Journal Article Citations and Abstracts

A method for measuring fenthion in samples from the estuarine environment is described. The method was applied to samples from the field applications of fenthion to control salt-marsh mosquitos. The method offers an improvement in the silica gel cleanup of Thompson et al. and yields >85% recovery of fenthion from water, plant, fish, and shrimp tissues. Gas-liquid chromatography with thermionic detection was used to quantify fenthion residues as low as 0.010 µg/l in seawater and 0.010 µg/g in biota. Concentration of fenthion residues ranged from undetectable to 0.68 µg/l in saltwater samples collected after truck-mounted ultra-low-volume or aerial spraying to control salt-marsh mosquitos.

Moore, James C., David J. Hansen, Richard L. Garnas and Larry R. Goodman. 1985. Sand/Granular Carbon Filtration Treatment System for Removing Aqueous Pesticide Residues from a Marine Toxicology Laboratory Effluent. EPA/600/J-85/271. Water Res. 19(12):1601-1604. (ERL,GB 481). (Avail. from NTIS, Springfield, VA: PB86-157799)

Flow-through toxicity tests using marine organisms can generate large volumes of contaminated seawater effluent which should be treated to remove the contaminants before discharge into the environment. We have developed a sand filtration/carbon treatment system that removes from these effluents a diversity of organophosphate, organochlorine and pyrethroid pesticide residues down to their detection limit. The sand filter removed an average of 72% (range 4-99%) of the chemicals by continuously filtering suspended particulates and chemicals associated with the particulate. Following sand filtration, effluent water slowly percolates through granular carbon. Overall, organic removal efficiencies average 91% (range 24-99%). Initial construction cost was less than $20,000.

O'Neill, Ellen J., Carol A. Monti, Parmely H. Pritchard, Al W. Bourquin and Donald G. Ahearn. 1985. Effects of Lugworms and Seagrass on Kepone (Chlordecone) Distribution in Sediment/Water Laboratory Systems. EPA/600/J-85/150. Environ. Toxicol. Chem. 4(4):453-458. (ERL,GB 488). (Avail. from NTIS, Springfield, VA: PB86-101078)

The influence of lugworms (Arenicola cristata Stimpson) and seagrass (Thalassia testudinum Koenig) on Kepone® (chlordecone) distribution in sediment/water systems was examined. Radiolabeled Kepone was introduced into continuous-flow sediment/water systems, and the dissolved and sorbed concentrations of Kepone were quantified. Lugworm activity decreased the Kepone concentration in the water and increased its concentration in the sediment. The presence of seagrasses did not appreciably affect the concentration of Kepone in the water. Bioturbation appeared to be the prime factor in the transport of Kepone from water to sediment.

McMullen, Dennis M. and Douglas P. Middaugh. 1985. Effect of Temperature and Food Density on Survival and Growth of Menidia peninsulae Larvae (Pisces: Atherinidae). EPA/600/J-85/052. Estuaries. 8(1):39-47. (ERL,GB 489). (Avail. from NTIS, Springfield, VA: PB85-210102)

Day of hatch tidewater silversides, Menidia peninsulae, were stocked at 5 fish per liter in 3 l of seawater at 30o/oo and raised for 16 days at 20°, 25° and 30° C. Food organisms (Brachionus sp. or Artemia nauplii) were maintained at 500, 1,000, 5,000 or 10,000 organisms per l. The influence of food density on growth of larval M. peninsulae was temperature dependent. At 20° C, there was no difference in final size of fish based on food densities. But at 25° and 30° C there was an increase in final body size as food density increased. There were no significant differences in survival among food densities in tests at 20°, 25° or 30° C. However, for any given temperature and food density, the number of survivors in a replicate affected the final size attained. Optimal culture condition for larval M. peninsulae, considering both survival and growth was determined to be 5,000 food organisms per l at 25° C.

Yingst, Josephine Y. and Donald C. Rhoads. 1985. Structure of Soft-Bottom Benthic Communities in the Vicinity of the Texas Flower Garden Banks, Gulf of Mexico. EPA/600/J-85/176. Estuarine Coastal Shelf Sci. 20:569-592. (ERL,GB 503).

Biological and sedimentological samples were obtained in June 1980 from box cores taken in 100-200 m of water on sandy-mud sediments near the East and West Flower Garden Bank reefs, on the Texas-Louisiana Continental Shelf. The objective was to obtain baseline information about sedimentary parameters and organisms adjacent to the FGB environments in order to allow inferences to be made about the potential effects of physical disturbance of the seafloor on the resident benthos. Most infaunal organisms are found in the upper 3 to 5 cm of the bottom. Permanent meiofauna dominate in both numbers and biomass. X-radiographs of sediment fabrics show all stations to be reworked by head-down deposit-feeders or errant bioturbators. Taxa responsible for this bioturbation were not quantitatively sampled. Macrofaunal densities range from 3000 to 25000 m-2 and total meiofauna from 221 to 892x(10cm)-2. Nematodes dominate followed in equal abundance by foraminifera, polychaeta, and copepods. Seventy-five percent of the total sediment ATP in the top 3 cm is contributed by meiofauna. These benthic assemblages are hypothesized to represent a mixture of pioneering and high-order successional stages. Bacterial abundances are positively correlated with organic content and inversely correlated with macro- and meiofaunal densities. This inverse relationship may reflect consumer cropping intensities. Both microbial ATP and bacterial biomass are lower than reported for the Georgia Bight Shelf, Cape Blanc, West African Shelf, western coast of Norway, and Long Island Sound. Bacterial counts are lower than those recorded for the East China Sea and the Amazon River shelf. Moderate to low standing stocks of benthos, dominated by meiofaunal-sized taxa, further suggest that this area of the Gulf of Mexico is a relatively oligotrophic system for infaunal benthic consumers. Higher order successional stages are in general adversely affected to a greater extent than pioneering stages by physical disturbance. In the Texas-Louisiana shelf region, dilution of an already food limited system by inert barium sulphate would be expected to result in even lower standing stocks of benthic infaunal invertebrates.

