Risk evaluation of occupational exposure of southern Brazilian flower farmers to pesticides potentially leading to cholinesterase inhibition and metals exposure.

This work presents a frequency matched observational study comparing flower farmers exposed to pesticides and unexposed individuals as controls. All subjects were interviewed before plasma and urine collection. Manganese and Zinc were measured in theses samples by using dynamic reaction cell inductively coupled mass spectrometry. Cholinesterase activity was analyzed through spectrophotometry by using a modified version of the Ellman method. Seventy-eight percent of subjects reported occupational contact with pesticides, from which 37% reported exposure for over 9 years. Flower farms farmers had increased odds of having headache and irritability, respectively, by factors of 6.2 and 2.4 than the control subjects. While the odds of exposed subjects to have insomnia was smaller than control subjects by a factor of 0.34. Exposure to pesticides had a significant effect regarding the plasmatic plasma and urinary manganese levels and whole blood cholinesterase activity (p < 0.05). High levels of plasma and urinary manganese, as well as cholinesterase inhibition in whole blood, were evident in the flower farmers who participated in the study.

Anti-mycotoxigenic and antifungal activity of ginger, turmeric, thyme and rosemary essential oils in deoxynivalenol (DON) and zearalenone (ZEA) producing Fusarium graminearum.

This study aimed to evaluate the antimycotoxigenic effect of essential oils (EOs) obtained from four different aromatic plants on the production of deoxynivalenol (DON) and zearalenone (ZEA) by Fusarium graminearum. The EOs from ginger (GEO), turmeric (TEO), thyme (ThEO) and rosemary (REO) were obtained by hydrodistillation and identified by gas chromatography/mass spectrometry (GC/MS). The major compounds found were mostly monoterpenes and sesquiterpenes. The minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) were 11.25, 364, 366 and 11,580 µg mL-1 for ThEO, GEO, REO and TEO, respectively. The results evidenced that the assessed EOs inhibited DON and partially ZEA production by F. graminearum. ThEO and GEO were the EOs with most potent antimycotoxigenic action for DON and ZEA, respectively. These EOs have shown promising results in vitro regarding inhibition of mycotoxin production and might be used in the future as substitutes for synthetic fungicides.

Elemental plasma content and urinary excretion in vineyard farmers occupationally exposed to pesticides in southern Brazil.

This is a cross-sectional study with data and biological material collection from vineyard farmers in southern Brazil. An interview was carried out through a questionnaire developed according to the reference guide of the state government. Plasma and urine samples were screened for Aluminum, Chromium, Manganese, Copper, Nickel, Cobalt, Zinc, Arsenic, Selenium, Cadmium, Antimony, Barium, Mercury, Lead and Uranium, with a technique for fast determination of these elemental contents in biological material utilizing dynamic reaction cell inductively coupled mass spectrometry. Principal component analysis was used to identify associations between these elemental contents in biological samples and the information obtained from the interviews. The farmers showed some trace elements in plasma and urine at a higher concentration than unexposed populations from other studies. This study highlights recent findings of trace elements in biological material and their association with characteristics of pesticide use. In addition, it also contributes to the gap in the literature regarding trace elements content in plasma and urine of workers exposed to pesticides.

Efeitos antifúngico e antiaflatoxigênico de timol e carvacrol em Aspergillus flavus / Antifungal and antiaflatoxigenic activities of thymol and carvacrol against Aspergillus flavus

