Monday, October 09, 2006
Aerial spray labels warn against drift
By Stella A. Estremera
DAVAO CITY -- Labels of Dithane, the brand name of the fungicide whose active ingredient is Mancozeb -- the one sprayed on banana plantations, explicitly warns against exposure of humans due to drift and drops, according to the official website of Dow AgroSciences.
Specimen labels of the chemicals from Dow AgroSciences that can be accessed through their website, www.dowagro.com, are in fact profuse with warnings.
Since directions for use are attached to all chemical products, then it is assumed that users, including banana plantations, know of these warnings.
Dow AgroSciences make different formulations under the Dithane brand, namely: Dithane 75DF Rainshield Specialty Fungicide, Dithane DF Rainshield Fungicide, Dithane F45 Rainshield Fungicide, Dithane M45 Fungicide, and two special formulations for banana plantation spraying -- Dithane 60OS and Dithane OS Special.
In all Dithane formulates under "Directions for use" it says: "Do not apply this product in a way that will contact workers or other persons, either directly or through drift."
Another warning states: "Do not apply when wind speed favors drift beyond the area intended for treatment."
It is also repeatedly warned that the product must be used according to its label.
In the various specimen labels, it also states, "During aerial application, human flaggers must be in enclosed cabs." Human flaggers are those who direct the spray planes from the ground.
In the technical profile of Dithane, www.dowagro.com/dithane.tech/index.htm, under "Labels and Safety Date Sheets, from where anyone can download prototype labels that warns against contact on humans, the safety sheets also warns of long-term effects.
Under Dithane M45 Fungicide, it notes that primary routes of exposure are inhalation, eye contact, skin contact.
Dithane M45 is the one used for fruits, including bananas, although the banana plantations here use a special formulation: the Dithane 60 OS, which unlike M45, which is a wettable powder, is an oil suspension concentrate especially made for aerial application on banana plantations.
Inhalation of the M45 dust can cause irritation of nose, throat and lungs, while direct contact can cause moderate irritation. Prolonged or repeated skin contact can cause possible skin irritation due to sensitization.
Also for Dithane M45, its Safety Sheet states: Dithane M45 Fungicide at high levels has caused hind leg paralysis in test animals and an increased incidence of retinal degeneration. It has caused thyroi tumors and birth defects in test animals, resulting from ethylenethiourea (ETU) formation. ETU, a trace contaminant and breakdown product of Dithane M45 Fungicide, primary affects the thyroid and liver.
It has also caused other endocrine and blood effects, tumors and birth defects in test animals.
The specimen label of M45 further warns against grazing livestock in treated areas, although for bananas, applications can be made up to the day of harvest.
Other excerpts from the product label and safety sheets include:
"This product contains mancozeb and ETU, chemicals known to the State of California to cause cancer. ETU is also known to the State of California to cause birth defects or other reproductive harm."
"Keep spectators away. Avoid breathing dust."
"CAUTION: Keep spills and cleaning runoff out of municipal sewers and open bodies of water."
"Toxocological information: Repeated exposure to mancozeb at high doses affects the thyroid, liver, and nervous systems in laboratory animals. The thyroid and liver effects are due to its metabolism in small amounts to ETU, which interferes with thyroid hormone synthesis and induces stress-related liver growth.
These effects are reversible when exposure is brief or intermittent, but prolonged exposures can produce secondary changes, including anemia and thyroid, pituitary and liver tumors in rodents. In common with other ethylenebisdithocarbanates, hind leg paralysis and related neurotoxic effects including retinal atrophy were noted at high doses."
No observed adverse effect level (NOAEL) is at 125 ppm or 5 mg/kg bw/day. In studies with mancozeb, a two-year feeding study in rats indicated thyroid effects and tumors and an increased incidence of retinopathy at a dietary concentration of 750 ppm, the Dithane safety sheet stated.
In the debate whether to ban or not aerial spraying of chemicals on bananas, Dr. Dr. Anacleto Pedrosa, PBGEA technical committee director, has described their chemicals as the least harmful among pesticides.
In a diagram supplied by PBGEA, it showed that Dithane has an active ingredient called Mancozeb. Dosage rate of the fungicide in liters per hectare is only 2.5 with its active ingredient having only 1.5 liters per hectare dosage rate.
That is why, Pedrosa said, they are certain that the chemicals sprayed are not "death threatening" to humans as what some sectors would like to project.
He said that mere washing off after accidental exposure would remove the chemical.
This is seconded in the Dithane labels, which advises that if formulation gets in contact with skin, the affected person must immediately take off the contaminated clothing and rinse skin immediately with plenty of water for 15-20 minutes. (Sun.Star Davao/Sunnex)
(October 9, 2006 issue)
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