Tagatz, Marlin E., Gayle R. Plaia and Christine H. Deans. 1985. Responses of Macrobenthos Colonizing Estuarine Sediments Contaminated with Drilling Mud Containing Diesel Oil. EPA/600/J-85/125. Bull. Environ. Contam. Toxicol. 35(1):112-120. (ERL,GB 505). (Avail. from NTIS, Springfield, VA: PB86-100294)

Boxes filled with clean sand or clean sand with a 2-cm overlay of mixtures of sand with barite or drilling mud were placed in Santa Rosa Sound, Florida, to determine the effects of a used lime drilling-mud on field-colonized macrobenthic communities. Effect of the drilling mud on community structure was greater than that of its barite component after colonization for 8 weeks. Barite causes changes in texture of the sediment and thereby recruitment. The average numbers of animals and species in boxes containing 1:10 and 1:3 mixtures of mud to sand were significantly less than those in control boxes and most of the barite/sand mixtures. The Shannon-Weaver index of diversity, Simpson's index of dominance, and the Bray-Curtis dissimilarity index differed only for 1:3 mud/sand communities. Toxic effects of the lime drilling mud were attributed to a diesel fuel oil component (3.98 mg/g of mud).

Goodman, L.R., D.J. Hansen, G.M. Cripe, D.P. Middaugh and J.C. Moore. 1985. New Early Life-Stage Toxicity Test Using the California Grunion (Leuresthes tenuis) and Results with Chlorpyrifos. EPA/600/J-85/186. Ecotoxicol. Environ. Saf. 10(1):12-21. (ERL,GB 516). (Avail. from NTIS, Springfield, VA: PB86-120540/AS)

California grunion were continuously exposed as embryos and fry to technical chlorpyrifos in two toxicity tests conducted in the same exposure apparatus. The first test, a 35-day early life-stage (ELS) test, began with approximately 2.5-day-old embryos that were exposed in flow-through aquaria in darkness until hatching was stimulated on Day 9 of exposure. The second toxicity test, a fry test, began with newly hatched fry and lasted 26 days. Test water temperature ranged from 23 to 26°C and salinity from 24.5 to 34.0 o/oo. Results of the two tests were similar, indicating that exposure of embryos added little to the overall toxicity of chlorpyrifos to grunions. Percentage hatch of embryos was unaffected by the chlorpyrifos concentrations tested. Fry survival was apparently reduced in nominal concentrations >=1.0 µg/liter in both tests, but significantly so in concentrations >=1.0 µg/liter in the ELS test and >=2.0 µg/liter in the fry test. When compared with carrier controls, mean fish weights were significantly reduced in nominal chlorpyrifos concentrations >=0.5 µg/liter in the ELS test and >= to 1.0 µg/liter in the fry exposure. Mean bioconcentration factors were 770X for fish that survived the ELS test and 190X for those that survived the fry test. Results demonstrate the practicality of conducting ELS tests for the first time with a marine fish from the Pacific coastal waters of the United States.

Borthwick, Patrick W., James M. Patrick, Jr. and Douglas P. Middaugh. 1985. Comparative Acute Sensitivities of Early Life Stages of Atherinid Fishes to Chlorpyrifos and Thiobencarb. EPA/600/J-85/122. Arch. Environ. Contam. Toxicol. 14(4):465-473. (ERL,GB 517). (Avail. from NTIS, Springfield, VA: PB86-100278/AS)

Sensitivity, expressed as the 96-hr LC50 derived from acute lethality tests, was compared for four ages (day-of-hatch, 7-day, 14-day, and 28-day) of three atherinid fishes: Leuresthes tenuis (California grunion), Menidia menidia (Atlantic silverside), and Menidia peninsulae (tidewater silverside). Responses of each age-species combination exposed to the organophosphate insecticide chlorpyrifos and the carbamate herbicide thiobencarb were compared in both static and flowing seawater toxicity tests. Chlorpyrifos was highly toxic to all atherinids (96-hr LC50's ranged from 0.4 to 6.7 µg/L); toxicity of thiobencarb was approximately two orders of magnitude lower (LC50 values from 199 to 1,405 µg/L). Responses to each pesticide were similar among the three species. Sensitivity was generally highest for 7-day and 14-day age groups, and flowing water tests were more sensitive measures of toxicity than static tests, especially for chlorpyrifos. Comparisons of three computational methods indicate that probit and moving average methods calculate comparable LC50 estimates with the binomial method being the least uniform point estimator.

Walsh, Gerald E., Leslie L. McLaughlin, Emile M. Lores, Michael K. Louie and Christine H. Deans. 1985. Effects of Organotins on Growth and Survival of Two Marine Diatoms, Skeletonema costatum and Thalassiosira pseudonana. EPA/600/J-85/044. Chemosphere. 14(3/4):383-392. (ERL,GB 522). (Avail. from NTIS, Springfield, VA: PB85-220374)

Tributyl- and triphenyltin compounds inhibited population growth and cell survival of marine unicellular algae at low concentrations. They may pose a threat to algae in areas of industrial outfalls and heavy boat traffic.

