Higher levels of persistent pollutants (Σ16PCB, Σ6PBDE, ΣHCH, ΣDDT, ΣCHL) were detected in fresh eggs of Common Terns Sterna hirundo from Rockabill Island near Dublin (Ireland's industrialised capital city) compared to Common and Arctic Terns S. paradisaea from Ireland's west coast. Intra-clutch variation of pollutant levels in Common Terns was shown to be low, providing further evidence that random sampling of one egg may be an appropriate sampling strategy. Significant differences in pollutant concentrations were detected between fresh and abandoned eggs on Rockabill. However, abandoned eggs can still provide a useful approximation of pollutants in bird eggs if non-destructive sampling is preferred. Levels of p,p’ –DDE in tern eggs have decreased over time according to this study, in concurrence with worldwide trends. Results in this study fall below toxicological thresholds for birds and OSPARs EcoQO thresholds set for Common Tern eggs, except for mercury and HCH in the west coast.

持久性有机污染物（水平较高Σ 16PCB，Σ 6PBDE，Σ六六六，Σ DDT，Σ在普通燕鸥的鲜鸡蛋检测CHL）燕鸥比较常见和北极燕鸥都柏林（爱尔兰的工业化首府）附近，距Rockabill岛S.天堂来自爱尔兰的西海岸。事实表明，普通燕鸥的离合器内污染物水平变化很小，这提供了进一步的证据表明，对一个鸡蛋进行随机采样可能是一种合适的采样策略。在Rockabill上，新鲜鸡蛋和废弃鸡蛋之间的污染物浓度存在显着差异。但是，如果首选非破坏性采样，则废弃的鸡蛋仍可以提供禽蛋中污染物的有用近似值。这项研究表明，随着时间的推移，燕鸥卵中p， p'–DDE的水平随着时间的推移而下降。这项研究的结果低于鸟类的毒理学阈值和普通燕鸥卵的OSPARs EcoQO阈值，西海岸的汞和六氯环己烷除外。