Gadolinium-uptake by aquatic and terrestrial organisms-distribution determined by laser ablation inductively coupled plasma mass spectrometry

Abstract

Gadolinium (Gd) based contrast agents (CA) are used to enhance magnetic resonance imaging. As a consequence of excretion by patients and insufficient elimination in wastewater treatment plants they are detected in high concentrations in surface water. At present, little is known about the uptake of these species by living organisms in aquatic systems. Therefore the uptake of gadolinium containing chelates by plants and animals grown in exposed water or on soil irrigated with exposed water was investigated. For this purpose two types of plants were treated with two different contrast agents. The uptake of the Gd contrast agents was studied by monitoring the elemental distribution with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). This technique allows the multi-elemental analysis of solid samples with high resolution and little sample preparation. The analysis of L. minor showed that the uptake of Gd correlated with the concentration of gadodiamide in the water. The higher the concentration in the exposed water, the larger the Gd signal in the LA-ICP-MS acquired image. Exposure time experiments showed saturation within one day. The L. minor had contact with the CAs through roots and fronds, whereas the L. sativum only showed uptake through the roots. These results show that an external absorption of the CA through the leaves of L. sativum was impossible. All the analyzed parts of the plant showed Gd signal from the CA; the highest being at the main vein of the leaf. It is shown that the CAs can be taken up from plants. Furthermore, the uptake and distribution of Gd in Daphnia magna were shown. The exposure via cultivation medium is followed by Gd signals on the skin and in the area of the intestine, while the uptake via exposed nutrition algae causes the significantly highest Gd intensities in the area of the intestine. Because there are hints of negative effects for human organism these findings are important as they show that Gd based CAs may reach the human food chain via plants and animals growing in contaminated water or plants growing in fields which are irrigated with surface water.

Detection and imaging of gadolinium accumulation in human bone tissue by micro- and submicro-XRF

“…In the recent years the anthropogenic Gd pollution, especially in aquatic systems, became a topic of extensive research [33][34][35] . However, we doubt that the low concentrations of Gd in tap water could lead to the found accumulation in bone tissue; and given the likely subject's occupational history, the likelihood of presumable occupational exposure to elevated concentrations of gadolinium is remote.…”

Assessment of the toxic effects of mixtures of three lanthanides (Ce, Gd, Lu) to aquatic biota

“…were first joined to the algae added as food, and therefore light REEs could have greater toxic effect by direct uptake from the media. On the other hand, Lingott et al (2016), in an experiment with daphnids exposed to Gd, suggested a greater Gd content related by algae ingestion added as food. Although LN-uptake routes for the rotifer should be further studied for a better interpretation of the obtained effect, these previous results indicated that the addition of algae as food could modify the availability of LN for the organisms and therefore results should be interpreted carefully.…”

“…The observed decrease in LN concentration was directly correlated with time exposure, and LN precipitation seems to take place at the start of the tests with a high decline of the LN amount remaining in the solution (Figure SI-3). Differences between measured concentrations at the beginning and at the end of the tests ( , therefore free ions often account for a small portion in natural water, although they have generally been found as the main predictors of LN toxicity (Tan et al, 2017;Lingott et al, 2016).…”

Are the increasing amounts of gadolinium in surface and tap water dangerous?

“…Another important topic is how the fields irrigated by contaminated water and the animals drinking it are affected, since these could affect the human food chain. This has been studied by Lingoot et al (27) who found that Gd-based contrast agents may reach the human food chain both from plants growing in fields which are irrigated with contaminated surface water and from animals which drink the water.…”