Clark, J.R., D.P. Middaugh, M.J. Hemmer, B.W. Clements, Jr., J.C. Dukes and C.B. Rathburn, Jr. 1985. Effects of Ground ULV Applications of Fenthion on Estuarine Biota: I. Study Design and Implementation. EPA/600/J-85/464. J. Fla. Anti-Mosquito Assoc. 56(2):51-62. (ERL,GB 523A). (Avail. from NTIS, Springfield, VA: PB87-152567)

On the evenings of 5 May, 10 May, 13 June and 11 July, 1983, truck-mounted ULV equipment was used to apply fenthion at a rate of 11 g/ha to control adult salt marsh mosquitoes at two sites. Meteorological conditions at the time of spray, spray droplet density, and droplet VMD were monitored. Mortality of caged Aedes taeniorhynchus and Culex quinquefasciatus was measured to evaluate spray effectiveness. Sand dunes and stands of pine trees affected wind speed and directions and reduced effectiveness during some sprays. When appropriate conditions prevailed, 100% mortality was achieved among caged mosquitoes placed up to 150 m from the spray source. These data provided the efficacy baseline for studies on nontarget species.

Moore, James C., E.M. Lores, James R. Clark, P. Moody, J. Knight and J. Forester. 1985. Effects of Ground ULV Applications of Fenthion on Estuarine Biota: II. Analytical Methods and Results. EPA/600/J-85/461. J. Fla. Anti-Mosquito Assoc. 56(2):62-68. (ERL,GB 523B). (Avail. from NTIS, Springfield, VA: PB87-152773)

Methods of analyses were validated for quantitating fenthion residues in samples from two salt marsh sites subjected to ground ultra-low volume sprays. Concentrations of these residues were followed from the water's surface, through the water column and onto the sediment. For all sprays, the highest concentration, detected in the upper portion of the water column, was 0.48 µg/l and occurred within the first hour after spraying. Detectable concentrations (>0.010 µg/l) of fenthion persisted in the water for up to 24 h. Fenthion did not accumulate to a detectable level (0.010 µg/g) in tissues of caged shrimp or fish.

Borthwick, Patrick W. and Roman S. Stanley. 1985. Effects of Ground ULV Applications of Fenthion on Estuarine Biota: III. Response of Caged Pink Shrimp and Grass Shrimp. EPA/600/J-85/463. J. Fla. Anti-Mosquito Assoc. 56(2):69-72. (ERL,GB 523C). (Avail. from NTIS, Springfield, VA: PB87-152781)

Estuarine grass shrimp (Palaemonetes pugio) and pink shrimp (Penaeus duorarum) were deployed in floating cages to determine if fenthion, in an actual-use application in the field, affected shrimp survival. After four ultra-low-volume ground applications (equivalent to 11g/ha or 0.01 lb/acre) to control salt marsh mosquitoes, deaths of caged grass shrimp or pink shrimp were not attributed to fenthion exposure. Suspect causes of reduced survival of shrimp include both low salinity and dissolved oxygen, daily excursions in water temperature, and stresses due to handling, acclimation, and confinement. Initial fenthion concentrations in seawater were sometimes within the range expected to kill shrimp in 48-h and 96-h laboratory exposures; however, pesticide concentrations were not sustained long enough to kill caged shrimp in the field. No signs of fenthion poisoning were observed among any of the caged shrimp.

McKenney, C.L., Jr., E. Matthews, D.A. Lawrence and M.A. Shirley. 1985. Effects of Ground ULV Applications of Fenthion on Estuarine Biota: IV. Lethal and Sublethal Responses of an Estuarine Mysid. EPA/600/J-85/462. J. Fla. Anti-Mosquito Assoc. 56(2):72-75. (ERL,GB 523D). (Avail. from NTIS, Springfield, VA: PB87-152799)

Low-level exposure to fenthion, following ground ULV application of this organophosphate pesticide, resulted in increased mortality and sublethal growth retardation of Mysidopsis bahia. These two processes would reduce population production of this crustacean, which serves as an important link in the estuarine food web. Significantly higher rates of oxygen consumption of exposed mysids 8 days after fenthion application accompanied the reduced growth of exposed mysids. The results of this field study confirm those of earlier laboratory studies, indicating that short-term measurements of metabolic dysfunction in mysids exposed to pesticides may be used to predict altered production rates in mysid populations.

Tagatz, Marlin E. and Gayle R. Plaia. 1985. Effects of Ground ULV Applications of Fenthion on Estuarine Biota: V. Field and Laboratory Estuarine Benthic Communities. EPA/600/J-85/460. J. Fla. Anti-Mosquito Assoc. 56(2):76-81. (ERL,GB 523E). (Avail. from NTIS, Springfield, VA: PB87-152807)

The effects of fenthion on macrobenthic animals that colonized sand-filled boxes at two salt marsh sites were determined after two field sprayings within 5 days and in the laboratory after intermittent exposures that simulated field conditions. ULV ground applications for adult mosquito control resulted in water concentrations <=0.68 µg fenthion/l at one site and <=0.38 µg/l at the other site. There were no statistically significant differences (a= 0.05) in average numbers of benthic individuals and species (primarily annelids and arthropods) that colonized control communities and those exposed to these concentrations. The average numbers of individuals and species of animals that colonized sand-filled boxes in the laboratory (during 9 wk by planktonic larvae from continuously supplied unfiltered seawater) were not significantly affected by two treatments at 1.1 µg fenthion/l or by four treatments at 1.3 µg/l. However, the average number of species in communities exposed to two treatments at 11.8 µg/l was significantly less than that in control communities and those exposed to lower concentrations. Mean abundances of mollusks, arthropods, and chordates were substantially (19 or more percent), but not statistically significantly, lower in this concentration than in the control.

Lores, Emile M., James C. Moore, Paul Moody, James Clark, Jerrold Forester and J. Knight. 1985. Temephos Residues in Stagnant Ponds After Mosquito Larvicide Applications by Helicopter. EPA/600/J-85/185. Bull. Environ. Contam. Toxicol. 35(3):308-313. (ERL,GB 524). (Avail. from NTIS, Springfield, VA: PB86-120516, A02)

This paper has shown that temephos, in actual field applications as a mosquito larvicide, behaves in much the same way as was predicted by Henry et al. (1971) and Sanders et al. (1981). The results indicate that the pesticide remains intact in water up to 48 hours, and residues as high as 62 µg/l were found. A problem of stabilization in this study was overcome by using mineral oil as an extracting solvent until the samples could be returned to the laboratory. The two new methods presented for analysis, although similar to methods already published, incorporate some newer technology.

