Common Contaminants in Urban Watersheds - Urban Watersheds: Geology, Contamination, and Sustainable Development - page 245

• Arsenic
• Barium
• Cadmium
• Chromium III
• Chromium VI
• Copper
• Lead
• Mercury
• Nickel
• Selenium
• Silver
• Zinc

Industrial watersheds are especially prone to heavy metal contamination. In an extensive
study of the Rouge River watershed in southeastern Michigan, Murray et al. (2004) dis-
covered elevated levels of barium, cadmium, chromium, copper, nickel, lead, and zinc in
surface soil. The occurrence of heavy metals in soil and in groundwater in urban areas is
discussed in greater detail in Chapter 9.
Table 7.12 lists the common uses for each of the heavy metals listed above. Table 7.13 lists
the CAS registry number and carcinogenicity ratings for each of the heavy metals.

TABLE 7.12
Common Uses for Each of f the Select Heavy Metals

Atomic
Number Heavy Metal Uses

Arsenic 33 Wood preservative, poison, insecticide, pigments, chemical weapons

Barium 56 Superconductors, pigments, fireworks, lubricants, optics

Cadmium 48 Batteries, plastic stabilizer, pigments, metal plating, coatings, alloys

Chromium III 24 Pigments, inks, glass, steel additive, dyes, leather tanning, refractory, alloys

Chromium VI 24 Metal plating, corrosion resistance additive, wood preservative

Copper 29 Wire, building products, piping, jewelry, electromagnetics, brass and other alloys

Lead 82 Batteries, paint, ceramics, firearms, industrial coolant, electrodes, solder,

construction materials, alloys, formerly a gasoline additive

Mercury 80 Electrical switches, thermometers, manometers, medical and dental applications,

cosmetics, mercury-vapor lamps, formerly used in hat making

Nickel 28 Batteries, steel additive, magnets, coins, alloys

Selenium 34 Photocells, electronics, semiconductors, steel additive, alloys, copier and printing

drums, glass manufacturing, pigments

Silver 47 Coins, electronics, circuit boards, alloys, mirrors, decorative items, jewelry,

photographic films, batteries

Zinc 30 Metal plating, rust inhibitor (galvanization), brass alloy, batteries, cathodic

protection, paint pigment, fire retardant, propellant, photocopying products,
medical applications

Source: Pradyot, P., Handbook of Inorganic Chemical Compounds , McGraw Hill, New York, 2003; Krebs, R.E., The

History and Use of Earth's Chemical Elements: A Reference Guide , Greenwood Publishing Group, Oxford,
U.K., 2006.