Robert D. Stephens

Determination of aromatic sulfonic acids in aqueous environmental samples by anion-exchange chromatography coupled to particle beam mass spectrometry and UV spectrophotometry

Abstract Aromatic sulfonic acids are determined in water using anion-exchange liquid chromatography. Quantification is by UV absorption spectrophotometry (quantification limits 2–80 ng on-column) and confirmation by particle beam electron impact ionization mass spectrometry. Separations with several anion-exchange columns using acetonitrile and ammonium acetate or sodium hydroxide (requiring a membrane suppressor for desalting) mobile phases are represented. Average recoveries are 82% for six monosulfonic acids (spiked at 0.1, 1.0 and 100 ppm) and 95% for two disulfonic acids (spiked at 1.0 and 100 ppm) (S.D. 12%, UV quantification). Mass spectra (2.0 μg on-column) show molecular and major diagnostic fragment ions corresponding to losses of SO 2 HSO 2 , SO 3 and HSO 3 .

Foraging fram animals as biomonitors for dioxin contamination

Abstract Studies carried out in California, following a fire which involved a pentachlorophenol wood treatment plant have indicated that low concentrations of dioxins and furans in soil can lead to bioaccumulation in chickens and cattle which are in contact with the soil. These compounds were found to distribute into various tissues of the animals and into the eggs of the chickens. A significant change in congener profile and isomer pattern was seen when comparing soils to tissues. Source tests of local incinerators showed quite different congener profile than was seen in soils. Concentrations found in animal products used as food suggest the possibility of excessive human exposure based on modest consumption assumptions.

Biotransfer and bioaccumulation of PCDD/PCDFs from soil: Controlled exposure studies of chickens

Abstract Controlled exposure studies under laboratory and field conditions have been initiated to investigate the biotransfer and bioaccumulation of PCDD/Fs in soil, at low concentrations, to animals which have contact with soil. The chicken was chosen as a model for grazing animals. The accumulation over time of specific isomers is being tracked in eggs, blood, feces, liver, adipose, and edible flesh. Measurable increases of PCDD/F concentration in eggs of exposed chickens, as compared to controls, were seen after 30 days of exposure. The exposure characterization, as well as data on isomer specific biotransfer and bioaccumulation rates in eggs are discussed.

Bioaccumulation of PCDDs and PCDFs in food animals III: A rapid cleanup of biological materials using reverse phase adsorbent columns

Abstract This study describes a simple, rapid and cost effective analytical technique for the ultratrace analysis of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in biological samples. Solid Phase Extraction (SPE) techniques using disposable C-18 bonded silica column for dioxin enrichment have been investigated. The procedures used for extraction of PCDD/F from animal tissues and blood plasma are described. Spiked recoveries of surrogates from eggs, livers, birds and blood plasma are reported. The suitability of SPE for the determination of PCDD/F is demonstrated by the analysis of contaminated biological samples. Comparison of results obtained from the SPE method and from the traditional sulfuric acid cleanup is presented.

Aquatic life as biomonitors of dioxin/furan and coplanar polychlorinated biphenyl contamination in the Sacramento-San Joaquin river delta

Abstract A pilot study was designed to investigate the extent, magnitude and source of polychlorinated dibenzodioxin and furan (PCDD/F) and coplanar polychlorinated biphenyl (PCB) contamination using aquatic life as biomonitors. The study focused around a bleached pulp and paper mill operating, along with other industrial facilities, near the confluence of the Sacramento and San Joaquin rivers (Delta) in northern California. Four locations were selected for sampling: two upstream from the plant (one on each river), one in the vicinity of the plant and one downstream from the plant. Because of the salinity gradient of the riverine system, no single fish or bivalve species could be collected, but multiple comparisons were made instead. The target species were selected on the basis of their abundance and localized feeding range. Clams were transplanted in the three freshwater locations and retrieved two months later, while resident mussels were collected from the estuarine location. Surface sediment samples were collected from each location. Whole body fish samples were composited or analysed individually based on size. The samples were freezedried, cleaned by a modified Smith-Stalling procedure, and the coplanar PCBs and PCDD/Fs were isolated and analysed by HRGC/HRMS. Low levels of PCDD/Fs were found in all samples: 1–3 pg/g TEQ (wet wt) in fish; 1–5 pg/g I-TEQ (dry wt) in bivalves; and from 3–51 pg/g I-TEQ (dry wt) in sediments with variable PCB levels. With few exceptions, only 2,3,7,8-substituted PCDD/Fs were found in fish, whereas bivalves had both 2,3,7,8-substituted and non-2,3,7,8-substituted PCDD/Fs with relatively high levels of total TCDDs compared to total PeCDD or HxCDD. Sediments had a PCDD/F pattern consistent with pentachlorophenol contamination. Comparison of sediments and collocated bivalves did not indicate bioconcentration in PCDD/Fs, but it did reveal a tenfold increase in PCB #77 and #126. Within each sample type, the PCDD/F and PCB congener profiles were consistent across species and locations. Shifts in congener profiles from sediments to bivalves to fish were consistent across locations. From the available data, the influence of the pulp mill, if any, could not be distinguished from the other sources in the region.

