Christian Byrne

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.

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.

Survey of dioxin-like compounds in dairy feeds in the United States.

The United States Environmental Protection Agency (USEPA) has completed a survey of dioxin-like compounds (including 17 dioxin and furan (CDD/F) congeners and 12 coplanar polychlorinated biphenyl (PCBs) congeners) in dairy feeds from 10 dairy research facilities around the United States, sampling the overall mixtures and the major and minor feed components. Low levels of dioxin were found in all feed mixtures with an average concentration of 0.05 pg/g (ppt) toxic equivalent (TEQ) dry weight. This is lower than previously found in dairy feeds by about a factor of 4. While it is possible that generally lower levels of dioxins in the environment in recent years may explain this result, examinations of the data suggest that the oven drying used to prepare the wet feed samples could have resulted in a loss of dioxins from the feed materials. The percentage of the total TEQ due to CDD/Fs was about four times that of PCBs. Leafy vegetations in the feed (the silages and the hays) had concentrations about twice as high as nonleafy, protected vegetation of the feeds (the ground or meal corn, cottonseed, and others). Minor components did not significantly influence the final feed mixture concentration of dioxin TEQ. However, in one of the feed mixtures, a minor component with a high concentration of 38.5 ppt TEQ effectively doubled the concentration of the overall feed mixture.

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.

Per- and polyfluoroalkyl substances in source and treated drinking waters of the United States

Contaminants of emerging concern (CECs), including per- and polyfluoroalkyl substances (PFAS), are of interest to regulators, water treatment utilities, the general public and scientists. This study measured 17 PFAS in source and treated water from 25 drinking water treatment plants (DWTPs) as part of a broader study of CECs in drinking water across the United States. PFAS were quantitatively detected in all 50 samples, with summed concentrations of the 17 PFAS ranging from <1 ng/L to 1102 ng/L. The median total PFAS concentration was 21.4 ng/L in the source water and 19.5 ng/L in the treated drinking water. Comparing the total PFAS concentration in source and treated water at each location, only five locations demonstrated statistically significant differences (i.e. P < 0.05) between the source and treated water. When the perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) concentrations in the treated drinking water are compared to the existing US Environmental Protection Agency’s PFOA and PFOS drinking water heath advisory of 70 ng/L for each chemical or their sum one DWTP exceeded the threshold. Six of the 25 DWTPs were along twolarge rivers. The DWTPswithin each of the river systems had specific PFAS profiles, with the three DWTPs from one river being dominated by PFOA, while three DWTPs on the second river were dominated by perfluorobutyric acid (PFBA).