O objetivo deste estudo foi avaliar os efeitos do timol e carvacrol contra Aspergillus flavus e a produção de aflatoxinas. Foram determinadas a concentração inibitória mínima (CIM), o espectro fungitóxico e a atividade inibidora de micotoxinas pelo timol e carvacrol. Os resultados mostraram que timol e carvacrol exibiram ação fungicida de acordo com a CIM de 2500 e 30 µg mL-1, respectivamente. Tanto o timol quanto o carvacrol inibiram significativamente o crescimento de A. flavus (p<0,05) a partir de 600 e 15 µg mL-1, respectivamente. A biomassa fúngica, estimada pela determinação da concentração de ergosterol, foi significativamente reduzida (p <0,05) em 2500 µg mL-1 de timol e 250 µg mL-1 de carvacrol. O timol e o carvacrol exibiram efeitos antiaflatoxigênicos em 600 e 125 µg mL-1, respectivamente. O timol e o carvacrol exibiram atividade antifúngica, mas não exibiram alta atividade antiaflatoxigênica. Carvacrol e timol podem ser considerados como potentes compostos naturais antifúngicos contra A. flavus.

The aim of this study was to evaluate the effects of thymol and carvacrol upon production of aflatoxins by Aspergillus flavus and upon its growth. Minimal inhibitory concentration (MIC), fungitoxic spectrum and mycotoxin inhibition were assessed. Results showed thymol and carvacrol exhibited fungicidal action, as determined by MIC values of 2500 and 30 µg mL-1, respectively. Both thymol and carvacrol significantly inhibited growth of A. flavus (p<0.05) at concentrations of 600 and 15 µg mL-1, respectively. Fungal biomass, as estimated by determination of ergosterol concentration, was significantly reduced (p<0.05) at thymol concentrations of 2500 µg mL-1 and at carvacrol concentrations of 250 µg mL-1. Thymol and carvacrol exhibited antiaflatoxigenic effects at concentrations of 600 and 125 µg mL-1, respectively. While both thymol and carvacrol showed possessing antifungal activities, neither were highly antiaflatoxigenic. Carvacrol and thymol might be considered for use as potential antifungal natural compounds against A. flavus.

Antifungal and antiaflatoxigenic activity of rosemary essential oil (Rosmarinus officinalis L.) against Aspergillus flavus.

The increased risk to health by diverse pathologies, such as cancer, liver diseases, and endocrine alterations, caused by chemical residues in food, has led to the search for sustainable agricultural management alternatives, such as the use of essential oils for the development of natural and eco-friendly fungicides. The aim of this study was to evaluate the antifungal and antiaflatoxigenic activity of Rosmarinus officinalis L. essential oil (REO) against Aspergillus flavus Link. REO was obtained by hydrodistillation and its major components were identified as 1,8-cineole (eucalyptol, 52.2%), camphor (15.2%) and α-pinene (12.4%) by GC/MS and NMR. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were both 500 µg/mL. REO reduced the mycelial growth of A. flavus at a concentration of 250 µg/mL (15.3%). The results obtained from scanning electron microscopy (SEM) demonstrated a reduction in the size of conidiophores and in the thickness of hyphae in A. flavus caused by treatment with REO (250 µg/mL). The production of ergosterol and the biomass of mycelium were both reduced as the REO treatment concentration increased. The production of aflatoxins B1 and B2 was inhibited after treatment with 250 µg/mL REO, a concentration below the MIC/MFC, indicating that the antiaflatoxigenic effect of REO is independent of its antifungal effect and is likely due to its direct action upon toxin biosynthesis. The data demonstrated that REO may be used as an alternative to synthetic fungicides.

Antifungal activity and inhibition of aflatoxins production by Zingiber officinale Roscoe essential oil against Aspergillus flavus in stored maize grains / Atividade antifúngica e inibição da produção de aflatoxinas pelo óleo essencial de Zingiber officinale Roscoe contra Aspergillus flavus em grãos de milho armazenados

