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An investigation was conducted into the likely impacts of exploratory drilling to coral and sponge species in the Newfoundland and Labrador (NL) region, as well as the ways in which avoidance and mitigation measures can be applied to reduce them. Impacts described in existing literature suggest that coral and sponge species may experience changes in behaviour (e.g. feeding, reproduction), fitness, and survival as a result of physical damage, exposure to chemicals, and/or excess sedimentation which result from exploratory drilling activities. As outlined in the Fisheries Act, it is recommended that a "mitigation hierarchy" of: (1) avoid, (2) mitigate, (3) offset, be used to reduce risks to biodiversity. However, because offsetting impacts would not generally be compatible with benthic conservation objectives, they are not discussed in depth in this report. Following this hierarchy, the avoidance of exploratory drilling in existing special areas that have been previously delineated based on the presence of coral and/or sponge species in high densities is essential for preserving biodiversity in the region. This would include Significant Benthic Areas (SiBAs), Vulnerable Marine Ecosystems (VMEs), and any sites where the zone of influence from exploratory drilling would overlap SiBA or VME boundaries. Avoidance in areas outside SiBAs and VMEs where the density of coral and sponge species observed during pre-drill surveys meets the thresholds used to define SiBAs and VMEs is also of high importance. In addition, various modifications to existing exploratory drilling processes, intended to mitigate the impacts to coral and sponge species, without considerations to engineering and/or economic impacts, have also been outlined within the report. They would allow for reductions to the area of impact, the amount of cuttings generated, and the release of drilling muds into the environment, thereby reducing the overall impact to coral and sponge species in the area. [ABSTRACT FROM AUTHOR]

Dendritic cells' (DC) activation is considered a key event in the adverse outcome pathway for skin sensitization elicited by covalent binding of chemicals to proteins. The mechanisms underlying DC activation by contact sensitizers are not completely understood. However, several "danger signals" are pointed as relevant effectors. Among these extra-cellular early danger signals, purines may be crucial for the development of xenoinflammation and several reports indicate their involvement in contact allergic reactions. In the present work we used the DC-surrogate monocytic cell line THP-1, cultured alone or co-cultured with the human keratinocyte cell line HaCaT, to explore the contribution of extracellular adenine nucleotides to THP-1 maturation triggered by the extreme contact sensitizer, 1-fluoro-2,4-dinitrobenzene (DNFB). We found that THP-1 maturation induced by DNFB is impaired after purinergic signaling inhibition, and that the transcription of the purinergic metabotropic receptors P2Y2 and P2Y11 is modulated by the sensitizer. We also detected that THP-1 cells only partially hydrolyse extracellular adenosine triphosphate, leading to accumulation of the mono-phosphate derivative, AMP. We detected different and non-overlapping activation patterns of mitogen activated protein kinases by DNFB and extracellular nucleotides. Overall, our results indicate that THP-1 maturation induced by DNFB is strongly modulated by extracellular adenine nucleotides through metabotropic purinergic receptors. This knowledge unveils a molecular toxicity pathway evoked by sensitizers and involved in THP-1 maturation, a DC-surrogate cell line thoroughly used in in vitro tests for the identification of skin allergens. [ABSTRACT FROM AUTHOR]