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.

In vitro and in vivo impairment of embryo implantation by commonly used fungicide Mancozeb.

The fungicide Mancozeb is an endocrine-disrupting chemical and the mode of action of Mancozeb on embryo implantation is largely unknown. Mancozeb (1 and 3 µg/ml) significantly reduced Jeg-3 trophoblastic spheroids attachment to endometrial epithelial Ishikawa cells. Mancozeb treatment from gestation day (GD) 1 to GD8 or from GD4 to GD8 significantly lowered the number of implantation sites with higher incidence of morphological abnormalities in the reproductive tissues. However, these were not seen in the treatment from GD1 to GD4. Mancozeb at 30 mg/kg BW/d did not alter the expression of p53, COX-2, or PGFS transcripts in the uterus, but down-regulated the PGES transcript and protein. Mancozeb treatment in human endometrial stromal cells did not alter the decidualization response, but the morphological transformation was impaired. Taken together, exposure to Mancozeb affected embryo implantation probably through the modulation of decidualization and to delineate the exact mode of action needs further investigations.

Vitamins E and C prevent apoptosis of testicular and ovarian tissues following mancozeb exposure in the first-generation mouse pups.

The aim of this study was to evaluate the role of apoptosis in the first-generation pups' testicular and ovarian tissue changes following mancozeb (MNZ) administration during intrauterine and lactating periods and also the preventive effect of the co-administration of vitamins E and C on these changes. Naval Medical Research Institute (NMRI) pregnant mice were randomly divided into six groups: control, vehicle, MNZ, vitamin E plus MNZ, vitamin C plus MNZ and vitamins E and C plus MNZ. Administered doses of MNZ and vitamins E and C were 500, 200 and 100 mg/kg of body weight, respectively. These agents were administered to the animals by oral gavage every 2 days. Vitamin treatment was carried out 30 min prior to MNZ administration. Treatment was started on the second day of gestation and continued until weaning. Separated testes and ovaries of animals were prepared for apoptosis detection by terminal deoxynucleotidyl transferase end-labeling (TUNEL) staining. The percentage of TUNEL-positive cells was reported using the 4,6-diamidino-2-phenylindole method. As compared to the control and vehicle groups, MNZ induced a significant increase ( p < 0.001) in the number of TUNEL-positive cells. The administration of both vitamins E and C alone and together significantly ( p < 0.001) prevented the apoptotic impacts of MNZ. The preventive effect of the co-administration of these vitamins on the ovary was greater compared to the single administration of vitamins E ( p < 0.001) or C ( p < 0.001). Meanwhile, the results revealed the stronger preventive effect of vitamin C as compared to E on testicular tissue ( p < 0.05). The apoptotic impact of MNZ exposure during intrauterine and lactating periods on first-generation testicular and ovarian tissues was significant. The co-administration of vitamins E and C could prevent MNZ-induced testicular and ovarian changes.

Exposure of Drosophila melanogaster to Mancozeb Induces Oxidative Damage and Modulates Nrf2 and HSP70/83.

Mancozeb (MZ), a manganese- and zinc-containing ethylene-bis-dithiocarbamate, is a broad-spectrum fungicide. Harmful effects of this fungicide have been reported in nontarget organisms via a not fully understood mechanism. Drosophila melanogaster has provided remarkable contributions for toxicological studies. This work was aimed at evaluating the biochemical targets and implication of oxidative stress in MZ-mediated toxicity in drosophilas. Exposure of flies for fifteen days to MZ at 5 and 10 mg/mL through the diet impaired locomotor performance and induced fly mortality. In parallel, it caused lipid peroxidation and reactive oxygen species (ROS) formation and Mn overload. MZ inhibited superoxide dismutase and inducted catalase and glutathione S-transferase activities. Nitric oxide and reduced glutathione levels were significantly decreased by MZ. Heat shock proteins (HSP70 and HSP83) and Nrf2 mRNA levels were significantly augmented in MZ-exposed flies. Our study reinforced the use of Drosophila melanogaster as a reliable model for the study of biochemical targets of pesticides, and based on our data, MZ induced oxidative damage and Mn accumulation in a concentration-dependent manner. An adaptative cellular state was inducted by the lower concentration of pesticide, possibly contributing to the slighter damage observed.