Speciation and quantitation of Aroclors in hazardous wastes based on PCB congener data

Abstract Selected chlorobiphenyl congener data were used to accurately estimate the Aroclor content of hazardous wastes. Only 12 chlorobiphenyl congeners are determined nominally, IUPAC Nos. 15, 18, 31, 87, 105, 110, 118, 170, 180, 183, 203 and 206, and from these marker compounds Aroclors 1016, 1254, 1260 and 1268 are estimated. The remaining regulated Aroclor mixtures also are measured by this technique making it suitable for enforcement of existing California and U. S. regulations. An additional 34 chlorobiphenyl congeners are routinely analyzed allowing determination of PCBs in highly weathered and/or treated wastes. Included are the major constituents of the commercial Aroclors and the predominant congeners in the environment. The sum of PCB congener concentrations, “s-PCB”, is generally about 70% of the total Aroclor content. The use of capillary column separations and data reduction procedures described has a number of advantages over packed column GC procedures: 1) data interpretation does not require analyst judgement and can be automated; 2) the techique makes full use of the separation power of capillary columns to minimize interference by pesticides and other sample components; and 3) the technique accurately measures PCBs in samples with more than one Aroclor. Application of this technique to the determination of Aroclors in auto shredder waste is described and results compared to a packed-column procedure, U. S. EPA method 8080.

PCDD and PCDF in breast milk as correlated with fish consumption in Southern California

Abstract PCDD and PCDF levels were monitored in human milk obtained through the Women, Infants and Children Program of the Los Angeles County Public Health Department. The milk samples were from three groups with different fresh fish consumption. Only 2,3,7,8-substituted PCDD and PCDF isomers were detected in human milk at levels comparable to those previously reported in other regions of the world. PCDD and PCDF levels could not be used to distinguish the dietary groups. However, the Southern California and Swedish human milk analyzed by our methods could be distinguished form each other. The level of 2,3,4,7,8 PeCDF was 3 to 4 times lower in human milk from Southern California than in Swedish milk. Additionally, chlorinated naphthalenes were detected in both Swedish and California human milk at levels estimated to be 10 to 100 times that of the PCDDs and PCDFs.

Serum, adipose and autopsy tissue PCDD and PCDF levels in people eating dioxin contaminated beef and chicken eggs

Abstract We studied dioxin levels in residents of two California households where dioxin contaminated homegrown eggs and beef were found, in order to determine the level of exposure to dioxins. Risk assessments for carcinogenicity and reproductive toxicity showed that theoretical risks exceeded proscribed regulatory levels. Advisory guidelines were issued about consumption of eggs, chicken and beef. Serum samples from exposed and matched rural comparison subjects were analyzed and preliminary dioxin data show statistically significant elevations of 2,3,7,8-penta and hexa dioxin isomers for both homes. Comparison subjects from rural California had lower serum dioxin levels than those previously reported for Missouri and Sweden. Adipose tissue from a resident of one of the homes was tested for dioxins. The resident died six months later and a post mortem retesting of adipose and testing of liver and lung tissues for dioxins was done. No unusual dioxin levels were found; levels of dioxin in adipose remained stable despite six months of not eating contaminated produce. Dioxins were not a contributing cause of death. In this study, dioxin contaminated eggs and beef have elevated 2,3,7,8-tetra, penta and hexa dioxin levels in serum. The ongoing investigation will seek to delineate the source and extent of contamination, and to determine the extent of the exposed population and potential health impacts.

A MULTIMEDIA STUDY OF HAZARDOUS WASTE LANDFILL GAS MIGRATION

Hazardous waste landfills pose uniquely challenging environmental problems which arise as a result of the chemical complexity of waste sites, their involvement of many environmental media, and their very size and volume. Chemical substances of every description have or could be found at a typical hazardous waste landfill. These substances would represent the full range of physical and chemical properties, from inert to reactive, from nonvolatile to highly volatile, and from ionic, water miscible to nonpolar, hydrophobic compounds. Given this range of physico-chemical properties, and that landfills are earth containment facilities, there is the probability that all environmental compartments, air, water (surface and ground), soil, and biota will be involved. The additional factor which complicates the understanding of landfills is their size and volume. Although for certain purposes landfills can be considered quasi-point sources, in reality they are generally large and often situated in several different geological and hydrogeological regimes. The actual volume or mass of material existing at a landfill makes clear definition of its chemistry impractical.

Assessing the risks from 2,3,7,8 TCDD and TCDF in milk packaged in paper

Abstract PCDD and PCDF measurements were made on selected retail milk products, including paper packaged milk samples, covering all known paper carton suppliers in the state of California during 1989. Significant levels of 2,3,7,8 tetrachlorodibenzofuran (TCDF) and 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) were found in the paper packaged milk in all brands investigated except one. All other 2,3,7,8 substituted PCDFs and PCDDs were either not detected or detected at very low levels. Two non 2,3,7,8 substituted TCDFs were consistently detected in the contaminated milk samples. Using the mean concentration of 2,3,7,8 TCDF and TCDD detected and assuming a 480 ml daily consumption of milk for an adult, we estimated that the milk represented an additional 2.3 pg/kg/day of TCDD equivalent exposure based on the California toxic equivalence (CA TE), but only a 0.56 pg/kg/day increase using the International TE (ITE). The lifetime cancer risk was calculated to be 470 10 6 (CA TE) and 80 10 6 (ITE). Monitoring of retail milk products continued during 1990 but 2,3,7,8 TCDD and 2,3,7,8 TCDF were either not detected or detected at very low levels in all products investigated.