Assessment of Mancozeb Exposure, Absorbed Dose, and Oxidative Damage in Greenhouse Farmers.

Mancozeb (MNZ) is a fungicide commonly employed in many countries worldwide. This study assesses MNZ absorption dynamics in 19 greenhouse farmers, specifically following dermal exposure, aiming to verify the efficacy of both preventive actions and protective equipment. For data collection, a multi-assessment approach was used, which included a survey to record study population features. MNZ exposure was assessed through the indirect measurement of ethylene thiourea (ETU), widely employed as an MNZ biomarker. The ETU concentration was measured with the patch method, detecting environmental ETU trapped in filter paper pads, applied both on skin and working clothes, during the 8 h work shift. Urine and serum end-of-shift samples were also collected to measure ETU concentrations and well-known oxidative stress biomarkers, respectively, namely reactive oxygen metabolites (ROMs), advanced oxidation protein products (AOPPs), and biological antioxidant potential (BAP). It was observed that levels of ETU absorbed and ETU excreted were positively correlated. Additionally, working clothes effectively protected workers from MNZ exposure. Moreover, following stratification of the samples based on the specific working duty (i.e., preparation and spreading of MNZ and manipulation of MNZ-treated seedlings), it was found that the spreading group had higher ETU-related risk, despite lower chronic exposure levels. AOPP and ROM serum levels were higher in MNZ-exposed subjects compared with non-exposed controls, whereas BAP levels were significantly lower. Such results support an increase in the oxidative stress upon 8 h MNZ exposure at work. In particular, AOPP levels demonstrated a potential predictive role, as suggested by the contingency analysis results. Overall, this study, although conducted in a small group, confirms that ETU detection in pads, as well as in urine, might enable assessment of the risk associated with MNZ exposure in greenhouse workers. Additionally, the measurement of circulating oxidative stress biomarkers might help to stratify exposed workers based on their sensitivity to MNZ. Pivotally, the combination of both ETU measurement and biological monitoring might represent a novel valuable combined approach for risk assessment in farmhouse workers exposed to pesticides. In the future, these observations will help to implement effective preventive strategies in the workplace for workers at higher risk, including greenhouse farmers who are exposed to pesticides daily, as well as to clarify the occupational exposure levels to ETU.

Toxicity characterization and environmental risk assessment of Mancozeb on the South American common toad Rhinella arenarum.

Agricultural activity, especially the increasing use of pesticides, is considered one of the main reasons for the decline of amphibian populations. Mancozeb (MCZ) is one of the most used fungicides worldwide, despite its ancient use and toxicity demonstrated in different taxa. However, there is limited information about the effects of MCZ in amphibians, which are keystones of riparian ecosystems. For species conservation purposes, it is essential to identify the most sensitive developmental period(s) of a given species to a xenobiotic. We evaluated the toxicity of a commercial fungicide of mancozeb, (80% active ingredient) on the early development of the common South American toad Rhinella arenarum (Anura, Bufonidae). Embryos from early blastula (S.4) and larvae from complete operculum (S.25) stages were exposed to a wide range of MCZ concentrations during acute, subchronic and chronic exposure (up to 504 h) periods. The toxicity profiles for lethal and sublethal effects were performed. At all exposure times, MCZ was more toxic to embryos, for instance, NOEC 504 h were 0.01 and 0.05 mg MCZ/L for embryos and larvae, respectively. Thus, embryo sensitivity was 5-fold higher than larvae. A Teratogenic Index of 14 indicated the significant teratogenic potential of this fungicide. Among sublethal effects, embryos exhibited a wide range of abnormalities with high incidence. The ecological risk assessment demonstrated that the estimated Risk Quotient value for Rhinella arenarum embryos at chronic exposure was higher than the Level of Concern value, which warns about the potential risk of MCZ for this native species.

Placing arbuscular mycorrhizal fungi on the risk assessment test battery of plant protection products (PPPs).

Arbuscular mycorrhizal fungi (AMF) are mutualistic symbionts considered a key group in soil systems involved in the provision of several ecosystem services. Recently they have been listed by EFSA as organisms to be included in the test battery for the risk assessment of plant protection product (PPPs). This study aimed to contribute to improve the ISO Protocol (ISO 10832: 2009) by assessing the feasibility of using other AMF species under different test conditions. Overall, results showed that AMF species Gigaspora albida and Rhizophagus clarus (selected out of five AMF species) are suitable to be used in spore germination tests using the ISO protocol (14 days incubation with sand or artificial soil as substrate) to test PPPs. However, several modifications to the protocol were made in order to accommodate the use of the tested isolates, namely the incubation temperature (28 °C instead of 24 °C) and the change of reference substance (boric acid instead of cadmium nitrate). The need for these changes, plus the results obtained with the three fungicides tested (chlorothalonil, mancozeb and metalaxyl-M) and comparisons made with literature on the relevance of the origin of AMF isolates in dictating the adequate test conditions, emphasize the importance of adjusting test conditions (AMF species/isolates and test temperature) when assessing effects for prospective risk assessment targeting different climatic zones. So, further studies should be conducted with different AMF species and isolates from different climatic regions, in order to better define which species/isolate and test conditions should be used to assess effects of a particular PPP targeting a given climatic zone.

Assessment of protective potential of Nigella sativa oil against carbendazim- and/or mancozeb-induced hematotoxicity, hepatotoxicity, and genotoxicity.