Aerial application of mancozeb and urinary ethylene thiourea (ETU) concentrations among pregnant women in Costa Rica: the Infants' Environmental Health Study (ISA).

BACKGROUND: Mancozeb and its main metabolite ethylene thiourea (ETU) may alter thyroid function; thyroid hormones are essential for fetal brain development. In Costa Rica, mancozeb is aerially sprayed at large-scale banana plantations on a weekly basis. OBJECTIVES: Our goals were to evaluate urinary ETU concentrations in pregnant women living near large-scale banana plantations, compare their estimated daily intake (EDI) with established reference doses (RfDs), and identify factors that predict their urinary ETU concentrations. METHODS: We enrolled 451 pregnant women from Matina County, Costa Rica, which has large-scale banana production. We visited 445 women up to three times during pregnancy to obtain urine samples (n = 872) and information on factors that possibly influence exposure. We determined urinary ETU concentrations using liquid chromatography mass spectrometry. RESULTS: Pregnant women's median urinary ETU concentrations were more than five times higher than those reported for other general populations. Seventy-two percent of the women had EDIs above the RfD. Women who lived closest (1st quartile, < 48 m) to banana plantations on average had a 45% (95% CI: 23, 72%) higher urinary ETU compared with women who lived farthest away (4th quartile, ≥ 565 m). Compared with the other women, ETU was also higher in women who washed agricultural work clothes on the day before sampling (11%; 95% CI: 4.9, 17%), women who worked in agriculture during pregnancy (19%; 95% CI: 9.3, 29%), and immigrant women (6.2%; 95% CI: 1.0, 13%). CONCLUSIONS: The pregnant women's urinary ETU concentrations are of concern, and the principal source of exposure is likely to be aerial spraying of mancozeb. The factors predicting ETU provide insight into possibilities for exposure reduction.

Mechanism of thermal decomposition of a pesticide for safety concerns: case of Mancozeb.

Thermal decomposition under both air and inert atmospheres of a commercial Mancozeb product was investigated through thermogravimetric analysis and laboratory scale thermal treatment from 20°C to 950°C, with analysis of gaseous and solid products. The aim of this study is the understanding of the thermal degradation mechanisms of a pesticide under different atmospheres and the chemical identification of the solid and gaseous pollutants which can be emitted during warehouse fires and which can constitute a threat for health and environment. Pyrolysis of Mancozeb takes place between 20°C and 950°C and lead essentially to CS(2) and H(2)S emissions with formation at 950°C of MnS and ZnS. Thermal oxidation of Mancozeb under air occurs between 150°C and 950°C with formation of CO, CO(2) and sulphur gases (CS(2) and SO(2)). The first step (155-226°C) is the loss of CS(2) and the formation of ethylene thiourea, ZnS and MnS. The metallic sulphides are oxidized in ZnO and MnSO(4) between 226°C and 650°C (steps 2 and 3). MnSO(4) is then oxidized in Mn(3)O(4) during the last step (step 4) between 650°C and 950°C. At 950°C, carbon recovery is close to 95%. Sulphur recovery is close to 98% with an equal partition between SO(2) and CS(2).

Headache caused by handling the pesticide Antracol Combi WP 76: a case report.

We report on headache caused by the pesticide Antracol Combi WP 76. A headache caused by handling of pesticides should be distinguishable from migraine and headaches from other causes. This 29-year-old woman, who handled pesticides, presented with very strong headache with nausea and vomiting. Poisoning by this pesticide cannot be proven toxicologically, and there is no antidote. Following isolation from the pesticide and abundant hydration, the pain gradually decreased. History, clinical signs and neuroradiological examinations excluded other possible causes of the headache. In treatment of patients in rural areas, attention should also be paid to the pesticide Antracol Combi WP 76 as a possible cause of headaches.

Changes in serum markers indicative of health effects in vineyard workers following exposure to the fungicide mancozeb: an Italian study.