Middaugh, D.P., P.G. Hester, M.V. Meisch and P.M. Stark. 1985. Preliminary Data on Use of the Inland Silverside, Menidia beryllina, to Control Mosquito Larvae. EPA/600/J-85/376. J. Am. Mosq. Control Assoc. 1(4):435-441. (ERL,GB 532). (Avail. from NTIS, Springfield, VA: PB86-187382)

A study of procedures for spawning and culture of the inland silverside, Menidia beryllina, was conducted. The efficacy of young Menidia, 20 to 22 and 31 to 33 days old, to control mosquito larvae was determined in the laboratory with first and second larval instars of the saltmarsh mosquito Aedes taeniorhynchus. Feeding trials were run at salinities of 1, 5, 15 and 25 o /oo. Field trials were also conducted to determine if Menidia would effectively control Culex quinquefasciatus in brackish water impoundments.

Tagatz, M.E., G.R. Plaia and C.H. Deans. 1985. Effects of 1,2,4-Trichlorobenzene on Estuarine Macrobenthic Communities Exposed via Water and Sediment. EPA/600/J-85/337. Ecotoxicol. Environ. Saf. 10(3):351-360. (ERL,GB 535). (Avail. from NTIS, Springfield, VA: PB86-171626)

Macrobenthic animal communities that colonized sand-filled aquaria were exposed to 1,2,4-trichlorobenzene (TCB), a recent replacement for polychlorinated biphenyls in the electrical industry. In one test, communities established by planktonic larvae entrained in continuously supplied unfiltered seawater for 50 days were exposed to waterborne TCB for 6 days; in the second test, the toxicant was added to the sediment before 8 weeks of colonization. Concentrations that affected community structure were usually two orders of magnitude lower for waterborne TCB than for sediment-bound TCB, but the same types of organisms were affected by each route of exposure. The lowest TCB concentrations (measured) that affected average numbers of individuals exposed via the water were 0.04 mg/liter for mollusks, 0.4 mg/liter for arthropods, and 4 mg/liter for annelids. Average number of species was significantly lower than the control at 4 mg/liter. For TCB exposures via the sediment, the lowest concentrations (nominal) that affected average numbers of individuals were 100 µg/g for mollusks and echinoderms, and 1000 µg/g for arthropods and annelids. Average number of species in experimental aquaria was significantly lower than the control at >= 100 µg/g. TCB persisted in sediments, but some leached into water throughout the 8-week exposure via sediment.

Reish, Donald J., Philip S. Oshida, Alan J. Mearns, Thomas C. Ginn, Robert Scott Carr, Frank G. Wilkes and Nancy Butowski. 1985. Effects on Saltwater Organisms. EPA/600/J-85/149. J. Water Pollut. Control Fed. 57(6):699-712. (ERL,GB 536). (Avail. from NTIS, Springfield, VA: PB85-106342)

Published literature on the effects of pesticides and metals on marine animals is reviewed. Results are summarized of studies related to environmental effects of offshore mining, dredging and dumping, and drilling. Occurrence of diseases in saltwater organisms also is discussed.

Couch, John A. and John C. Harshbarger. 1985. Effects of Carcinogenic Agents on Aquatic Animals: An Environmental and Experimental Overview. EPA/600/J-85/123. J. Environ. Sci. Health Part C Environ. Carcinog. Rev. 3(1):63-105. (ERL,GB 540). (Avail. from NTIS, Springfield, VA: PB86-100286/AS)

A major underlying motivation for seriously studying carcinogenesis in aquatic animals is the concept of utilizing selected lower animal species as models in understanding neoplasia and the neoplastic process. Numerous examples may be cited which illustrate the contribution that ectothermic animals, as models, have made to the principles of pathology, physiology, biomedicine, and now, perhaps, oncology. The purpose of this paper is to provide an overview of the present status of bivalve molluscs and teleost fishes in environmental and experimental studies of carcinogens and cancer.

Clark, James R., James M. Patrick, Jr., Douglas P. Middaugh and James C. Moore. 1985. Relative Sensitivity of Six Estuarine Fishes to Carbophenothion, Chlorpyrifos, and Fenvalerate. EPA/600/J-85/336. Ecotoxicol. Environ. Saf. 10(3):382-390. (ERL,GB 541). (Avail. from NTIS, Springfield, VA: PB86-171634)

The acute toxicity (96-hr LC50) of carbophenothion, chlorpyrifos, and fenvalerate to six estuarine fishes was determined in flow-through laboratory tests. The atherinid fishes (Menidia menidia, M. peninsulae, M. beryllina, and Leuresthes tenuis) consistently were among the most sensitive species tested and were similar to each other in their sensitivity to pesticides. The sensitivity of sheepshead minnows (Cyprinodon variegatus) to carbophenothion was the same as that of the atherinids. For fenvalerate, the sheepshead minnow LC50 was an order of magnitude greater than that of the most sensitive atherinid, whereas the LC50 for chlorpyrifos and sheepshead minnows was two orders of magnitude greater. Gulf toadfish (Opsanus beta) were the least sensitive fish tested with carbophenothion and chlorpyrifos and their 96-hr LC50 for fenvalerate ranked between the LC50 for sheepshead minnows and atherinids. Test results were compared to acute toxicity data for other estuarine fishes and invertebrates.

