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HANDBOOK OF ECOTOXICOLOGY

Naphthalene

Figurę 14.2 Examples of PAH compounds without attached alkyl groups.¹⁶ Hydrogen atoms bonded to carbon atoms are omitted.

14.3 SOURCES

14.3.1 Petroleum

During the early 1970s about 35% of the petroleum hydrocarbons in the marinę environment came from spills and discharges related to marinę transportation; the remainder came from offshore oil and gas production, industrial and municipal discharges, stormwater discharges, river runoff, atmospheric deposition, and natural seeps⁹-¹⁰ (Figurę 14.4). Transportation spills and discharges probably accounted for less than 35% of the total oil discharged onto land and freshwater environ-ments.¹⁰ Estimates for the late 1970s indicated that about 45% of the petroleum hydrocarbons in the marinę environment came from spills and discharges related to marinę transportation." In heavily used urban estuaries, the contribution of transportation spills and discharges to total petroleum hydrocarbon input can be 10% or less.¹²-¹³ By contrast, the largest source of petroleum in Coastal or inland areas removed from urban or industrial centers is petroleum transportation. In the 1980s and 1990s, war, terrorism, vandalism, and theft became additional, and sometimes major, causes of petroleum discharges into water and land environments.¹⁴¹⁵