ABSTRACT: Essential oils are possible alternatives to the use of synthetic pesticides for control of fungal contamination. Ginger (Zingiber officinale) essential oil (GEO) is known for having antifungal and antiaflatoxigenic properties, but its use as a fumigant in situ has not been studied yet. The aim of this study was to evaluate GEO's effects upon Aspergillus flavus as a fumigant agent in stored maize grains. The main compounds reported in GEO were α-zingiberene (23.85%) and geranial (14.16%), characterized by gas chromatography-mass spectrometry and nuclear magnetic resonance. The GEO was used as a fumigant in irradiated maize grains in concentrations ranging from 5 to 50 µg/g and the resulting effects were compared to a synthetic antifungal agent (carbendazim and thiram), an antifungal traditionally used for seed treatment. The antifungal efficacy of GEO against A. flavus has been proven in a dose-dependent manner through in situ (maize grains) test. The GEO inhibited aflatoxin production at concentrations 25 and 50 µg/g and controlled fungal growth. Therefore, GEO can be used as an effective and non-toxic alternative to conventional treatments in stored maize grains for the natural control of A. flavus.

RESUMO: Os óleos essenciais são possíveis alternativas ao uso de praguicidas sintéticos no controle da contaminação por fungos. O óleo essencial de gengibre (Zingiber officinale - OEG) é conhecido por possuir propriedades antifúngicas e antiaflatoxigênicas, mas seu uso como fumigante in situ ainda não foi estudado. O objetivo deste estudo foi avaliar os efeitos do OEG sobre Aspergillus flavus como agente fumigante em grãos de milho armazenados. Os principais compostos encontrados no OEG foram α-zingibereno (23,85%) e geranial (14,16%), caracterizados por cromatografia gasosa acoplada a espectrometria de massas e ressonância magnética nuclear. O OEG foi utilizado como fumigante em grãos de milho irradiados em concentrações variando de 5 a 50 µg/g e os efeitos resultantes foram comparados a um agente antifúngico sintético (carbendazim e tiram), antifúngico tradicionalmente usado para o tratamento de sementes. A eficácia antifúngica do OEG contra A. flavus foi comprovada de maneira dependente da dose através do teste in situ (grãos de milho). O OEG inibiu a produção de aflatoxina nas concentrações 25 e 50 µg/g e controlou o crescimento de fungos. Portanto, o OEG pode ser usado como uma alternativa eficaz e não tóxica aos tratamentos convencionais em grãos de milho armazenados para o controle natural de A. flavus.

Occurrence and risk assessment of population exposed to deoxynivalenol in foods derived from wheat flour in Brazil.

Deoxynivalenol (DON) is the most important of the trichothecenes in terms of amounts and occurrence in wheat. This compound was shown to be associated with a glomerulonephropathy involving an increase of immunoglobulin A in humans. This study assessed the occurrence of DON in wheat flour and the exposure of Brazilian teenagers, adults and elderly to this mycotoxin due to intake of wheat flour-based products. DON extraction in wheat flour was carried out by solid phase extraction and the quantification was performed by ultra-high proficiency liquid chromatography with diode-array detection. A total of 77.9% of all samples were positive for DON, with concentrations ranging from 73.50 to 2794.63 µg kg-1. The intake was calculated for the average and 90th percentile of the contamination levels of DON in foods based-wheat for teenagers, adults and elderly in Brazil, and compared with the provisional maximum tolerable daily intakes (PMTDI). Females of all age groups were exposed to DON at higher levels when compared to males in regard of consumption of breads and pastas. Teenagers were the main consumers of foods derived from wheat flour, with maximum probable daily intakes of 1.28 and 1.20 µg kg-1 b.w. day-1 for females and males, respectively. This population is at an increased risk of exposure to DON due to consumption of wheat flour-based foods in Brazil.

Occurrence and exposure assessment to aflatoxins in peanuts commercialized in the northwest of Parana, Brazil / Ocorrência e avaliação da exposição as aflatoxinas em amendoim comercializado na região noroeste do Paraná, Brasil

ABSTRACT: Peanuts are a nutritious food consumed worldwide. Some species of the genus Aspergillus, producers of aflatoxins, colonize peanuts. Human exposure to aflatoxins occurs by ingesting contaminated foods. The objective of this paper was to assess the occurrence and dietary exposure of the population to aflatoxins in peanuts commercially available in Maringa, Brazil, from May 2013 to April 2017. A total of 104 peanut samples were evaluated by thin-layer chromatography and confirmed by derivatization with trifluoroacetic acid. The contamination rate detected was 24.0% in average concentration of 13.4µg/kg. Twenty positive samples (19.2%) exceeded the maximum level permitted in Brazil for the sum of four aflatoxins. Estimated probable daily intake was 1,28 µg/kg body weight/day, exceeding the Provisional Maximum Tolerable Daily Intake (0.001μg/kg body weight/day). According to the high levels of aflatoxins found in peanuts, there is need for further monitoring the presence of aflatoxins in peanuts in natura to reduce the levels of contamination.