Pritchard, P.H. 1985. Fate of Environmental Pollutants. EPA/600/J-85/148. J. Water Pollut. Control Fed. 57(6):658-667. (ERL,GB 544). (Avail. from NTIS, Springfield, VA: PB86-101060)

Published literature on the environmental fate of pollutants published during 1984 are reviewed. Short excerpts are presented from each reference covering such areas as photolysis, biodegradation, hydrolosis, sorption, and volatility for pollutants including pesticides, hydrocarbons, heavy metals, polynuclear hydrocarbons, and other toxic organic chemicals.

Price, Kent S., David A. Flemer, Jay L. Taft, Gail B. Mackiernan, Willa Nehlsen, Robert B. Biggs, Ned H. Burger and Dewey A. Blaylock. 1985. Nutrient Enrichment of Chesapeake Bay and Its Impact on the Habitat of Striped Bass: A Speculative Hypothesis. EPA/600/J-85/422. Trans. Am. Fish. Soc. 114(1):97-106. (ERL,GB X470). (Avail. from NTIS, Springfield, VA: PB86-208550)

Stocks of striped bass Morone saxatilis have declined in the Chesapeake Bay system over the last decade. We present evidence for the working hypothesis that the decline has resulted, in part, from loss of deep-water habitat for adults, caused by limiting concentrations of dissolved oxygen that are related, in turn, to nutrient enrichment and greater planktonic production. A related hypothesis is that changes in the near-shore habitat for juvenile striped bass, involving severe declines in submerged aquatic vegetation due to nutrient-driven planktonic shading, also have contributed to the decline of striped bass. Nutrients (nitrogen and phosphorus) and chlorophyll a, an indicator of phytoplankton biomass, have increased in many areas of the bay and tributaries over the past 20 to 30 years. These trends are qualitatively correlated with greater deoxygenation of the deep channel in the mid and upper bay. During the late 1970s, summer oxygen concentrations as low as 2 ml/liter approached to within 7-8 m of the surface, allowing water stressful to striped bass to intrude onto shoal areas of the bay. The volume of Chesapeake Bay bottom waters containing 0.5 ml O2/liter or less was about 15 times greater in July 1980 than in July 1950. The combination of the expanding hypoxic pool and summer temperatures above preferred levels for adult striped bass may contribute to an 'oxygen-temperature squeeze' that forces adults onto shoal areas of the bay or out of the upper bay. Many of these shoal areas now lack suitable cover for juvenile striped bass and their prey. Strong intraspecific competition among striped bass may be occurring there.

Alexander, Martin. 1985. Biodegradation of Organic Chemicals. EPA/600/J-85/014. Environ. Sci. Technol. 18(2):106-111. (ERL,GB X483).

The purpose of this article is to show that erroneous conclusions may be reached from studies or routine tests with organic chemicals at the levels often employed for predicting chemical fate in nature. These errors in extrapolation from high to low concentration may occur in routine evaluations of biodegradation, careful assessments of kinetics, or the establishment of products formed in water, soil, or sediments

Spain, J.C. and C.C. Somerville. 1985. Fate and Toxicity of High Density Missile Fuels RJ-5 and JP-9 in Aquatic Test Systems. EPA/600/J-85/020. Chemosphere. 14(2):239-248. (ERL,GB X486).

The high density missile fuels RJ-5 and JP-9 resisted biodegradation when incubated with water/sediment suspensions collected from aquatic habitats. RJ-5 and JP-9 were not toxic to the microbial communities at concentrations of 400 mg per liter, but RJ-5 was toxic to Mysidopsis bahia in 96-hour acute tests (LC50 88 ug/l).

Novick, Norman J. and Martin Alexander. 1985. Cometabolism of Low Concentrations of Propachlor, Alachlor, and Cycloate in Sewage and Lake Water. EPA/600/J-85/078. Appl. Environ. Microbiol. 49(4):737-743. (ERL,GB X487).

Low concentrations of propachlor (2-chloro-N-isopropylacetanilide) and alachlor [2-chlor-2', 6'-diethyl-N-(methoxymethyl)acetanilide] were not mineralized, cycloate (S-ethyl-N-ethylthiocyclohexanecarbamate) was slowly or not mineralized, and aniline and cyclohexylamine were readily mineralized in sewage and lake water. Propachlor, alachlor, and cycloate were extensively metabolized, but the products were organic. Little conversion of propachlor and alachlor was evident in sterilized sewage or lake water. The cometabolism of propachlor was essentially linear with time in lake water and was well fit by zero-order kinetics in short periods and by first-order kinetics in longer periods in sewage. The rate of cometabolism in sewage was directly proportional to propachlor concentration at levels from 63 pg/ml to more than 100 ng/ml. Glucose but not aniline increased the yield of products formed during propachlor cometabolism in sewage. No microorganism able to use propachlor as a sole source of carbon and energy was isolated, but bacteria isolated from sewage and lake water metabolized this chemical. During the metabolism of this herbicide by two of the bacteria, none of the carbon was assimilated. Our data indicate that cometabolism of these pesticides takes place at concentrations of synthetic compounds that commonly occur in natural waters.

Schmidt, Steven K. and Martin Alexander. 1985. Effects of Dissolved Organic Carbon and Second Substrates on the Biodegradation of Organic Compounds at Low Concentrations. EPA/600/J-85/077. Appl. Environ. Microbiol. 49(4):822-827. (ERL,GB X488).

