It is important to stop incinerating our wastes not only because incinerators contaminate local air, but also because they are destroying the productivity of the oceans and other large water-bodies such as Chesapeake Bay, Puget Sound, and the Great Lakes.

You might think the oceans are so large that puny humans could not contaminate them to any significant extent. But you would be wrong.

The uppermost surface of the ocean forms a peculiarly important and, until recently, poorly understood, ecosystem. Scientists refer to it as the "sea-surface microlayer." The sea-surface microlayer is the top 50 micrometers of the ocean--a layer half the thickness of the period at the end of this sentence, yet critically important to life in the oceans or, for that matter, in any large body of water such as the Great Lakes, the Gulf of Mexico, Puget Sound, or Chesapeake Bay. The microlayer is composed of bacteria, yeasts, and molds in concentrations as much as 10,000 times greater than in the water below. Microscopic plants and animals also concentrate in the microlayer, creating an invisible organic film on the surface of the water, rich in lipids (fats and oils) and fatty acids.

The sea-surface microlayer is a highly productive habitat for a broad array of living things.[2] Numerous species of fish, including cod, sole, menhaden, hake, anchovy, mullet, flying fish, greeling, saury, rockfish, bluefish, mackerel, halibut and many others have surface-dwelling egg or larval stages. In estuarine, coastal, and shelf areas, blue crab, Dungeness crab, and lobster larvae also concentrate in the surface film during mid-day, drawn there by the abundance of sunlight. Because of its importance as a nursery for fish eggs and larvae, the microlayer has great economic value.

In a Georgia salt marsh, 21-43% of the total productivity is concentrated in the upper 0.55 mm. Average productivity (measured by oxygen consumption) was 3000 times greater in the microlayer than in the water below.[1]

Unfortunately, the sea-surface microlayer is specially vulnerable to pollution. Contaminants that settle out from the air (such as emissions from incinerators, or from combustion of gasoline or coal) tend to accumulate in the microlayer. So do contaminants deposited on the land, many of which eventually wash into rivers and then the oceans.

Toxins in the microlayer typically occur at concentrations 100 to 10,000 times higher than in the water below.[1]

Contaminants that have low solubility in water or that attach to floatable particles (chlorinated hydrocarbons, pesticides and metals) concentrate in the microlayer. Concentrations of these contaminants hundreds or even thousands of times greater than EPA water quality standards have been measured in the sea-surface microlayer of Puget Sound, Chesapeake Bay and elsewhere.[2]

Contaminants build up in the microlayer. Combustion byproducts called polycyclic aromatic hydrocarbons (PAHs) in the Lake Michigan microlayer range from 0.15 to 0.45 ppb [parts per billion], a million-fold enrichment compared to the air above.[1] The surface film of Biscayne Bay, Florida, contained 2670 times higher concentration of DDT compared to the water below.[1] In a San Francisco salt march, lead was measured at a concentration 6 to 14 times higher than in the water below[1] and in Narragansett Bay lead was 5 times more concentrated in the surface microlayer than in the water below.[1]

Atmospheric deposition (fallout) accounts for around 50% of the PAHs and metals entering some coastal waters.[3] As airborne particles settle onto the surface of a water body, they become solubilized and are rapidly introduced into the food chain via the high concentration of microorganisms found in the microlayer.

Fish eggs are sensitive to environmental toxicants. So are embryos and larvae, which are deformed or killed by hydrocarbons, metals, and pesticides.[2] In the ocean, most fish eggs, because of their high content of lipids (fat or oil), float on the surface in direct contact with the microlayer.[2] Careful measurements in Puget Sound have shown that the hatching success of larvae decreases with increasing concentration of PAHs and heavy metals in the microlayer. Significant contamination of the microlayer is considered to be any concentration greater than 1 ppb PAHs and greater than 50 ppb metals. By this criterion, in Chesapeake Bay, 30% of samples of the microlayer were highly contaminated.[2]

The killing power of contaminants in the microlayer is exemplified by benzo(a)pyrene, or BaP, one of the PAHs. BaP is a strong carcinogen created by the combustion of coal, gasoline, and many wastes, including municipal trash. Experiments have shown that 0.3 ppb of benzo(a)pyrene causes 2 to 5 times more misshapen trout larvae than normal. There was a 30% death rate among sole embryos exposed to 0.1 ppb benzo(a)pyrene. Yet in Puget Sound many samples from the sea-surface microlayer measured 3 to 123 ppb benzo(a)pyrene.[3]

