphosate-based herbicide on pintado da Amazônia: Hematology, histological aspects, metabolic parameters and genotoxic potential.

Roundup Original® is an herbicide widely used in Mato Grosso's agriculture and it may contamine water bodies, being an unforeseen xenobiotic to aquatic organisms, particularly fish. This study investigated the effects on the hybrid fish jundiara (Leiarius marmoratus×Pseudoplatystoma reticulatum) of an environmentally relevant exposure to this herbicide. Glucose levels in liver, muscle and plasma decreased after exposure to 1.357mgL-1 of Roundup Original® (glyphosate nominal concentration), while glycogen levels reduced in liver and muscle for different times. Elevated cholesterol and triglycerides revealed an adaptive response. Protein and lactate levels also increased during the experiment, however no changes were observed for muscle lactate. Increment of the transaminases suggests damage to the liver cells. After 96hours of exposure, reductions in all hematological parameters were observed, whereas the micronucleus test findings showed genotoxic scenery. Histological analysis did not display pathological alterations of the hepatic tissue. The results obtained provide valuable data for noticing the effects of pollutants on non-target organisms.

Oxidative stress in the hybrid fish jundiara (Leiarius marmoratus × Pseudoplatystoma reticulatum) exposed to Roundup Original®.

The aim of this study was to investigate the effects of Roundup Original®, a glyphosate-based herbicide, against biochemical parameters including thiobarbituric acid-reactive substances (TBARS), protein carbonyl, enzymatic and nonenzymatic antioxidant responses and acetylcholinesterase (AChE) of jundiara fish (Leiarius marmoratus × Pseudoplatystoma reticulatum) at a sublethal concentration of 1.357 mg L-1. Fish exposed to the herbicide for different periods (6-96 h) showed a significant increase of both hepatic and muscular TBARS and protein carbonyl. Enzymatic antioxidant activity was decreased in the liver and brain after 48 h of exposure. Glutathione-S-tranferase (GST) had its levels raised in the brain and gills, probably as a toxicity event response. Non protein thiols (GSH) demonstrated a reduction after 6 and 24 h of exposure in the hepatic tissue, followed by an increase at 48 and 96 h in the same tissue. GSH brain levels, however, increased only after 96 h. AChE activity in muscle decreased for all the times tested (26.5, 45, 38 and 14% for 6, 24, 48 and 96 h respectively), but only at 96 h (34%) in the brain. We found that Roundup Original® is able to trigger important changes in the biochemical parameters tested, showing it can be a potential threat for the health and survival of fish in the environment.