• Application of congener based multi-matrix profiling techniques to identify potential PCDD/F sources in environmental samples from the Burrishoole Catchment in the West of Ireland

      White, P.; McHugh, B.; Poole, R.; McGovern, E.; White, J.; Behan, P.; Foley, B.; Covaci, A. (Elsevier, 2014)
      Homologue and congener profiles of PCDD/Fs in eels, passive sampler and sediment extracts from the Burrishoole, a rural upland catchment on the western Irish seaboard were compared with potential PCDD sources. ΣPCDD/F levels in eels ranged from 2.9 to 25.9 pg g−1 wet weight, which are elevated compared to other Irish locations. The OCDD congener dominated the pattern of ΣPCDD/Fs in all matrices from Burrishoole. Passive samplers were successfully deployed to identify for the first time the presence in the water column of PCDD/Fs and dimethoxylated octachlorodiphenyl ether (diMeOoctaCDE), impurities found in pentachlorophenol (PCP) production. Principal component analysis (PCA) identified similarities between PCDD/F profiles in technical PCP mixtures and environmental samples from the Burrishoole region. Results strongly suggest residual PCDD contamination associated with historic local use of a dioxin contaminated product in the catchment area, with pentachlorophenol a strong candidate.
    • Utilising caging techniques to investigate metal assimilation in Nucella lapillus, Mytilus edulis and Crassostrea gigas at three Irish coastal locations

      Giltrap, M.; Macken, A.; Davoren, M.; McGovern, E.; Foley, B.; Larsen, M.; White, J.; McHugh, B. (Elsevier, 2013)
      Pollution by metals has been of increasing concern for a number of decades but at present, the mechanism of metal accumulation in sentinel species is not fully understood and further studies are required for environmental risk assessment of metals in aquatic environments. The use of caging techniques has proven to be useful for assessment of water quality in coastal and estuarine environments. This study investigates the application of caging techniques for monitoring uptake of 20 elements [Li, Na, Mg, Al, P, K, Ca, V, Cr, Mn, Fe, Ni, Co, Cu, As, Sb, Pb, Hg, Cd and Zn] in three marine species namely Nucella lapillus, Mytilus edulis and Crassostrea gigas. Stable isotopes were used to determine predatory effects and also used for modelling metal uptake in test species and to track nutrient assimilation. Metal levels were monitored at three different coastal locations, namely Dublin Bay, Dunmore East and Omey Island over 18 weeks. Significant differences in concentrations of Mn, Co and Zn between mussels and oysters were found. Correlations between cadmium levels in N. lapillus and δ13C and δ15N suggest dietary influences in Cd uptake. Levels of Zn were highest in C. gigas compared to the other two species and levels of Zn were most elevated at the Dunmore East site. Copper levels were more elevated in all test species at both Dublin Bay and Dunmore East. Mercury was raised in all species at Dunmore East compared to the other two sites. Biotic accumulation of metals in the test species demonstrates that caging techniques can provide a valid tool for biomonitoring in metal impacted areas.