Pseudomonas acidovorans and Pseudomonas sp. strain ANL but not Salmonella typhimurium grew in an inorganic salts solution. The growth of P. acidovorans in this solution was not enhanced by the addition of 2.0 ug of phenol per liter, but the phenol was mineralized. Mineralization of 2.0 ug of phenol per liter by P. acidovorans was delayed 16 h by 70 ug of acetate per liter, and the delay was lengthened by increasing acetate concentrations, whereas phenol and acetate were utilized simultaneously at concentrations of 2.0 and 13 ug/liter, respectively. Growth of Pseudomonas sp. in the inorganic salts solution was not affected by the addition of 3.0 ug each of glucose and aniline per liter, nor was mineralization of the two compounds detected during the initial period of growth. However, mineralization of both substrates by this organism occurred simultaneously during the latter phases of growth and after growth had ended at the expense of the uncharacterized dissolved organic compounds in the salts solution. In contrast, when pseudomanas sp. was grown in the salts solution supplemented with 300 ug each of glucose and aniline, in contrast, the sugar was mineralized first, and aniline was mineralized only after much of the glucose carbon was converted to CO2. S. typhimurium failed to multiply in the salts solution with 1.0 ug of glucose per liter. It grew slightly but mineralized little of the sugar at 5.0 ug/liter, but its population density rose at 10 ug/liter or higher. The hexose could be mineralized at 0.5 ug/liter, however, if the solution contained 5.0 mg of arabinose per liter. In solutions with this arabinose concentration and glucose levels too low to support growth, the percentage of glucose carbon incorporated into S. typhimurium cells was the same as when the bacterium was grown in solutions with high concentrations of glucose alone. When glucose was the only carbon source for S. typhimurium, the percentage of the glucose carbon assimilated and mineralized progressively declined as the sugar concentration was reduced to levels approaching the threshold for growth. These results indicate that second substrates and uncharacterized dissolved organic carbon may play an important role in controlling the rate and extent of biodegradation of organic compounds at low concentrations.

Wang, Yei-Shung, Eugene L. Madsen and Martin Alexander. 1985. Microbial Degradation by Mineralization or Cometabolism Determined by Chemical Concentration and Environment. J. Agric. Food Chem. 33(3):495-499. (ERL,GB X489).

Monuron [3-(4-chlorophenyl)-1,1-dimethylurea] was mineralized when added to sewage at a concentration of 10 ug/L but not a 10 mg/L. Organic products were formed at both concentrations. Products with the chromatographic characteristics of 4-chlorophenylurea and 4-chloroaniline were generated during the decomposition of the higher herbicide concentration. Diuron [3-(3,4-dichlorophenyl)-1, 1-dimethylurea] and linuron [3-(3,4-dichlorophenyl)-1- methoxy-1-methylurea] were mineralized when added to sewage at a concentration of 500 ng/L but not at 2.0 mg/L. No evidence for cometabolism of the higher levels of these two herbicides was obtained, but significant amounts of an unknown product appeared at the lower diuron levels. Chlorobenzilate (ethyl 4,4'-dichlorobenzilate) was cometabolized in water samples from Beebe Lake and mineralized if the samples also contained freshwater sediments. Mineralization did not occur if glucose and inorganic nutrients were added to sediment-free lake water. Chlorobenzilate was transformed to organic products but not to CO2 by microorganisms in water samples from three other lakes, but the pesticide was mineralized in sediment-containing water from two of those lakes. The results thus show that a pesticide may be cometabolized at one concentration or in samples from one type of environment and mineralized at a lower concentration or in samples from a different type of environment.

Shimp, Robert and Frederic K. Pfaender. 1985. Influence of Naturally Occurring Humic Acids on Biodegradation of Monosubstituted Phenols by Aquatic Bacteria. EPA/600/J-85/022. Appl. Environ. Microbiol. 49(2):402-407. (ERL,GB X493).

Samples of the microbial community from Lake Michie, a mesotrophic reservoir in central North Carolina, were adapted to various levels (100 to 1,000 ug/liter) of natural humic acids in chemostats. The humic acids were extracted from water samples from Black Lake, a highly colored lake in the coastal plain of North Carolina. After adaptation, the microbial community was tested for its ability to degrade the monosubstituted phenols m-cresol, m-aminophenol, and p-chlorophenol. Adaptation to increasing levels of humic acids significantly reduced the ability of the microbial communities to degrade all three phenols. The decline in biodegradation was accompanied by a decrease in the number of specific compound degraders in the adapted communities. Short-term exposure of the community to increasing levels of humic acids had no significant effect on the ability of the community to degrade m-cresol. Thus the suppressive effect of humic acids on monosubstituted phenol metabolism was the result of long-term exposure to the humic materials. Increasing the levels of inorganic nutrients fed to the chemostats during the humic acid adaptation had little effect on the suppressive influence of the humic acids, indicating that nutrient limitation was probably not responsible for the metabolic suppression. The results of the study suggest that long-term exposure to humic acids can reduce the ability of microbial communities to respond to monosubstituted phenols.

Shimp, Robert J. and Frederic K. Pfaender. 1985. Influence of Easily Degradable Naturally Occurring Carbon Substrates on Biodegradation of Monosubstituted Phenols by Aquatic Bacteria. EPA/600/J-85/023. Appl. Environ. Microbiol. 49(2):394-401. (ERL,GB X494).

The influence of readily degradable, naturally occurring carbon substrates on the biodegradation of several monosubstituted phenols (m-cresol, m-aminophenol, p-chlorophenol) was examined. The natural substrate classes used were amino acids, carbohydrates, and fatty acids. Samples of the microbial community from Lake Michie, a mesotrophic reservoir, were adapted to different levels of representatives from each natural substrate class in chemostats. After an extended adaptation period, the ability of the microbial community to degrade the monosubstituted phenols was determined by using a radiolabeled substrate uptake and mineralization method. Several microbiological characteristics of the communities were also measured. Adaptation to increasing concentrations of amino acids, carbohydrates, or fatty acids enhanced the ability of the microbial community to degrade all three phenols. The stimulation was largest for m-cresol and m-aminophenol. The mechanism responsible for the enhancement of monosubstituted phenol metabolism was not clearly identified, but the observation that adaptation to amino acids also increased the biodegradation of glucose and, to a lesser extent, naphthalene suggests a general stimulation of microbial metabolism. This study demonstrates that prior exposure to labile, natural substrates can significantly enhance the ability of aquatic microbial communities to respond to xenobiotics.