The aim of this study was to investigate the health effects induced by exposure to the fungicide mancozeb in Italian vineyard workers. Ninety-three Italian subjects entered the study - 48 vine-growers intermittently exposed to mancozeb and 45 healthy controls. The subjects were investigated three times: before the seasonal application of pesticides (T0), 30 days after the beginning of the application period (T30), and 45 days after T0 (T45). At T0 the comparison between agricultural workers and controls showed a higher prevalence of cold or flu symptoms, a statistically significant lower percentage of monocytes, higher absolute count of T lymphocytes, CD4 and natural killer cells, and lower plasma levels of IgA and IgM in workers. Such differences were not confirmed at T30 and T45. In fact at T30 in exposed workers, besides a significant increase of urinary ethylenethiourea, confirming mancozeb exposure, T lymphocytes, CD4 and natural killer cells, IgA and IgM returned to values comparable to those observed in controls. Moreover, no other differences in clinical signs, haematological, and immune parameters, such as the immune functional capability evaluated as a response to hepatitis B vaccination, was observed. Altogether the differences between exposed and controls were not consistently correlated to any clinical impairment and suggest that the seasonal application of mancozeb does not pose a significant health risk to exposed subjects.

Results from two years of field studies to determine Mancozeb based spray programmes with minimal impact on predatory mites in European vine cultivation.

Mancozeb is a dithiocarbamate fungicide with contact activity against a wide range of economically important fungal diseases. Its multi-site mode of action means that to date there have been no recorded incidences of resistance developing despite many years of use on high risk diseases. One such disease, Grape downy mildew (Plasmopara viticola) has developed resistance to a wide range of important oomycete specific fungicides following their introduction onto the market. The role of Mancozeb either as a mixing or alternation partner in helping to manage these resistance situations remains critically important. Historical use patterns for mancozeb in tree and vine crops involved many applications of product at high use rates. Although this gave excellent disease control, a negative impact on predatory mites was often reported by researchers. This has lead to the development of mancozeb spray programmes in vines and other crops with a much reduced impact on predatory mites. A range of field studies was conducted over two years in France, Germany, Italy, Portugal and Spain where 2, 3 or 4 applications of mancozeb containing products were made per season at different spray timings. In this paper findings from field studies over two years in five different vine growing regions in Europe indicated that two to four applications of mancozeb at 1.6 kg a.i./ha as part of a spray programme caused minimal impact on naturally occurring populations of predatory mites which in turn was compatible with Integrated Pest Management programmes and the conservation of predatory mites.

Effects of prenatal paraquat and mancozeb exposure on amino acid synaptic transmission in developing mouse cerebellar cortex.

The goal of this study was to analyze the effects of prenatal exposure to the pesticides paraquat (PQ) and mancozeb (MZ) on the development of synaptic transmission in mouse cerebellar cortex. Pregnant NMRI mice were treated with either saline, 10 mg/kg PQ, 30 mg/kg MZ or the combination of PQ + MZ, between gestational days 12 (E12) and E20. Variation in the levels of amino acid neurotransmitters was determined by HPLC, between postnatal day 1 (P1) and P30. Motor coordination was assessed by locomotor activity evaluation of control and experimental pups at P14, P21 and P30. Significant reductions in the levels of excitatory neurotransmitters, aspartate and glutamate, were observed in PQ-, MZ- or combined PQ + MZ-exposed pups, with respect to control, during peak periods of excitatory innervation of Purkinje cells: between P2-P5 and P11-P15. However, at P30, lower aspartate contents, in contrast with increased glutamate levels, were detected in all experimental groups. During the first two postnatal weeks, delays in GABA and glycine ontogenesis were observed in PQ- and PQ + MZ-exposed pups, whereas notable decrements in GABA and glycine levels were seen in PQ + MZ-exposed animals. Decreased taurine contents were detected at P3 and P11 in PQ- and PQ + MZ-exposed mice. Pups in different experimental groups all showed hyperactivity at P14 and then exhibited reduced locomotor activity at P30. Taken together, our results indicate that prenatal exposure to either PQ or MZ or the combination of both could alter the chronology and magnitude of synaptic transmission in developing mouse cerebellar cortex.

Lymphohematopoietic cancers in the United Farm Workers of America (UFW), 1988-2001.

