Safe Herbicide Use

Environmental Consequences

Social Concerns

Max Williamson

Pesticide

• Any substance or mixture of substances used to kill, destroy ,repel, prevent or mitigate a pest.

Pesticide Names

Chemical name

Common name

Product name

There are three names associated with every pesticide.

Toxicity-Extent or degree to which a

chemical substance is poisonous to

humans/animals

Measures of Toxicity:The Median Lethal Dose

LD50

The amount (dose) of a chemical which produces death in 50% of a population of test animals to which it is administered by any of a variety of

methods

mg/kgNormally expressed as milligrams of substance per

kilogram of animal body weight

Acute Toxicity-Effects of

a Single Dose

Chronic Toxicity-Effects after

a Long Term Exposure

SUBCHRONIC/CHRONIC TESTING ( Long-term, low level exposures)

. Carcinogenicity (cancer)

. Reproduction/fertility

. Teratogenicity (birth defects)

. Delayed neurotoxicity (nervous

system)

. Dominant lethal (potential for genetic

change)

Relative Acute Toxicity:Insecticides

• Parathion 13.0 mg/kg

• Paraquat 95.0 mg/kg

• Carbaryl 270.0 mg.kg

• Malathion 370.0 mg/kg

Relative Acute Toxicity: Herbicides Garlon 4 1,581mg/kg Rainbow trout 0.74mg/L Bluegill 0.87mg/L Garlon 3A, Renovate 3 2,574mg/kg Rainbow trout 117mg/L Bluegill 148mg/L Roundup, Glypro Plus, etc. >5,000mg/kg Rainbow trout 8.2mg/L Bluegill 5.8mg/L Accord, Glypro, Rodeo, etc. >5,000mg/kg Rainbow trout >1,000mg/L Bluegill >1,000mg/L

Relative Toxicity:Are all substances toxic?

YES!

All are toxic to some quantifiable degree Sugar has an LD50 of 30,000 mg/kg Ethanol has an LD50 of only 13,700 mg/kg Even water has a recognized LD50 of slightly greater than 80,000 mg/kg

Primary Routes of Exposureto Pesticides

There are three primary routes by which organisms are exposed to pesticides

Oral

Inhalation

Dermal

Signal Words

The relative acute toxicity of a pesticide is reflected on the label in the form of a

“signal word”

The (toxicologically) appropriate signal word MUST appear on every pesticide label

The three possible signal words are:CAUTIONWARNINGDANGER

Formulator

Product name

EPA Registr #

Statement of Ingredients

Signal words & human health precautions

WPS Precautions

General information

Worker Protection Standard

EPA’s requirements for workers and handlers of pesticides

• Social Concerns

• Communications

Environmental Movement

r

Does your Herbicide have a Range and Pasture

Label?

Carefully kept records allow you to honestly answer questions without

relying on, sometimes selective, memory

Good communication requires that sufficient accurate information be given

Appropriate Tools of Communication

Accurate information

and

Appropriate language

Always try to know your audience

Don’t prejudice yourself

based on labels

There are almost always

surprises

Environmental scientist

Wildlife biologist

Senator-Physician

WHERE AND WHO

Often the most effective places for communication are the places where you

normally meet people -

the country store,

the grocery,

your church, ...

this means that technicians and temporaries are often doing the talking –

keep them up to speed on projects

Don’t promise things that you can’t deliver!

“I WANT A SPRAY THAT KILLS EVERYTHING BUT ISN’T DANGEROUS.”

DON’T !!!

What To Do:

• Be prepared; know your material

• Listen carefully• Keep your cool• Keep the level of discussion appropriate to the audience• and, everything else we have said in this talk• But, most of all, USE COMMON SENSE!

Maintain records of what you are doing and what is going on in your pesticide

program

Seek Experienced Assistance