Llabres, Carlos M. and Donald G. Ahearn. 1985. Antimicrobial Activities of N-chloramines and Diazolidinyl Urea. EPA/600/J-85/019. Appl. Environ. Microbiol. 49(2):370-373. (ERL,GB X495).

A combination of MICs of an N-chloramine, a simple chlorinated amino acid, and diazolidinyl urea gave synergistic activity against bacteria, but not fungi. The two compounds at a higher concentration, 0.1 and 0.3 percent, respectively, gave synergistic inhibition of fungi; kill times were 1 h for Trichophyton tonsurans, 3 h for Aspergilus niger and Fusarium moniliforme, and 6 h for Aspergillus fumigatus.

Somerville, C.C., C.A. Monti and J.C. Spain. 1985. Modification of the 14C Most-Probable-Number Method for Use with Nonpolar and Volatile Substrates. EPA/600/J-85/021. Appl. Environ. Microbiol. 49(3):711-713. (ERL,GB X496).

A method was developed to allow the use of volatile and nonpolar substrates in 14C most-probable-number tests. Naphthalene or hexadecane was sorbed to filter paper disks and submerged in minimal medium. The procedure reduced the volatilization of the substrates while allowing them to remain available for microbial degradation.

Sullivan, Timothy J. and Michael C. Mix. 1985. Persistence and Fate of Polynuclear Aromatic Hydrocarbons Deposited on Slash Burn Sites in the Cascade Mountains and Coast Range of Oregon. EPA/600/J-85/034. Arch. Environ. Contam. Toxicol. 14:187-192. (ERL,GB X497).

The persistence of polynuclear aromatic hydrocarbons (PNAH) on slash burn sites and movement of these compounds between compartments of the sites has been investigated in the Cascade Mountains and Coast Range of Oregon. Phenanthrene and fluoranthene were gradually lost from the litter, reaching concentrations below detection limits (approximately 2g/ha) less than two years after burning. Higher molecular weight PNAH were more persistent in the litter, decreasing after five years approximately to 19-23 percent of initial deposition. Movement into the top 2 cm of the soil profile was more pronounced for the lower molecular weight PNAH, but all compounds appeared to equilibrate between litter and soil on the basis of organic content within one year after burning. Differential persistence and fate of PNAH on slash burn sites is explained by physical chemical characteristics of the compounds, such as solubility, vapor pressure, and octanol-water partition coefficient.

Hendricks, Jerry D., Theodore R. Meyers, Dennis W. Shelton, John L. Casteel and George S. Bailey. 1985. Hepatocarcinogenicity of Benzo[a]pyrene to Rainbow Trout by Dietary Exposure and Intraperitoneal Injection. EPA/600/J-85/053. J. Natl. Cancer Inst. 74(4):839-851. (ERL,GB X498).

The influence of benzo(a)pyrene on the induction of certain enzymes within the hepatic mixed-function oxidase (MFO) system and its potential carcinogenicity were examined in rainbow trout (Salmo gairdneri). Twelve months after BP exposure was initiated, 15 percent of the BP-fed fish had histologically confirmed neoplasms of the liver. After 18 months the incidence increased to 25 percent. No evidence of neoplasia was observed in control fish. BP injected intraperitoneally resulted in a 50 percent incidence of hepatocellular neoplasms and in a fibrosarcoma of the liver and papillary adenomas of the swim bladder in 1 fish. These results indicate that BP is a potent inducer of selected hepatic MFO enzymes and establish, for the first time, the hepatocarcinogenicity of BP in an aquatic species.

Madsen, E.L. and Martin Alexander. 1985. Effects of Chemical Speciation on the Mineralization of Organic Compounds by Microorganisms. EPA/600/J-85/147. Appl. Environ. Microbiol. 50(2):342-349. (ERL,GB X500). (Avail. from NTIS, Springfield, VA: PB86-101094)

The mineralization of 1.0 to 100 ng each of four complexing compounds--oxalate, citrate, nitrilotriacetate (NTA), and EDTA--per ml was tested in media prepared in accordance with equilibrium calculations by a computer program so that the H, Ca, Mg, Fe, or Al complex (chemical species) was predominant. Sewage microorganisms mineralized calcium citrate more rapidly than iron, aluminum, or hydrogen citrate more rapidly than iron, aluminum, or hydrogen citrate, and magnesium citrate was degraded slowest. Aluminum, hydrogen, and iron oxalates were mineralized more rapidly than calcium oxalate, and magnesium oxalate was decomposed slowest. Sewage microorganisms mineralized calcium NTA but not aluminum, magnesium, hydrogen, or iron NTA or any of the EDTA complexes. Pseudomonas sp. mineralized calcium and iron citrates but had no activity on hydrogen, aluminum, or magnesium citrate. Pseudomonas pseudoalcaligenes mineralized calcium, iron, hydrogen, and aluminum citrates but had little activity on magnesium citrate. Pseudomonas alcaligenes used calcium, iron, hydrogen, and aluminum oxalates readily, but it used magnesium oxalate at a slower rate. Listeria sp. destroyed calcium NTA but had no effect on hydrogen, iron, or magnesium NTA. Increasing the Ca concentration in the medium enhanced the breakdown of NTA by Listeria sp. The different activities of the bacterial isolates were not a result of the toxicity of the complexes or the lack of availability of a nutrient element. NTA mineralization was not enhanced by the addition of Ca to Beebe Lake water, but it was enhanced when Ca and an NTA-degrading inoculum were added to water from an oligotrophic lake. The data show that chemical speciation influences the mineralization of organic compounds by naturally occurring microbial communities and by individual bacterial populations.

