13
Historical and Current Uses of Pesticides
FIGURE 2.6
Synthetic herbicides include MCPA, 2,4-D, and 2,4,5-T.
FIGURE 2.7
TCDD is one of the most toxic chemicals known to humans.
FIGURE 2.8
Triazine herbicides include atrazine and simazine.
(Figure 2.7). TCDD is still seen in air samples collected near municipal dump
sites and particularly around incinerators (Shibamoto et al., 2007).
The triazine herbicides, atrazine and simazine, are heavily used on row
crops such as corn in the United States and elsewhere resulting in contamination of surface water and groundwater, and frequently are found in ambient
air samples (Figure 2.8).
Glyphosate or Roundup ™ (Figure 2.9) has become the dominant herbicide in the United States since its introduction by Monsanto in about 1980.
Glyphosate is a broad-spectrum systemic herbicide that leaves no signifcant toxic residues and breaks down in the environment to 2-amino3-(3-hydroxy-5-methyl-isoxazol-4-yl)propanoic acid (AMPA). It can often be
used without a permit and is of relatively low toxicity to people and wildlife. However, overuse can kill desirable vegetation such as milkweeds,
Senecio species (e.g., ragwort and groundsel), and other deep-rooted perennials that serve as refuge, food, or nectar sources for desirable species like
Historical and Current Uses of Pesticides
FIGURE 2.6
Synthetic herbicides include MCPA, 2,4-D, and 2,4,5-T.
FIGURE 2.7
TCDD is one of the most toxic chemicals known to humans.
FIGURE 2.8
Triazine herbicides include atrazine and simazine.
(Figure 2.7). TCDD is still seen in air samples collected near municipal dump
sites and particularly around incinerators (Shibamoto et al., 2007).
The triazine herbicides, atrazine and simazine, are heavily used on row
crops such as corn in the United States and elsewhere resulting in contamination of surface water and groundwater, and frequently are found in ambient
air samples (Figure 2.8).
Glyphosate or Roundup ™ (Figure 2.9) has become the dominant herbicide in the United States since its introduction by Monsanto in about 1980.
Glyphosate is a broad-spectrum systemic herbicide that leaves no signifcant toxic residues and breaks down in the environment to 2-amino3-(3-hydroxy-5-methyl-isoxazol-4-yl)propanoic acid (AMPA). It can often be
used without a permit and is of relatively low toxicity to people and wildlife. However, overuse can kill desirable vegetation such as milkweeds,
Senecio species (e.g., ragwort and groundsel), and other deep-rooted perennials that serve as refuge, food, or nectar sources for desirable species like