Researchers continue to study the extent and effects of Kepone contamination caused by a Hopewell, Va., plant that produced the pesticide until 1975. The trail leads hundreds of kilometers, through the biota and sediments of the James
Robert J. Huggett Michael E. Bender Virginia Institute of Marine Sciences Gloucester Point, Vu. 23062
On July 18, 1975, the Center for Disease Control in Atlanta notified the Virginia state epidemiologist that a Hopewell, Va., pesticide-plant worker who showed symptoms of neurological illness had been found to have Kepone in his blood in the parts-per-million range. Within a week, the state issued an order to the manufacturer, Life Sciences Products (LSP), Inc., to cease production of Kepone. LSP voluntarily complied. But that was by no means the end of 918
Environmental Science & Technology
the story. In addition to epidemiological evaluations of past and present employees of LSP, environmental sampling was carried out in the adjacent James River. The samples were sent to the EPA laboratory a t Research Triangle Park, N.C., for analysis, and by mid-December the initial results, though still sketchy, indicated that the pesticide had inundated the tidal river and estuary (Figure 1). A meeting was held to brief state officials and scientists of the extent of the contamination. Concentrations as high as 2.1 p g / g (wet weight) were reported in finfish and 0.48 gg/g in oysters (EPA, 1975). Kepone, decachlorooctahydro1,3,4 - metheno-2H-cyclobuta[cd]pentalen-2-one, is a pesticide patented by Allied Chemical Company in 1952.
It was registered to control ants and cockroaches, but was mostly exported to Central and South America (via Germany) to poison the banana root borer which attacked the economically important banana trees in the region (NAS, 1978). Allied Chemical began producing Kepone in Hopewell in 1966. Manufacture occurred intermittently until 1974, when LSP, then a recently formed company, began production trials in the same city. The production rates are given in Table 1. The major source of Kepone conF e ~ t i r rarticles ~ i n ES&T hare bjs-lines. repre.rent the ciews ofthe a u t h o n , and are edited
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tamination in Virginia was the Hopewell plants. However, the compound also is generated in the production and degradation of Mirex, a similar cyclodiene insecticide ( N A S , 1978); since Mirex was used for the control of fire ants in the southeastern United States as well as manufactured in the Northeast as a fire retardant under a different common name, declorane, many environmental samples collected outside Virginia showed trace levels of Kepone. The human health implications of Kepone on the industrial workers and those who consumed contaminated seafood are beyond the scope of this paper. Recommended references for interested readers are Cannon et al., 1978; Taylor et al., 1978.
Contaminated soil, air The preliminary survey, as reported by the EPA, not only indicated that biota of the James River was contaminated, but also that the dust over Hopewell, collected approximately one block from LSP, ranged 1-4070 Kepone by weight. The soils immediately surrounding the plant were contaminated to levels of 1-270 and contamination extended to 1000 m a t levels of 2-6 pg/g. These data, along with the fact that a number of L S P employees were hospitalized with “Kepone Shakes,” as it was called by the workers, gave Governor Mills Godwin no alternative but to close the entire tidal James River and its tributaries for the harvest of shellfish and finfish to protect public health. At this point, action levels for Kepone had yet to be established by the EPA and approved by the FDA. Only a few of the scores of edible species in the James had been sampled and analyzed; the extent of the health threat was almost totally unknown. For the first several months after the closure, scientific efforts focused on James River mollusks, since water temperatures were not warm enough for anadromous and marine fishes to enter the Chesapeake Bay. While on the surface the closure of the James River seemed disastrous because scores of watermen were out of work, an even more important aspect became apparent: The private oyster industry in Virginia depended almost exclusively on seeds from the lower James River. Oystermen farm oysters just as farmers raise crops, and the lower James River has historically produced abundant seed oysters, juvenile animals of 1-6 cm in length. These are harvested and sold to watermen from other areas of the Bay to be planted in
their waters. The animals grow to market size, usually in three years, and are harvested and sold. It is estimated that 70% of the annual oyster production from private oyster grounds in Virginia is dependent on seeds from the James. T o ensure a crop in 1979, the seed harvest of 1976 could not be interrupted. Oysters are filter-feeding animals with the ability to pump over 500 L of water per day over and through their gills, and therefore often concentrate contaminants from the environment. They can purge or depurate themselves of some chemical contaminants if placed in clean water for several weeks. We attempted to determine if Kepone could likewise be purged. The experimental design involved collecting contaminated animals from the James and placing them in Kepone-free water of various temperatures in the laboratory. Subsequent sampling and analyses showed that with summer
temperatures, oysters need about two weeks to purge themselves; with winter temperatures, seven weeks (Huggett et al., 1980). The experimental conclusions were validated by analyzing oysters from the James which had been transplanted into other rivers for varying periods of time. As a result of these experiments, harvesting seed oysters in the James was permitted. Opening the James to oystering relieved the policy pressures for a short period since most commercial fishes were still at sea. During February and March 1976, FDA adopted action levels for Kepone in seafood. Concentrations on a wet weight basis of 0.1 F g / g in the edible portion of finfish, 0.3 p g / g in mollusks, and 0.4 p g l g in edible portions of blue crabs were deemed “safe.” I n the original computations it was assumed that the pesticide had contaminated other foodstuffs such as dairy products and vegetables. Allowances therefore were made for part