Battalora, M.S.J., R.D. Ellender and B.J. Martin. 1985. Gnotobiotic Maintenance of Sheepshead Minnow Larvae. Prog. Fish-Cult. 47(2):122-125. (ERL,GB X502).

Gnotobiology is the study of animals in a microbial free environment. This provides an opportunity to examine the response of a host in a condition free of contamination, and how a defined relationship may affect nutritional requirements, immune resonses, and reactions to toxic chemicals. Excluding the work on the platyfish (Platypoecilus maculatus) and on salmonids, fish have received little attention in gnotobiotic research. This report expands the results of a previous study which concerned the gnotobiotic development of the sheepshead minnow, Cyprinodon variegatus.

Kendall, J.J., Jr., E.N. Powell, S.J. Connor, T.J. Bright and C.E. Zastrow. 1985. Effects of Turbidity on Calcification Rate, Protein Concentration and the Free Amino Acid Pool of the Coral Acropora cervicornis. EPA/600/J-85/151. Mar. Biol. (Berl.). 87(1):33-46. (ERL,GB X503). (Avail. from NTIS, Springfield, VA: PB86-101086)

Calcification rate in the coral Acropora cervicornis was reduced significantly when exposed for 24 h to 100-ppm kaolin, but was unchanged in corals exposed to 50-ppm kaolin. Calcification rate returned to control levels during a 48-h recovery period. Most free amino acids (FAA) in the FAA pool decreased significantly in corals exposed to 100-ppm kaolin, but were unchanged in corals exposed to 50-ppm kaolin. After a 48-h recovery period, the FAA pool remained considerably below control levels in the 100-ppm exposed corals and dropped below control levels in the 50-ppm exposed corals. Calcification rate dropped less and later during the exposure period in the growing tip than in sections further down the stalk. The reduction in FAA pool size was considerably larger in the growing tip than further down the stalk. Soluble protein concentration remained unchanged during both exposure and recovery. The data are consistent with the interpretation that turbidity not only causes a decrease in photosynthetic rate and the synthesis of small molecules, but also causes a large increase in the utilization of stored organic molecules for such metabolically costly processes as mucus production and sediment removal.

Connolly, John P. 1985. Predicting Single-Species Toxicity in Natural Water Systems. EPA/600/J-85/338. Environ. Toxicol. Chem. 4(4):573-582. (ERL,GB X505). (Avail. from NTIS, Springfield, VA: PB86-171618)

A methodology is proposed to predict single-species toxicity in natural waters by using laboratory bioassay data which relate effect to a tissue concentration of toxicant or to injury accumulation. Such relationships should be independent of test conditions and therefore transferable from lab to field. A mathematical model of uptake and elimination of toxicants by fish is used to relate exposure concentration to tissue concentration and then to effect. Prediction of toxicity in a laboratory test in which the exposure concentration varies in time is presented as a first step in testing the methodology. Survival time under time-varying exposure is calculated and compared to observed data. The model predicted survival times that were consistent with the observed times. Whole-body residue is used as the estimate of dose.

Connolly, John P. and Rosella Tonelli. 1985. Modelling Kepone in the Striped Bass Food Chain of the James River Estuary. EPA/600/J-85/175. Estuarine Coastal Shelf Sci. 20(3):349-366. (ERL,GB X506). (Avail. from NTIS, Springfield, VA: PB86-120201)

A mathematical model that computes the accumulation of Kepone in the striped bass food chain of the James River estuary was developed. The purpose of the model was to help understand the relationship of Kepone levels in important fish species to sediment and water column Kepone concentrations and then to address the question of why these levels still exceed Food and Drug Administration limits eight years after discharge ceased. The model considers exposure through diet and respiration at rates based on species bioenergetics. It was successfully calibrated to the Kepone concentrations observed in the period 1976 through 1982 in striped bass, white perch, and Atlantic croaker Kepone concentrations. The model indicates that for the upper levels of the food chain, diet is the major route of contamination, accounting for 87-88 percent of the observed concentration in croaker and white perch and 91 percent of the observed concentration in striped bass. The two Kepone sources; sediment and water column, contribute approximately equally to the croaker and white perch. The water column is more significant for striped bass, being the original source for approximately 60 percent of the observed body burdens. It was estimated that a criterion requiring Kepone concentrations in fish to be at or below 0.3 ug/g would require dissolved water column and sediment Kepone concentrations to be reduced to somewhere between 3 and 9 ng/l and 13-39 ng/g, respectively, depending on the species. Striped bass require the greatest reductions in dissolved water column and sediment Kepone concentrations to somewhere between 3 and 5 ng/l and 13 and 24 ng/g respectively.

Colwell, R.R., P.R. Brayton, D.J. Grimes, D.B. Roszak, S.A. Huq and L.M. Palmer. 1985. Viable but Non-Culturable Vibrio cholerae and Related Pathogens in the Environment: Implications for Release of Genetically Engineered Microorganisms. Bio/Technology. 3:817-820. (ERL,GB X524).

In a series of microcosm and field studies, we have observed that over time V. cholerae and related human pathogens enter a viable but non-culturable state. Direct viable counts by epifluorescent microscopy are consistently higher than corresponding plate counts. Thus, the assumption that microorganisms, including pathogens, 'die-off' or 'decay' in the marine environment must be re-evaluated, since stressed or nutrient starved cells are unable to grow and be enumerated by standard plate count methods. Furthermore, animal passage reveals pathogenicity persisting for such 'non-viable' cells. Indirect immunofluorescent microscopy offers a more sensitive detection system for environmental sampling for human pathogens and therefore, a more valid estimation of population size. One implication of these findings for the release of genetically engineered organisms is that highly specific methods of detection and monitoring are required, with direct detection by fluorescent antibody the most reliable at the present time.