Nigella sativa oil (NSO) possesses antioxidant activity. However, its protective role against the hazards of fungicides has been poorly studied. Therefore, the present work aimed at determining the ameliorative potential of NSO against hepatotoxicity induced by carbendazim (CBZ) and/or mancozeb (MNZ) in female rats. In the present study, about 120 adult female Sprague-Dawley rats were randomly divided into eight equal groups. One group of animals was kept as a negative control (Gp. 1); groups 2, 3 and 4 orally received CBZ (200 mg/kg body wt) and/or MNZ (300 mg/kg body wt) daily for 2 weeks (positive groups). In order to assess the hepatoprotective potential of NSO, in comparison with NSO-treated rats (Gp. 5), groups 6, 7 and 8 were CBZ- and/or MNZ-exposed groups pre-treated orally with NSO (2 ml/kg body wt) daily for 2 weeks (prophylactic groups). All groups were kept further for 15 days without medications to observe the withdrawal effect. At the end of exposure and withdrawal periods, the body weight of all experimental rats was recorded and blood samples were collected for hematological, clinico-biochemical, and micronucleus assays. The animals were then sacrificed, and the liver and bone marrow were harvested for oxidative stress bioassay, chromosomal aberrations, DNA fragmentation, and histopathological examinations. The results suggested that pre-treatment with NSO remarkably diminished CBZ- and MNZ-induced macrocytic hypochromic anemia, leukocytosis, lymphocytosis, eosinophilia, and neutropenia. Besides, it also minimized the elevated liver enzymes, lipid peroxidation, micronucleus incidence, DNA damage, and chromosomal aberration frequency. Conversely, NSO significantly stimulated the CBZ- and/or MNZ-induced antioxidant system suppression. The NSO also normalized the hepatic structural architecture. As far as withdrawal effect is concerned, there was almost disappearance of the bad effects of these fungicides and the values were close to the normal range especially with the use of NSO. Ultimately, the results revealed that N. sativa oil is an effective hepatoprotective agent due to its genoprotective and free radical scavenging activities.

Vitamin E pretreatment prevents the immunotoxicity of dithiocarbamate pesticide mancozeb in vitro: A comparative age-related assessment in mice and chick.

Pesticides used for crop protection cause life-threatening diseases affecting the immune system of non-target organisms including birds and mammals. Functionality of immune system is age-dependent; early- as well as old-life stages are more susceptible to toxic exposures because of less competent immune system. Vitamins are so far known to reduce toxic effect of several pesticides and/or xenobiotics. The present in vitro study elucidated immunotoxicity of fungicide mancozeb through comparable stages of immune system maturation in mice (1, 3, and 12months) and chicks (4, 8, and 11weeks). In vitro splenocytes viability on exposure to mancozeb was quantitatively assessed by MTT assay and qualitatively by acridine orange and ethidium bromide (AO/EB) double fluorescence staining. Mancozeb exposure dose dependently (250, 500, 1000, 2500, 5000 and 10,000ng/ml) decreased the splenocytes viability. The in vitro preventive effect of Vitamin E has also been explored on toxicity induced by mancozeb. The increased susceptibility observed both in early and aged groups was due to less/decline competence of the immune system.

Assessment of the genotoxicity of propineb in mice bone marrow cells using micronucleus assay.

Propineb, a dithiocarbamate fungicide, is commonly used for the control of disease in a wide range of crops in agriculture. The genotoxic effects of commercial formulation of propineb in bone marrow cells of mice was investigated in vivo by micronucleus (MN) assay. The three different concentrations of propineb (12.5, 25 and 50 microg/ml; 0.01 ml per gram) were injected intraperitoneally (i.p.) to mice for 24 and 48 h. The results of the MN assay indicated that propineb induced a significant increase in frequency of micronucleated polychromatic erythrocytes (MNPCE) at 25 and 50 microg/ml concentrations for 24 h and at the highest (50 microg/ml) concentration for 48 h when compared with negative control. Also significant reduction for the polychromatic erythrocyte/normochromatic erythrocyte (PCE/NCE) ratio which is indicative for bone marrow cytotoxicity was observed at the same concentrations for 24 and 48 h. These results lead us to the conclusion that propineb may have genotoxic and cytotoxic potential due to induction in the frequency of MN and a reduction in PCE/NCE ratio in the bone marrow cells of mice.

Assessment of toxicological effects of mancozeb in male rats after chronic exposure.

Mancozeb, an ethylenebisdithiocarbamate fungicide was administered orally to male rats at doses 0, 500, 1000 and 1500 mg/kg/day for 90, 180 and 360 days produced dose dependent signs of poisoning, loss in body weight gain and mortality. However the signs of toxicity and mortality were more pronounced initially at 0-90 days as compared to 90-360 days of treatment period. A significant increase in the relative weight of liver and slight decrease in the kidney weight were observed in animals exposed to mancozeb (1000 and 1500 mg/kg/day) for 180 and 360 days associated with pathomorphological changes in liver, brain and kidney. Mancozeb has produced significant enzymatic changes in the activities of aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and acetylcholinesterase (AChE) throughout the period of study in a dose dependent manner. The alterations in the activity of enzymes associated with pathomorphological changes suggest that the chronic exposure of mancozeb produced significant toxicological effects in rats.