RESUMO: O amendoim é um alimento nutritivo e muito consumido no mundo todo. Algumas espécies de fungos do gênero Aspergillus, produtores de aflatoxinas, colonizam o amendoim. A exposição humana as aflatoxinas ocorre por meio do consumo de alimentos contaminados. O objetivo deste estudo foi avaliar a ocorrência e exposição da população as aflatoxinas em amendoim comercializado no município de Maringá, Brasil, durante o período de maio de 2013 a abril de 2017. Foram avaliadas 104 amostras de amendoim por análise cromatográfica e confirmadas por derivação com ácido trifluoroacético. A frequência de contaminação foi de 24,0% em concentração média de 13,4µg/kg. Vinte amostras positivas (19,2%) apresentaram-se acima do limite máximo permitido no Brasil para a somatória das quatro aflatoxinas. A ingestão diária provável média encontrada foi de 1,28µg/kg peso corpóreo/dia, superando a ingestão diária máxima tolerável provisória (0,001µg/kg peso corpóreo/dia). De acordo com os elevados teores de aflatoxinas encontrados em amendoim, há necessidade de um maior monitoramento da presença de aflatoxinas em alimentos, tendo em vista a redução nos níveis de contaminação do amendoim in natura.

Exposure to heavy metals due to pesticide use by vineyard farmers.

OBJECTIVES: To statistically analyze serum heavy metal levels in biological samples obtained from vineyard workers from southern Brazil and check for heavy metal exposure due to pesticide use. METHODS: Serum samples were obtained from 54 farmers and 108 healthy unexposed individuals. Samples from the same farmers were obtained at three different time points over a 1-year period. Levels of lead, arsenic, nickel, zinc, manganese and copper were determined for each sample using dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS). All results were statistically analyzed using the nonparametric Kruskal-Wallis test (followed by Dunn's post hoc test). RESULTS: Results showed that serum heavy metal levels in farmers were twofold to fourfold higher than in controls. This difference was found for all heavy metals tested and was significant (p < 0.05). Serum metal levels among the farmers also correlated with the frequency of use of pesticides at a specific time of year, which varied according to seasonal conditions influencing the need for pesticide application. CONCLUSIONS: It can be concluded that in the vineyard region assessed, farmers were more susceptible to heavy metal exposure due to pesticide use.

Antifungal activity and inhibition of fumonisin production by Rosmarinus officinalis L. essential oil in Fusarium verticillioides (Sacc.) Nirenberg.

The chemical composition of Rosmarinus officinalis L. essential oil (REO) was analysed by gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy. The main compounds of the REO were 1.8 cineole (52.2%), camphor (15.2%) and α-pinene (12.4%). The mycelial growth of Fusarium verticillioides (Sacc.) Nirenberg was reduced significantly by 150 µg/mL of REO. Significant microscopic morphological changes were visualised, such as the rupture of the cell wall and the leakage of cytoplasm at 300 µg/mL of REO. At lower concentrations of REO, the effects on the production of ergosterol and the biomass of mycelium varied, as did the effects on the production of fumonisins, but at ≥300 µg/mL of REO, these processes were significantly inhibited, showing the effectiveness of the REO as an antifungal agent. The results suggested that the REO acts against F. verticillioides by disrupting the cell wall and causing the loss of cellular components, subsequently inhibiting the production of fumonisins and ergosterol.