FIGURE 1
The Chesapeake Bay and the James River 77°100‘
76.100‘
Volume 14, Number 8, August 1980
919
Kepone Decachlorooctahydro-1 3 4-metheno-2H-cyclobuta (cd) pentaten-2-one
- A chlorinated hydrocarbon insecticide
TABLE 1
Kepone production in Virginia Year
1966 1967 1968 1969 1970 1971 1972 1973 1974 1975
Production (kg)
35 935 47 990 36 535 46 990 41 460 204 800 176 970 100 435 457 630 384 020 1 532 265
Source: Sales records, Allied ChemicalGo. and Life Sciences Products, Inc. (EPA. 1978a)
of the maximum permissible intake to come from these nonseafood items. Subsequent sampling and analyses showed only marine life was contaminated, and in March 1977 the action level for finfish was raised from 0.1 P E l g to 0.3 PLplg. Increasing the action level for finfish had little impact on the James River fishery. Fish in this estuary often contain two or more times the 0.3 p g l g limit. Some fish species are exceptions to the rule; the American shad (Alosa sapidissima), for instance, is a shortterm resident which eats little on its run from the ocean into the freshwater portion of the river to spawn. Therefore, the animal receives Kepone only from that portion dissolved in water. During the 1976 spawning run, intensive sampling and analyses showed that the animals entered the James with nondetectable levels, but that the levels increased the longer they remained and the further upstream they migrated. Under the 1976 action level of 0.1 p g / g for fish, harvest was allowed only in the lower 40 km of the river. The 0.3 pg/g action level allows shad fishing in the entire river. The intensive monitoring of shad resulted in our noticing another phenomenon of Kepone in marine life. Of the fish whose flesh exceeded the action level, 85% were males. Our hy920
Environmental Science & Technology
pothesis for this centers around the fact that the females were gravid and contained about 20% of their total weight as eggs. A significant portion of the Kepone taken up by females is transferred to the egg mass rather than concentrated in the flesh. Analyses of roe and flesh from the same fish showed that the eggs contained about the same concentration as the flesh or slightly greater. Roberts and Leggett ( 1 980) have collected blue crabs (Callinectes sapidus) from various locations in the southern Chesapeake Bay and James River and have shown that gravid females also transfer Kepone from their bodies to the eggs. This explains w h y male crabs usually exceed females in Kepone concentration. Considerable variations in Kepone residues occurred between species in the James River. These variations were in part accounted for by the different life histories of the species. Freshwater fishes-permanent residents of the upper river-exhibited the widest range in flesh concentrations, varying from 210 pgIL, respectively. Roberts and Bend1 ( 1 980) determined a 96-hour LCso for menhaden (Breuoortia tyrannus), silversides (Menidia menidia), eels (Anguilla rostrata), bluegill sunfish (Lepomis macrochirus), and channel catfish at 17.7 p g l L , 27.5 p g / L , 34.6 pg/L, 49.6 p g / L , and 5 13.5 p g / L , respectively. Schimmel et al. (EPA, 1978b) reported mortality in blue crabs during a 28-day study when crabs were exposed via diet to levels of 0.15 p g / g and 1.9 p g l g . However, in a study designed to determine the dietary LCso for Kepone in blue crabs, Fisher ( 1 980) could not demonstrate Kepone-related mortalities after 65 days of exposure to 0.5 pg/day. The chronic effects of Kepone on two estuarine animals have been studied. Nimmo et al. (EPA, 1978b), using growth as a measure of effect, determined that the safe exposure level for mysid shrimp (Mysidopsis bahia) was 0.026 pg/L. Growth of sheepshead minnows was affected by exposure to 0.08 p g / L (Hansen et al. (EPA, 1978b)).
Buckler et al. ( 1 980) found a 96hour LCjo of 340 p g / L and a maximum acceptable toxicant concentration of 1.2 p g / L for the freshwater fathead minnow (Pimephales promelas). Based on these results, the application factor-the ratio of the estimated safe concentration to the acutely toxic concentration-was calculated for each species. These factors are 0.003 for the mysid, 0.004 for fatheads, and less than 0.01 for the sheepshead minnow. By applying the factor of 0.004 to the most sensitive species tested in the James, we predicted maximum acceptable concentrations for dissolved Kepone of 0.14 p g / L in the freshwater zone and 0.026 p g / L in the lower estuary. N o measurements of dissolved Kepone have been made in the lower estuary, but levels of 3-10 ng/L were observed in the middle estuary (Harris et al., 1980). Kepone levels as high as 45 ng/L were reported in the upper freshwater zone (Saleh et al., 1978 and EPA, 1978a). It appears, therefore, that dissolved Kepone levels were below those a t which chronic effects were predicted. However, since Kepone-contaminated food serves as an additional source for the animals, we believe the potential for ecological damage cannot be dismissed. Waterfowl that winter on the James River and water birds that are permanent residents accumulated Kepone in their tissues. The concentration reached by the various species reflects feeding habits. Canadian geese which feed mainly in fields show the lowest concentration, while Blue Heron-fish eaters-contain the most. Table 3 lists the wet-weight concentrations found in bird livers collected a t the Hog Island Wildlife Refuge (Figure 1) in 1976 and 1977. Birds higher up the food chain have also been shown to contain the compound. Osprey (Pandion haliaetus) eggs collected from nests outside the James River contained Kepone residues ranging from 0.05 p g / g to 1.5 p g l g . Bald eagle (Haliaeetus leucocephalus) livers collected from birds in Virginia and Maryland contained Kepone ranging from nondetected to 130 p g l g , with lower concentrations usually coming from birds taken in Maryland (Stafford et al., 1978). White-footed mice (Peromyscus leucopus noueboracensis) collected from Jamestown Island, which borders the James, and from wooded areas in Williamsburg, approximately 5 km from the river, contain Kepone. Terman et al. (1980) have shown that livers from mice collected adjacent to the river contain 0.74-5.9 p g / g Kep-
one, while those collected 5 km away contain
