Sea turtles are exposed to, and accumulate, chemical contaminants from the marine environment. Cell-based techniques have increasingly been applied to sea turtles to better assess the effects of these contaminants. These techniques can be used to assess the effects of environmentally relevant mixtures and concentrations of organic contaminants to which turtles are exposed by extracting contaminants from turtle blood and testing the toxicity of extracts on sea turtle cells. This technique was used to assess spatial and temporal changes in chemical exposure and effect in foraging sea turtle populations throughout Queensland. Differences in chemical exposure between foraging grounds were detected, highlighting foraging populations that may be at greater risk. Temporal changes in chemical exposure were also detected in an industrialised seaport, with significant increases in exposure over time. Importantly, these results also include a measure of effect, providing more information than chemical analysis alone. These results demonstrate this technique can be applied to regular monitoring of chemical contaminants and highlight the importance of ongoing monitoring to comprehensively assess chemical risk in sea turtles.