Samples of the sea-surface microlayer from Los Angeles harbor induced severe malformations in 100% of surviving larvae of kelp bass.[2]

A contaminated microlayer can be carried by wind and surface currents and deposit on beaches and along shallow coastlines where it can contaminate shellfish and other species, such as herring, that lay their eggs in such areas.[2]

U.S. Environmental Protection Agency water quality criteria for PCBs is 30 parts per trillion (ppt). But sea-surface microlayer concentrations of PCB in Puget Sound are up to 130 times higher than EPA's water quality criterion.[3]

In Puget Sound in 1985 PAHs, which are carcinogenic, mutagenic and teratogenic occurred in the majority (57%) of sea-surface microlayer samples. Pesticides were detected in 28% of the sea-surface microlayer samples.[3]

In controlled tests, more than half the samples from the Puget Sound microlayer caused a significant reduction in the normal hatching success of fertilized sole eggs.[3]

There seems to be little doubt that incineration, the combustion of petroleum products, and of coal, is greatly reducing the productivity of near-shore regions of the world's oceans. Unfortunately, these near-shore regions are the most important from the viewpoint of productivity.

The consequences of this contamination are real. At a fish store in Washington, DC, flounder now sells for $10 per pound, red snapper for $12 per pound. At these prices, only the wealthiest among us can afford to eat fish regularly. Until recently, fish was a free or low-cost source of protein.

Fortunately, a possible legal mechanism already exists to protect the oceans from land-based incineration.

In the FEDERAL REGISTER Vol. 39 (October 17, 1974), pg. 37058, EPA (U.S. Environmental Protection Agency) stated that "in any case where it can reasonably be anticipated that incineration of wastes at sea will result in any such material, or emissions from the incineration of such material, entering ocean waters, such incineration will require a permit under the Ocean Dumping Act [the Marine Protection, Research and Sanctuaries Act, 33 U.S.C. 1401-1444].

In a court case, EPA argued that incineration on ocean-going ships constituted ocean dumping because incinerator emissions would enter the oceans. The case was Seaburn, Inc. vs. United States Environmental Protection Agency, Civ. A. No. 88-637, United States District Court, District of Columbia, April 20, 1989. Seaburn, a waste disposal company, had challenged EPA's decision to suspend its evaluation of the company's application for an ocean-incineration permit. The District Court held that the Agency's interpretation of the Ocean Dumping Ban Act, to equate ocean incineration dumping with ocean dumping, was reasonable. On pg. 7 of its motion for summary judgement the EPA argued that "Ocean incineration is a process that converts some of the liquid wastes into "residues" or emissions which are then "dispersed into the atmosphere and generally deposited into the ocean." Thus, the EPA argued, ocean incineration is really a form of ocean dumping.

The same logic leads to the conclusion that land-based incineration anywhere within several hundred miles of an ocean constitutes ocean dumping. U.S. policy on ocean dumping is firmly established: it is banned. It is time to ban incineration too.
--Peter Montague, Ph.D.

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[1] J.T. Hardy, "The Sea Surface Microlayer: Biology, Chemistry, and Anthropogenic Enrichment," PROGRESS IN OCEANOGRAPHY Vol. 11 (1982), pgs. 307-328.

[2] John Hardy and others, "The Sea-surface Microlayer of Puget Sound: Part I. Toxic Effects on Fish Eggs and Larvae." MARINE ENVIRONMENTAL RESEARCH Vol. 23 (1987), pgs. [227-249.]227-249.

[3] J.T. Hardy and others, "The Sea-surface Microlayer of Puget Sound: Part II. Concentrations of Contaminants and Relation to Toxicity." MARINE ENVIRONMENTAL RESEARCH Vol. 23 (1987), pgs. 251-271.

[4] Jeffrey N. Cross and others, "Contaminant Concentrations and Toxicity of Sea-surface Microlayer Near Los Angeles, California," MARINE ENVIRONMENTAL RESEARCH Vol. 23 (1987), pgs. 307-323.

[5] 712 F. Supp. 218 (D.C.C. 1989). Thanks to Rick Parrish of Charlottesville, VA, for alerting us to this important court case and EPA opinion.

Descriptor terms: water pollution; incineration; waste disposal technologies; puget sound; chesapeake bay; los angeles harbor; wildlife; ga; fish; pahs; heavy metals; water quality;