OBJECTIVE: Agricultural risk factors for lymphohematopoietic cancers (LHC) in Hispanic farm workers in California were examined in a nested case-control study embedded in a cohort of 139,000 ever members of a farm worker labor union in California. METHODS: Crop and pesticide exposures were estimated by linking county/month and crop specific job history information from union records with California Department of Pesticide Regulation pesticide use reports during the 20-year period prior to cancer diagnosis. RESULTS: A total of 131 LHC diagnosed in California between 1988 and 2001 were included in the analysis. Analyses were conducted by gender and subtype of non-Hodgkins lymphoma (nodal, extra nodal) and by leukemia histology (lymphocytic, granulocytic). Odds ratios were calculated by stratification and by unconditional logistic regression. Risk for all LHC was elevated in workers cultivating vegetables (OR = 1.67, 95% CI = 1.12-2.48). Risk of leukemia was associated with exposure to the pesticides mancozeb (OR = 2.35, 95% CI = 1.12-4.95) and toxaphene (OR = 2.20, 95% CI = 1.04-4.65) while NHL risk was increased in association with 2,4-D (OR = 3.80, 95% CI=1.85-7.81). Risk of leukemia was particularly elevated among female workers and for granulocytic versus lymphocytic leukemia for several chemicals. No associations were noted for multiple myeloma. CONCLUSIONS: California farm workers employed where mancozeb and toxaphene were used had an increased risk of leukemia compared to farm workers employed elsewhere. Employment in farms using 2,4-D was associated with an increased risk of NHL.

Field studies to determine mancozeb based spray programmes with minimal impact on predatory mites in European vine cultivation.

Mancozeb is an ethylene bisdithiocarbamate (EBDC) fungicide with contact activity against a wide range of economically important fungal diseases. Its multi-site mode of action means that to date there have been no recorded incidences of resistance developing despite many years of use on high risk diseases. One such disease, Grape downy mildew (Plasmopara viticola) has developed resistance to a number of important oomycete specific fungicides following their introduction onto the market. The role of Mancozeb either as a mixing or alternation partner in helping to manage these resistance situations remains critically important. Historical use patterns for mancozeb in tree and vine crops involved many applications of product at high use rates. Although this gave excellent disease control, a negative impact on predatory mites has been reported by researchers. This has lead to the development of mancozeb spray programmes in vines and other crops with a much reduced impact on predatory mites. A range of field studies was conducted in France, Germany, Italy, Portugal and Spain where either 2 or 4 applications of mancozeb containing products were made per season at different spray timings. These trials covered the representative range of uses, agronomic practices, mite species and geographical locations in Europe. In this paper findings from ten field studies in five different vine growing regions in Europe indicated that two to four applications of mancozeb at 1.6 kg a.i./ha as part of a spray programme caused minimal impact on naturally occurring populations of predatory mites which in turn was compatible with Integrated Pest Management programmes and the conservation of predatory mites.

Anti-implantation effect of a carbamate fungicide mancozeb in albino mice.

Mancozeb, an organocarbamate fungicide, was administered to examine the effect on implantation at doses of 18, 24, 30 and 36 mg/kg body weight/d to normal virgin swiss albino mice for 8 days to pregnant mice. The vaginal smear and body weight of the mice were recorded daily and mice were sacrificed on 9th day of pregnancy. There was a complete inhibition of implantation in 36 mg mancozeb treated mice with 100% pre-implantation loss. There was a partial inhibition of implantation in 24 and 30 mg mancozeb treated mice with 53.44 and 90.16% pre-implantation loss respectively. However, implantation was not affected in 18 mg mancozeb treated mice with 4.92% pre-implantation loss when compared to oil treated controls. To study the temporal effect, the effective dose of 36 mg/kg body weight/d mancozeb was administered orally for 3 and 5 days and on day 3 only. There was a complete inhibition of implantation in 5 days treated mice with 100% pre-implantation loss and partial inhibition of implantation of 3 days treated mice with 75% pre-implantation loss. However, implantation was not affected in mice treated on day 3 only with 1.63% pre-implantation loss when compared to control mice. There was a significant decrease in the diestrus phase with the result there was a concomitant increase in the estrus phase and there was a significant decrease in the uterus weight with 24, 30 and 36 mg and for 3 and 5 days with 36 mg mancozeb treatment. Inhibition of implantation by mancozeb may be due to hormonal imbalance or its toxic effects.

