Common Contaminants in Urban Watersheds - Urban Watersheds: Geology, Contamination, and Sustainable Development - page 242

According to ATSDR, DEHP is not toxic at the low levels usually present in the environ-
ment. In animals, DEHP has been found to damage the liver and kidneys and has affected
the ability to reproduce in some animal species.

7.6.2 Phenol

Phenol is a group of organic compounds with a hydroxyl group (-OH) attached to a carbon
atom in a benzene ring. Phenol compounds do occur naturally, and their presence in plant
foliage discourages herbivores from consuming the plant material (Fetzer 2000; McMurry
2009). Figure 7.11 is a diagram showing the basic structure of a phenol molecule. The sim-
plest phenol compound is carbolic acid (C 6 H 5 OH); also called phenol.
Phenol combined with formaldehyde forms a widely used polymer typically referred to
as a phenolic resin. Phenolic resins have a wide range of industrial and commercial appli-
cations including the following:

• Billiard balls
• Countertops
• Plastic
• Electrical components
• Coatings
• Composites
• Abrasives
• Adhesives
• Felt bonding
• Foundry applications
• Friction products
• Refactory products
• Rubber additives used as reinforcing agents

OH

Pentachlorophenol (PCP) is a phenol compound with the addition of chlo-
rine into its molecular structure (Figure 7.12). PCP has been used as an
herbicide, insecticide, fungicide, algaecide, and disinfectant. Other uses
include leather, masonry products, and wood preservatives; and utility
poles often employ PCP as a wood preservative (USEPA 2006a).
Bisphenol A or BPA is an organic phenolic compound with two phenol
functioning groups. Figure 7.13 shows the basic structure of BPA. BPA is a
very common compound and is used heavily in the production of plastic
products including bottles for drinking water and numerous other con-
sumer products (USDHH 2008). Some concern about health effects from
exposure to BPA have been expressed by the USDHH (2008), as type 7
plastics (polycarbonates) may leach PBA into the liquids they hold. In
2009, Canada banned the use of PBA in polycarbonates in baby bottles
(Carwile et al. 2009).
Table 7.9 lists the CAS registry number, structural formula, and carcino-
genicity rating for phenol, PCP, and BPA.

FIGURE 7.11
Basic structure
of phenol.

OH

Cl

Cl

Cl

Cl

Cl

FIGURE 7.12
Basic molecular
structure of pen-
tachlorophenol.