Inom ramen för nationell miljöövervakning har en screeningundersökning genomförts avseende metallerna platina, palladium, rhodium och silver. Andra metaller såsom cerium och koppar ingick också i studien. Undersökningen syftade främst till:

- Att beskriva förekomsten av platina, palladium, rhodium och silver i bakgrundsområden och i urbana områden i Sverige, genom analys av sediment, ytvatten, dagvatten, avloppsvatten, slam och fisk.

- Att bedöma om halterna av dessa metaller är förhöjda i urbana miljöer relativt bakgrundsområden.

- Att översiktligt bedöma om halterna förändrats under de senaste årtiondena.

- Att bedöma human exponering

A screening environmental monitoring study was performed on platinum, palladium, rhodium and silver. Other metals such as cerium and copper was also included. The study is part of the national environmental monitoring program run by the Swedish EPA. The major goals of the study were:

q To provide new data on the environmental levels of platinum groups elements and silver in urban and background areas in Sweden through analysis of sediments, surface water, stormwater, waste water, sludge and fish.

q To assess whether levels are higher in urban areas compared to rural areas.

q To assess whether there are indications of time trends.

q To assess human exposure.

The study consists of a national programme (60 samples) and three regional programs (14 samples). Major matrices were sediments and urine.

There were no pronounced indications that background lakes were affected by anthropogenic emissions of Pt, Pd or Rh. For silver, sediment concentrations indicate a possible increase in background lakes over the last decade or two. Data is however too limited to state this as a general phenomenon.

To elicudate possible emission sources analyses were performed on stormwater, urban runoff pond sediments, sewage sludge and waste water effluents. Platinum, Rh and Pd were enriched in stormwaters and runoff pond sediments, in agreement with road traffic as a major emission source of these metals. Data also consistently show that muncipal waste waters were enriched in Pt relative to the composition of stormwaters. The medical use of Pt is a suggested explanation.

In ten recipients affected by urban emissions or road traffic, sediment levels of Pd, Pt, Rh and Ag were generally higher than background levels. The platinum group elements (PGE) profile in these sediments were compared to the profiles for waste water effluent and stormwaters, respectively. Although several of these recipients were recipients to municipal waste water treatment plants, most sediments show profiles similar to stormwater. This indicates that vehicle catalysts still is the major source of Pt, Pd and Rh to these recipients.

Surface water and fish were also analysed from a few of these urban recipients. Palladium concentrations were detected in urban surface waters, but neither Pt, Rh nor Ag were detected.

Fish (perch) from these sites did not display concentrations of Pd, Pt or Rh above the analytical reporting limit. Silver in these fish samples occurred in similar or lower concentrations than in the background lakes.

To assess time trends, fish from background lakes sampled in 1985, 2000 and 2014 were analysed. Furthermore sediment from both background lakes and urban lakes were analysed at several depths, corresponding to at least the last 2-3 decades. Overall there were no indications of pronounced time trends.

None of the PGEs were detected in human urine from 20 individuals, except for two observations of platinum. Silver was detected in ca 50% of the urine samples and levels were similar to a 15 year old study.

The overall assessment of the data in this study is that neither Pt, Pd, Rh nor Ag give rise to a concern for ecotoxicological effects. It should though be considered that although some ecotoxicological data exist, effect criteria for the PGEs have not been established and the monitoring data presented are limited.