Ecological Assessment of Storm Impacts

Data Collection

Abamectin

Basic Information

Synonym(s): Affirm; Agri-Mek; Avermectin; Avermectin B1; Avid; mixture of Avermectin B1a and Avermectin B1b; Zephyr
Formula: C₄₈H₇₂O₁₄
Molecular Weight: 873.1
Melting Point (°C): 150 - 155
Pronounciation: A-bah-meck-tin
Contaminant Type: Abamectin is an insecticide.
Additional Information: While the LC50 values are quite low, indicating a high level of toxicity to aquatic organisms, actual concentrations of abamectin in surface waters (fresh water) adjacent to treated areas are expected to be low. Application rates of 0.025 pounds of abamectin per acre (the highest recommended rate) should result in concentrations no higher than 26 parts per trillion in adjacent surface waters one day after the application. Rapid photodegradation and adsorption to sediments should produce even lower concentrations within days. The degradation products of abamectin are less toxic to aquatic organisms than abamectin itself. Because abamectin is nearly insoluble in water and has a strong tendency to bind to soil particles, it is therefore immobile in soil and unlikely to leach or contaminate groundwater. Compounds produced by the degradation of abamectin are also immobile and unlikely to contaminate groundwater. ^m

Solubility (in water)

• Solubility: 7.8E-09 g/100ml ^d
  

• Solubility: 5 mg/l ^l
  

Half-Life (in soil unless otherwise noted)

• t1/2: 1 weeks ^a
  Environment: Unshaded soil surface
  

• t1/2: 2-8 weeks ^a
  Environment: Underneath soil surface
  

• t1/2: <1 day ^c
  Environment: Aerobic soil, in the light
  Formulation: Avid 0.15 EC
  

• t1/2: ~20-47 days ^c
  Environment: Aerobic soil, in the dark
  Formulation: Avid 0.15 EC
  

• t1/2: 28 days ^l
  

• t1/2: 8.0-24.0 hours ^m
  Environment: Soil surface, subjected to rapid photodegradation
  

• t1/2: ~1 weeks ^m
  Environment: Soil surface, not shaded
  

• t1/2: 2.0-8.0 weeks ^m
  Environment: Dark, aerobic conditions
  

• t1/2: 20-47 days ^m
  Environment: Fine, sandy loam, clay and construction grade sand
  Formulation: avermectin B1a
  

Toxicity Effects

• Organism Type: Crustaceans ^m
  Common Name: Blue crab
  Scientific Name: Callinectes sapidus
  Toxicity: 153 µg/l
  Test: 96h LC50
  

• Organism Type: Crustaceans ^m
  Common Name: Daphnia
  Scientific Name: Daphnia magna
  Toxicity: 0.34 µg/l
  Test: 48h LC50
  

• Organism Type: Crustaceans ^c
  Common Name: Daphnia
  Scientific Name: Daphnia magna
  Toxicity: 0.34 µg/l
  Test: Acute LC50
  Formulation: Avid 0.15 EC
  

• Organism Type: Crustaceans ^m
  Common Name: Mysid shrimp
  Scientific Name: Mysidopsis bahia
  Toxicity: 0.022 µg/l
  Test: 96h LC50
  

• Organism Type: Crustaceans ^c
  Common Name: Mysid shrimp
  Scientific Name: Mysidopsis bahia
  Toxicity: 0.022 µg/l
  Test: Acute LC50
  Formulation: Avid 0.15 EC
  

• Organism Type: Crustaceans ^m
  Common Name: Pink shrimp
  Scientific Name: Panaeus duorarum
  Toxicity: 1.6 µg/l
  Test: 96h LC50
  

• Organism Type: Fish ^m
  Common Name: Sheepshead minnow
  Scientific Name: Cyprinodon variegatus
  Toxicity: 15 µg/l
  Test: 96h LC50
  

• Organism Type: Fish ^m
  Common Name: Carp
  Scientific Name: Cyprinus carpio
  Toxicity: 42 µg/l
  Test: 96h LC50
  

• Organism Type: Fish ^m
  Common Name: Channel catfish
  Scientific Name: Ictalurus punctatus
  Toxicity: 24 µg/l
  Test: 96h LC50
  

• Organism Type: Fish ^m
  Common Name: Bluegill
  Scientific Name: Lepomis macrochirus
  Toxicity: 9.6 µg/l
  Test: 96h LC50
  

• Organism Type: Fish ^c
  Common Name: Bluegill
  Scientific Name: Lepomis macrochirus
  Toxicity: 9.6 µg/l
  Test: Acute LC50
  Formulation: Avid 0.15 EC
  

• Organism Type: Fish ^m
  Common Name: Rainbow trout
  Scientific Name: Oncorhynchus mykiss
  Toxicity: 3.2 µg/l
  Test: 96h LC50
  

• Organism Type: Fish ^c
  Common Name: Rainbow trout
  Scientific Name: Oncorhynchus mykiss
  Toxicity: 3.6 µg/l
  Test: Acute LC50
  Formulation: Avid 0.15 EC
  

• Organism Type: Mammals ^g
  Common Name: Rat
  Scientific Name: Muridae (Family)
  Toxicity: 300 mg/kg
  Test: LD50
  

• Organism Type: Mammals ^m
  Common Name: Rat
  Scientific Name: Muridae (Family)
  Toxicity: 300 mg/kg
  Test: LD50
  Formulation: 1.8% w/v
  

• Organism Type: Mammals ^m
  Common Name: Rat
  Scientific Name: Muridae (Family)
  Toxicity: 11 mg/kg
  Test: LD50
  

• Organism Type: Molluscs ^m
  Common Name: Eastern oyster
  Scientific Name: Crassostrea virginica
  Toxicity: 430 µg/l
  Test: 96h LC50
  

Work Cited