Mancozeb application

Chemical control. Under field test conditions, rust could be controlled using mancozeb (2.24 kg ha ) sprays applied to runoff at 7- to 10-day intervals starting when the plants were about 40 cm high and continuing until 2 weeks before harvest (McCarter and Kays, 1984). Rust control resulted in a 29% (13 ( ha ) increase in tuber yield. Unfortunately, mancozeb is not approved for use on Jerusalem artichokes in the U.S., nor are 8 to 11 or more spray applications realistic from an economic standpoint. The results do, however, underscore the need for the incorporation of resistance into commercial cultivars. 

Its persistence is very low in soil. One study recovered only 1.16% of mancozeb 7 days after application to silt loam soils, while the half-life was measured as only 3 days in fine sand. Lots of soil microorganisms readily break down mancozeb. 

Mancozeb has been shown to reduce the population of soil organisms, and in soil nitrification has been reported at concentrations ranging from normal to 10 times the normal field application rates. These changes have tended to be temporary and reversed within 3 months. 

Mancozeb is toxic to some plants such as marigold at normal field application rates. Some genetic effects were seen in onion cells exposed to mancozeb. 

For example, scoring an average 2 when no information exists or the element is obviously not applicable, we obtained notional values for mancozeb and metalaxyl used alone of 39 and 75 before extensive field use, and 39 and 96 after approx. 5 years use. This is roughly in line with the actual behaviour of these materials although the mancozeb score is near the top end of low risk, and might have caused some concern whereas in practice it has proved very low risk. 

Maneb and mancozeb. A man who was exposed via inhalation to 1.1 mg maneb/kg during a single application of the fungicide to a field was taken to the hospital with peripheral edema (de Carvalho et al. 

Maneb and mancozeb. Thyroid function tests in an adult male farmer who ingested unwashed vegetables in his garden after spraying 2 applications of maneb at a dose of 229 mg/kg/day were normal when taken 6 months after the exposure and subsequent to hemodialysis. No thyroid function tests were taken at the time of the maneb exposure (Koizumi et al. 1979). 

In a chronic carcinogenesis study in female Swiss mice, thrice weekly applications of technical grade mancozeb at a dose of 76 mg/kg active ingredient resulted in the increased mortality of treated subjects (Shukla et al. 1990). Eleven mice remained in a treatment group of 20 at 360 days of treatment fewer than 6 animals remained at 420 days of treatment. The deaths were reported to be related to the dermal toxicity caused by the mancozeb. 

A single dermal dose of 80 mg mancozeb/kg (administered in DMSO) increased the ornithine decarboxylase (ODC) activity in the skin of female Swiss mice (Gupta and Mehrotra 1992). Maximal enzyme activity was reached after a 5 hour application of the fungicide. The increase in ODC activity was dose-dependent, and... 

Most recent available data show, in 1989, that the combined annual use of maneb and mancozeb in the United States was 8,000-12,000 thousand pounds active ingredient (8-12 million pounds) (Bason and Colburn 1998), making maneb and mancozeb, collectively, the 16th most used pesticides. However, information regarding the quantity of specific pesticides produced or used is difficult to access because it is proprietary (Bason and Colburn 1998), and therefore, this is only an estimate. In 1989, forestry use of maneb and mancozeb, collectively, was less than 1,000 pounds active ingredient, and 1981 urban application was 32,000 pounds active ingredient. 

Mancozeb degrades rapidly in soil (Calumpang et al. 1993). Under field condifions, the half-lives of mancozeb, ethylenethiourea (ETU), and ethyleneurea (EU) in soil were 2.9, 2.5, and 4.8 days, respectively. Mancozeb is immobile in soil. Ethylene leached to a maximum of 8 cm of soil 14 days after application of mancozeb. 

Maneb or mancozeb. No studies were located that measured the concentration of these compounds after application of the compounds in the field on existing crops. All studies to date have involved localized application or laboratory measurements intended to report halfdives of the compounds in particular environments (Helling et al. 1974 Nash and Beall 1980 Rhodes 1977). None of the studies has reported increased manganese concentrations in either soil or sediment as a result of application of these fungicides. 

