Toxicological risk assessment in CO2 capture and storage technology

Abstract

Carbon dioxide capture and storage (CCS) is regarded as a powerful technology in mitigating the impacts of climate change and is considered as interim solution until other sustainable energy technologies can be used on a broader scale. Despite the fact that well conducted geological risk analyses exists, a major toxicological risk assessment including all components of the process is missing. Therefore, a literature study was undertaken with its focus on potential toxicological risks. These could appear in all parts of the CCS chain: in the capture process when chemicals are used for scrubbing, during transportation in case of accidents, and during geological storage when a leakage of CO2 or brine occurs. Toxicological hazards of special concern emerge not from CO2, but degradation products of scrubbing chemicals (nitrosamines and nitramines) or H2S-co-transportation. Additionally, contamination of potable aquifers due to mobilisation of hazardous trace elements, such as arsenic, nickel, and lead could become relevant in case of a leakage. Overall, to achieve further safety for the implementation of CCS as a mitigation technology, investigations in acute CO2-toxicity (with derivation of mass-intoxications threshold values), acute emergency management, and contaminants should be prime objectives for future CCS risk assessment research.