Tritium is a radioisotope of hydrogen with a half-life of 12.32 years and was used for its luminescent properties by the watchmaking industry from 1962 to the 2008. Tritiated luminescent salts were integrated in the paints applied on the index and dial of watches and clocks. French and Swiss watchmaking workshops used more than 28 000 TBq of tritium over this period of time and produced almost 350 million watches. Despite the end of tritiated salts use in watchmaking workshops in 1992 in France and 2008 in Switzerland, high level of organically bound tritium (OBT) are still observed in sediments of the Rhône River downstream the Lake Geneva. Contamination of the Rhône River by tritiated hot particles since 1962 up to nowadays remains poorly documented. In order to assess the long term behavior and fate of technogenic tritium in this river and its trajectories in the river system, two sediment cores were collected at the upstream (UC) and downstream (DC) part of the Rhône River in France and OBT contents were determined. For both sedimentary cores, maximum OBT contents were registered over the 1980s when tritium was intensively used by watchmaking industries. These residual OBT contents are 1 000 to 10 000 fold higher than current natural background levels in riverine sediments. The OBT contents progressively decreased since 1989 with close effective half-life in upstream and downstream area (5 ± 2 years). The OBT contents were lower in DC than in UC due to the dilution by uncontaminated sediments delivered by tributaries not affected by the watchmaking industries. Trajectories analysis indicates that the resiliency of the Rhône River system in regards to this contamination would be reached in 14–70 years and in 14–28 years respectively for the upstream and downstream part of the river.

t是氢的放射性同位素，其半衰期为12.32年，从1962年到2008年被制表业用于其发光性能。Tri化的发光盐被集成到钟表的刻度盘和表盘上的涂料中。在这段时间内，法国和瑞士的制表工场使用了超过28000 TBq的and，生产了近3.5亿只手表。尽管1992年在法国和2008年在瑞士的制表工坊中已不再使用tri盐，但在日内瓦湖下游罗纳河的沉积物中仍观察到高水平的有机结合tri（OBT）。自1962年至今，tri化的热粒子对罗纳河的污染仍然鲜有记载。为了评估该river及其在河系中的轨迹的长期行为和命运，在法国罗纳河的上游（UC）和下游（DC）部分收集了两个沉积物岩心和OBT含量被确定。对于两个沉积岩心，1980年代制表业大量使用tri时，OBT含量最高。这些残留的OBT含量比河流沉积物中当前的自然本底水平高出1000至10000倍。自1989年以来，OBT含量逐渐下降，在上游和下游区域的有效半衰期接近（5±2年）。由于不受制表业影响的支流输送的未污染沉积物稀释了DC中的OBT含量，因此低于DC中的OBT含量。