Cohort Profile: The China Metal-Exposed Workers Cohort Study (Jinchang Cohort)

The Jinchang Cohort was an ongoing 20-year ambispective cohort with unique metal exposures of an occupational population. Until now, the Jinchang Cohort has completed three phases of follow-up from January 2014 to December 2019. The baseline cohort was completed from June 2011 to December 2013, and a total of 48 001 people were included. Three phases of follow-ups included 46 713, 41 888 and 40 530 participants, respectively. The death data was collected from 2001 to 2020. The epidemiological, physical examination, physiological and biochemical data of the cohort were collected by using the methods of cross-section and prospective cohort study. Biological specimens were collected on baseline to establish a biological specimen bank. The concentrations of metals in urine and serum were detected by inductively coupled plasma mass spectrometry (ICP-MS). The new areas of research aim to study the all-cases mortality, the burden of diseases, heavy metals and diseases, and course of the chain from disease to high-risk outcomes using a combination of macro and micro means, which provided scientific basic to explore pathogenesis of multi-etiology and multi-disease, and to evaluate the effects of the intervention measures in the population.

Food web on ice: a pragmatic approach to investigate the trophic magnification of chemicals of concern

Background The trophic magnification factor (TMF) is a metric that describes the average trophic magnification of a chemical through a food web. TMFs may be used for the risk assessment of chemicals, although TMFs for single compounds can vary considerably between studies despite thorough guidance available in the literature to eliminate potential sources of error. The practical realization of a TMF investigation is quite complex and often only a few chemicals can be investigated due to low sample masses. This study evaluated whether a pragmatic approach involving the large-scale cryogenic sample preparation practices of the German Environmental Specimen Bank (ESB) is feasible. This approach could provide sufficient sample masses for a reduced set of samples allowing screenings for a broad spectrum of substances and by that enabling a systematic comparison of derived TMFs. Furthermore, it was assessed whether plausible TMFs can be derived with the ‘Food web on ice’ approach via a comparison with literature TMF values. Results This investigation at Lake Templin near Potsdam is the first TMF study for a German freshwater ecosystem and aimed to derive TMFs that are appropriate for regulatory purposes. A set of 15 composite biota samples was obtained and analyzed for an extended set of benchmark chemicals such as persistent organic pollutants, mercury and perfluoroalkyl substances. TMFs were calculated for all substances that were present in > 80% of the biota samples. For example, in the case of polychlorinated biphenyls, TMFs from 1.7 to 2.5 were determined and comparisons to literature TMFs determined in other freshwater ecosystems showed similarities. We showed that 32 out of 35 compounds analyzed had TMFs significantly above 1. In the remaining three cases, the correlations were not statistically significant. Conclusions The derived food web samples allow for an on-demand analysis and are ready-to-use for additional investigations. Since substances with non-lipophilic accumulation properties were also included in the list of analyzed substances, we conclude that the ‘Food web on ice’ provides samples which could be used to characterize the trophic magnification potential of substances with unknown bioaccumulation properties in the future which in return could be compared directly to the benchmarking patterns provided here.