Antifungal properties and inhibitory effects upon aflatoxin production of Thymus vulgaris L. by Aspergillus flavus Link.

The antifungal and antiaflatoxigenic properties of Thymus vulgaris essential oil (TEO) were evaluated upon Aspergillus flavus "in vitro". Suspension containing 10(6) of A. flavus were cultivated with TEO in concentrations ranging from 50 to 500 µg/mL. TEO reached minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) at 250 µg/mL. Inhibition of ergosterol biosynthesis was detected at a concentration of 100 µg/mL of TEO. Morphological evaluation performed by both light microscopy and scanning electron microscopy showed that antifungal activity of TEO could be detected starting at a concentration of 50 µg/mL and the fungicide effect at a concentration of 250 µg/mL. TEO completely inhibited production of both B1 and B2 aflatoxins (AFB1 and AFB2) at a concentration of 150 µg/mL. This way, fungal biomass development and aflatoxin production were dependent on TEO concentration. Therefore, TEO was capable of controlling the growth of A. flavus and its production of aflatoxins.

Pesticide use and cholinesterase inhibition in small-scale agricultural workers in southern Brazil

A controlled cross-sectional study of family growers of fruit and vegetables was conducted between October 2009 and October 2010 to characterize the use of pesticides, establish the socio-demographic profile, and analyze cholinesterase activity in small-scale agricultural workers in Southern Brazil. Data was collected for 173 workers and 179 controls. A structured questionnaire was applied collecting socio-demographic information and determining knowledge and work practices in relation to pesticide use. The benchmarks for total cholinesterase (ChEs) and butyrylcholinesterase (BuChE) were obtained from the average enzymatic activity of the occupationally unexposed group (control). The mean age of the exposed population was 40.0 ± 11.2 years. The symptoms differed significantly (p<0.05) between the exposed and unexposed populations. Forty (23.1%) workers showed symptoms associated with exposure to pesticides. The average value of enzymatic activity in the occupationally unexposed group for ChEs was 6.3 μmol/mL/min among males and 5.6 μmol/mL/min among females while for BuChE was 2.4 μmol/mL/min among males and 2.0 μmol/mL/min among females. Eight (4.6%) workers had high inhibition (>30%) of ChEs activity, whereas no workers showed high inhibition (>50%) of BuChE. Potential factors involved include gender, education, pesticide orientation, exposure, and hygiene measures.

Realizou-se um estudo transversal controlado, com hortifruticultores, durante o período de outubro de 2009 a outubro de 2010, a fim de caracterizar o uso de praguicidas, estabelecer o perfil sócio demográfico e analisar a atividade das colinesterases em trabalhadores rurais do sul do Brasil. Os dados foram obtidos de 173 trabalhadores e 179 controles. Um formulário estruturado foi aplicado obtendo informações sócio demográficas, conhecimento e práticas de trabalho relacionadas com o uso de praguicidas. Os valores de referência para colinesterases totais (ChEs) e butirilcolinesterase (BuChE) foram obtidos a partir da média da atividade enzimática do grupo controle. A idade média da população exposta foi de 40,0±11,2 anos. Os sinais/sintomas foram significativamente diferentes (p<0,05) entre a população exposta e não exposta. Quarenta trabalhadores (23,1%) apresentaram sinais/sintomas relacionados com a exposição aos praguicidas. O valor médio do grupo controle foi de 6,3 μmol/mL/min para o gênero masculino e 5,6 μmol/mL/min para o gênero feminino na ChEs; 2,4 μmol/mL/min para o gênero masculino e 2,0 μmol/mL/min para o gênero feminino na BuChE. Do total de trabalhadores (n=173), 08 (4,6%) apresentaram inibição elevada (>30%) das atividades das ChEs, e para BuChE nenhum trabalhador apresentou alta inibição (>50%). Dentre os fatores que poderiam estar envolvidos destacam-se o gênero, escolaridade, orientação para trabalhar com praguicidas, exposição e medidas de higiene.