Date of Award

12-2005

Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Ecology and Environmental Sciences

Advisor

Howard H. Patterson

Second Committee Member

Aria Amirbahman

Third Committee Member

David Courtemanch

Abstract

Dioxin consists of a toxic group of compounds linked to harmful effects in human health such as suppression of the immune system and cancer (USEPA, 2004b). The Maine legislature enacted a law stipulating that effective December 31, 2002, dioxin concentration in fish upstream (or above) a paper mill is not to exceed the concentration downstream or below the mill (38 M.R.S.A. 420-A).

Since 1999, the Maine Dioxin Monitoring Program introduced the use of Semipermeable Membrane Device (SPMD) as a surrogate to fish sampling to perform the so-called above /below (AIB) test. This research project used the SPNID for monitoring dioxin levels above and below the International Paper Mill in Jay in order to perform the A43 test, and improve previous SPMD studies.

In September 2003, eighty SPMDS were deployed upstream (site ARY) and downstream of the mill (sites ASN, ALV, ALF). After retrieval, the SPMDs were dialyzed and the analytes quantified by HRGC/HRMS according to the USEPA method 1613B.

The permeability reference compound-corrected water concentration estimates vary from 0.005 pg/L for 2,3,7,8-TCDF (at ALV) to 0.098 pg/L for OCDD (at ARY). The Kruskal Wallis (statistical) test yielded higher equal- or higher- dioxin concentrations in SPMDs above the mill (ARY) than below the mill. These results showed that, during the sampling period, the mill in Jay was in compliance with the 1997 dioxin law. Suggestions are made for a better understanding of dioxin fate and transport in the different phases of the environmental system, especially the characterization of the sources of PCDD input in the river.

Dioxin is not the only waterborne pollutant of concern in Maine. Atlantic salmon (Salmo solar) habitat in Downeast Rivers is threatened by pesticide contamination derived from blueberry (Vaccinium angustifolium) cultivation. In summer 2004, the Polar Organic Chemical Integrative Sampler (POCIS) was deployed at four streams in Washington and Hancock Counties in order to develop an alternative to grab sampling for these pesticides.

At each stream, four replicates comprising two POCIS each were deployed during 28 days in July 2004. After retrieval, the device admixture was extracted in organic solvents and the pesticides were quantified by GCIMS. Some pesticides such as chlorothalonil and propiconazole were not detected at any site. Terbacil was detected at only one sampling point at Pork Brook. Mean water concentration estimates for phosmet ranged from 0.56 ng/L (at Pork Brook) to 1.87 ng/L (at Bog Brook), and from non-detect to 481.65 ng/L (at Pleasant River) for hexazinone. The Kruskal Wallis test showed no statistically significant differences between sites for phosmet (p = 0.850). Hexazinone concentrations were the highest at Pleasant River, equal at Pork Brook and Bog Brook, and the lowest at Pleasant River Lake (p = 0.0007).

Despite some uncertainties related to the sampling rates used in the calculations of pesticide concentrations in water and some analytical problems with phosmet, the overall results show a promising opportunity of using the POCIS device to monitor the pesticides used on the blueberry fields in Washington and Hancock Counties.

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