Ildefonso R. DeLeon

Environmentally Significant Volatile Organic Pollutants in Human Blood

Volatile organic compounds are an important category of commercial and industrial chemicals whose common and frequent usage has rendered them ubiquitous in the environment. The occurrence of these chemicals as environmental pollutants, as well as their potentially toxic nature, has prompted numerous studies aimed at determining their presence and impact on the environment and on human health. To characterize and measure environmentally significant volatile organic pollutants in various sample matrices, the authors were interested in determining whether these chemicals were present in a patient population whose medical histories suggested a high sensitivity to synthetic chemicals. A second objective was to establish baseline concentration and frequency of occurrence data for six aromatic hydrocarbons and twelve halogenated organics in a selected population. Therefore, the authors undertook to ascertain the presence of eighteen commonly used organic solvents and vapors in whole blood of environmentally sensitive patients by means of a recently developed clinical screening test known as the VOST (volatile organics screening test).

Trace organic and heavy metal pollutants in the Mississippi River

Abstract A study was conducted to characterize and measure organic and heavy metal pollutants in the Mississippi River. Water samples were collected along the entire length of the river, and were screened for semivolatile organics by capillary GC and for heavy metals by atomic absorption spectrophotometry. Four water samples were further examined for semivolatile organics by capillary GC/MS. Eight heavy metals and more than sixty distinct organic chemicals were identified including alkylbenzenes, various halogenated organics, five herbicides or derivatives, plasticizers, polynuclear aromatic hydrocarbons (PAHs), saturated hydrocarbons, and three miscellaneous organics. All organic compounds were detected at the parts-per-trillion (pptr) level. In spite of the limited nature of the sampling effort, the large number of data derived from this study suggests the need for a more rigorous monitoring of the river for a wide spectrum of chemical pollutants.

Organics in the water column of Llake Pontchartrain

Abstract A study was conducted to quantitatively screen the Inner Harbor Navigation Canal of Lake Pontchartrain for the presence of EPA priority pollutants and any other pollutants detected in significant concentration. Water column samples were collected at different depths and on the flood and ebb tides. Compounds identified include aliphatic and aromatic hydrocarbons, phthlates, phenols, alcohols, amines, pesticides, herbicides, aldehydes, quinolines, fatty acids, carboxylic acids. These compounds were detected at the parts-per-trillion level. The concentrations of the individual organics detected on the flood and ebb tides were not significantly different. The data derived from samples taken at two different depths suggest that the distribution of organics in the water column was homogeneous.

Bioaccumulation of polynuclear aromatic hydrocarbons by the clam,Rangia cuneata, in the vicinity of a creosote spill

During 1980-81, as part of NOAA/US Coast Guard initiative, the authors participated in an environmental study of a creosote spill into Bayou Bonfouca at the American Creosote Works Plant (ACWP) site at Slidell, Louisiana. The objectives for the study were: (1) to determined the nature and extent of creosote contamination at the site and in the bayou, and (2) to evaluate through biomonitoring the bioavailability and human health implications of creosote derived PAHs in the bayou and the estuarine system into which Bayou Bonfouca flows. So dramatic were their findings that their data was used in part by state and federal agencies to bring about in 1982, the inclusion of the Bayou Bonfouca site on the National Priorities List of hazardous waste sites that pose a threat to public health and the environment. This is a report of their findings on the biomonitoring of their study.

Trace metal residues in biota and sediments from Lake Pontchartrain, Louisiana

As part of the continuing studies to characterize and identify chemical pollutants in natural bodies of water and as part of a preliminary study of the nutrient and toxic substances chemistry for the three passes into Lake Pontchartrain, the present study was conducted to establish baseline values to twelve USEPA priority pollutant trace metals in indigenous biota and sediment samples from the three passes of Lake Pontchartrain. The twelve metals included arsenic, beryllium, copper, cadmium, lead, mercury, nickel, thallium, selenium, chromium, silver, and zinc.

Base-neutral extractable organic pollutants in biota and sediments from Lake Pontchartrain

Abstract A study was conducted to screen the three passes that link Lake Pontchartrain to the Gulf of Mexico via Lake Borne for the presence of EPA base-neutral (BN) priority pollutants and any other pollutants detected in significant concentration. Biota and sediment samples were collected and analytical procedures were developed for the trace analysis of BN organics in these matrices. Compounds identified include alkanes (normal, branched, cyclic), alkenes, aromatics, alkylated aromatics, polynuclear aromatic hydrocarbons and their alkylated derivatives, phthalates, ketones, furans, thiophenes, phenols, amines, nitriles, thiazoles, amides, aldehydes, alcohols, free fatty acids, fatty acid methyl and ethyl esters, phosphates, sterols. Concentrations were in the parts-per-billion range.