Occupational exposure to maneb and mancozeb can occur by the inhalation or dermal routes during the formulation and spray application of these pesticides (HSDB 1999). The general populahon is unlikely to be exposed to excess levels of pesticide residues on food, since crops analyzed for these compounds were found to have either non-detectable levels of the compounds or levels within allowable limits (Okumura et al. 1991) (see Section 5.4.4). 

Afsar et al. (1987) have developed a method to differentiate mancozeb from a mixture of maneb and zinc salts or from a mixture of maneb and zineb. Compounds are distinguished on the basis of color differences after treatment of the saturated solutions of fungicides in n-propanol-acetone mixture first with dithizone and then with monosodium dihydrogen phosphate. Stevenson (1972) presented a similar earlier method that distinguished maneb, zineb, mancozeb, and selected fungicidal mixtures by successive application of acid dithizone, sodium hydroxide, and acid dithizone to the spot. 

The purpose of this presentation Is to describe the results of field studies of dermal and Inhalation exposure of applicators and mixer-loaders to the fungicide mancozeb (DITHANE M-45 fungicide, 80Z active Ingredient wettable powder, a product of Rohm and Haas Company, Philadelphia, PA 19105, was used In these studies), a coordination product of zinc Ion and manganese ethyleneblsdlthlo-carbamate, and ethylene thiourea (ETU). The latter compound Is a decomposition product of all EBDC s (mancozeb, maneb, metlram, nabam and zlneb) and also Is produced from EBDC s as an artifact of the analytical procedure for ETU. 

Specific Spray Conditions. The field locations, equipment used and conditions for spraying potato fields with mancozeb by fixed-wing aircraft are presented in Tables II and III. Similar data for application of mancozeb by a ground alrblast sprayer (tomatoes) and by a compressed air sprayer (home yard) are given in Tables IV and V respectively. 

Table IV Application of Mancozeb by a Ground Air-Blast Sprayer...

Application of Mancozeb In a Home Yard With a Compressed Air Backpack Sprayer... 

The exposure of mixer-loaders and pilots during the airplane application of mancozeb to potato fields In Michigan, Minnesota and Oregon Is given In Tables VI, Vll and VIII. Mixer-loaders were exposed to mancozeb with forearms being most exposed (1125-9402 yg/body area). Pilots experienced very little exposure, but their hands did range from 58 to 1409 ig/body area. 

Table IX presents the exposure of persons Involved In the ground application of mancozeb by an alrblast sprayer to a tomato field In Ohio. Mixer-loaders again experienced exposure to mancozeb with forearms predominating (2856-3485 iig/body area). Tractor driver—applicators did not experience much exposure, but forearms did range from nondetectable to 1090 yg/body area. Home gardeners using a compressed air sprayer In a homeyard setting experienced little exposure to mancozeb (Table X), except for their ankle and thigh pads (nondetectable-4290 yg/body area).

The dermal and inhalation exposure of applicators and mixer-loaders to ethylenebisdlthlocarbamate and ethylenethlourea (ETU) was determined during field applications of mancozeb by airplanes In Michigan, Minnesota and Oregon, by alrblast sprayers In Ohio and by... 

Table VI. Exposure of Mixer-Loaders and Pilots to Mancozeb and ETU During the Application of Mancozeb... 

Table X Exposure of Mixer-Applicators to Mancozeb and Homeyard ETU During the Application of in Ohio Mancozeb to a ...

Brandes, Gordon A. "Applicator, Mixer/Loader Exposure Studies, Mancozeb (Dithane M-45)." Unpublished preliminary report for NCRPIAP Project Nos. 129 (132-NC-MN-F), 130 (133-NC-MI-P), 131 (134-NC-OH-F) and 132 (135-NC-OH-F) by H. L. Blssonette F. Tschirley and H.S. Potter J. Farley and C.C. Powell, respectively, and WRPIAP-Oregon Project by J.M. Witt and F.N. Dost. 1981. 

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