Induction of gonadal toxicity to female rats after chronic exposure to mancozeb.

Mancozeb, a fungicide of ethylenebisdithiocarbamate group was orally administered at doses of 500, 600, 700 and 800 mg/kg body weight/day to normal virgin rats of Wistar strain for 30 days. The vaginal smear and body weight of the rats were recorded daily and rats were sacrificed on 31st day. Estrous cycle was effected by showing a significant decrease in the number of estrous cycle, duration of proestrus, estrus and metestrus with concomitant significant increase in the duration of diestrus in all the mancozeb treated groups when compared with controls. There were a significant decrease in the number of healthy follicles and a significant increase in the number of atretic follicles in all the mancozeb treated groups when compared with controls. The histologic observation of the ovary revealed the presence of less number of corpora lutea and the size of the ovary was also reduced in high doses of mancozeb treated rats. There was a significant increase in the thyroid weight in all the mancozeb treated rats except in 500 mg/kg/d. In rats treated with 500 mg/kg/d showed a significant increase in the level of total lipids in the liver. In rats treated with 600 mg/kg/d mancozeb showed a significant decrease in the levels of glycogen and total lipids in the uterus and total lipids in the liver. In rats treated with 700 mg/kg/d showed a significant decrease in the levels of protein in ovary, glycogen, total lipids, phospholipids and neutral lipids in the uterus and a significant increase in the levels of phospholipids, neutral lipids in the ovary and total lipids, phospholipids and neutral lipids in the liver. In rats treated with 800 mg/kg/d showed a significant decrease in the levels of protein and glycogen in the ovary and protein, glycogen, total lipids, phospholipids and neutral lipids in the uterus and a significant increase in the levels of total lipids, phospholipids and neutral lipids in the ovary and liver when compared with controls. These observed effect of mancozeb on the estrous cycle, follicles and biochemical constituents may be due to imbalance in the hormone or toxic effect.

Effects of fungicides on thyroid function, metabolism, and thermoregulation in cotton rats.

Among the myriad of recent studies on endocrine-disrupting chemicals, relatively few involve thyroid disruption, and most of these address exposure/disruption during embryonic life. Of those involving adult vertebrates, the endpoints examined are thyroid measurements. Even though thyroid disruption could potentially interfere with energy metabolism and thermoregulation such that over-winter survival might be compromised, the possible energetic consequences of these thyroid perturbations have not been investigated. We assessed thyroid function and measured resting metabolic rates of cotton rats chronically exposed to the fungicides vinclozolin or mancozeb. In addition, we measured norepinephrine-induced nonshivering thermogenesis and cold-induced thermogenesis and then cold-acclimated the mancozeb animals. Although thyroid hormone concentrations generally decreased, this was compensated for by an increase in thyroxine turnover (vinclozolin study only) such that thyroxine utilization rate was not different. In addition, there was no difference between the treated and control animals in any of the metabolic parameters measured. It is concluded that wild rodents exposed to these compounds are not energetically compromised.

The effectiveness of ecologically acceptable ways of protection of field-grown tomato (Lycopersicon lycopersicum (L.) Karsten) from tomato late blight (Phytophthora infestans (Mont.) de Bary) in extreme weather conditions.

During the extremely wet vegetation season in 1999 the efficiency of protection of two cultivars of field grown tomato (Lycopersicon lycopersicum (L.) Karsten), 'Pick Rite' and 'GO 101', against tomato late blight (Phytophthora infestans (Mont.) de Bary) using three ecologically acceptable growing techniques and agrochemical measures (growing on black plastic mulch with no fungicides used, spraying with Dithane M-45 (mancozeb), spraying with Cuprablau-Z (Cu-hydroxide) and control) have been studied. It was found out that under such extreme weather conditions none of these measures can ensure an adequate protection of tomato. The highest yield of healthy fruits (0.30 kg per plant) was obtained after a threefold spraying with Dithane M-45 (mancozeb), the highest percentage of non infected fruits (38.1%) after a twofold spraying with Cuprablau-Z (Cu-hydroxide). The black plastic mulch, used with the intention to reduce the plant contact with the potential inoculum in the soil proved to be ineffective.