Evidence for toxic anthropogenic chemicals in human thrombogenic coronary plaques

Thrombogenic coronary plaques are characteristic lesions associated with the pathogenesis of arteriosclerosis and result from the progressive degeneration in the structure of the intima of the large elastic blood vessels. This disease accounts for nearly half of all human deaths in advanced industrial societies.Since the necrotic core of an atherosclerotic plaque is a stationary mass rich in cholesterol and other associated lipids, man-made lipid-soluble pollutants could therefore be expected to partition from the aqueous blood into the oily phase of the plaque core. Such partitioning is widespread in nature and is exemplified by the presence of toxic environmental chemicals such as the organochlorine pesticides and polynuclear aromatics in hydrophobic biological systems of both aquatic and terrestrial organisms. Once accumulated, their toxicity is due to their subsequent binding to cellular macromolecules and the resultant alteration of the subcellular process to which they are involved. In theory, these toxic materials in the plaque could modify the activity of cholesterol secretion and/or metabolism or inhibit the bodys normal protective mechanisms thus initiating thrombogenesis and the accompanying pathologic morphology.To test this hypothesis, plaque gruel from the aortas of heart attack victims were mechanically dissected from the aortas of autopsied human subjects and analyzed for the presence of toxic compounds by sequential gas chromatography/mass spectrometry (GC/MS).

Bioaccumulation of chemical markers as a means for the field detection and verification of organophosphorus warfare agents.

This study investigates the viability of using common bivalve mollusks as bioaccumulators of marker compounds that can be used to verify the production or use of chemical warfare agents (CWAs). The bioaccumulation of synthetic contaminants in bivalve mollusks and other aquatic organisms is a widespread phenomenon, and the analysis of resident biota is an effective means of detecting and verifying the presence of contaminants and possibly identifying their anthropogenic source. The study reported in this paper demonstrates that detection and verification of the presence of CWAs (specifically, nerve agents VX and GB/Sarin) may be accomplished by a technique that measures the bioaccumulation of marker compounds in brackish-water clams

Contributions of heavy metals from municipal runoff to the sediments of Lake Pontchartrain, Louisiana

Abstract A study was conducted to determine the distribution and sources of heavy metal pollutants in the sediments of Lake Pontchartrain. Sediment samples were collected from the northern and southern shorelines and analyzed for heavy metals by atomic absorption spectrometry. The heavy metals of interest were barium, copper, nickel, lead, and zinc. The concentrations of these metals indicate that the principal source of heavy metal pollution is associated with urban stormwater runoff and municipal discharges.

THE ROLE OF ANALYTICAL CHEMISTRY IN A TOXIC SUBSTANCE SPILL INTO THE AQUATIC ENVIRONMENT

ABSTRACT On July 22, 1980, a major chemical spill occurred 40 miles southeast of New Orleans in the Mississippi River Gulf Outlet (MRGO), a man-made deep draft channel connecting the Port of New Orleans with the Gulf of Mexico. The spill resulted from the collision of a containerized cargo vessel (M/V TESTBANK) with a bulk ore carrier (M/V SEA DANIEL). Large quantities of technical grade pentachlorophenol (PCP), hydrobromic acid, vinyl polymer, as well as other items of the containerized cargo were lost into the 35-ft deep channel. Ruptured drums released ethyl mercaptan into the atmosphere. An estimated 12 tons of toxic PCP were lost into the estuarine environment immediately adjacent to major shrimp fisheries and oyster beds. The Center for Bio-Organic Studies of the University of New Orleans assisted in the design and implementation of a multiphase analytical chemistry support program to complement the response efforts by federal and state agencies. The program was designed to assist in locating the bulk of spilled PCP and to monitor the distribution and movement throughout the environment of PCP and its major metabolites and production-related impurities. Latter stages of the program involved monitoring the effectiveness of cleanup activities and the short-term impact of the PCP on the environment. Over 300 water, sediment and biota samples were collected and analyzed. The exposure to PCP of response and cleanup workers was monitored by the analysis of approximately 200 blood and urine samples. Existing analytical methods were refined to meet the special requirements of the spill situation. In order to assist participating state and federal agencies, an interlaboratory calibration program was also established. The activities of our laboratory during this incident, and the importance of a broad but flexible analytical chemistry support program to complement the response organizations efforts during a toxic chemical spill are discussed.