Transfer and effects of 1,2,3,5,7-pentachloronaphthalene in an experimental food chain

Risks for animal and human health related to the presence of polychlorinated naphthalenes (PCNs) in feed and food

“…No effects have been recorded in fish following exposure to PCNs, except than upregulation of genes and proteins involved in xenobiotic metabolism and in particular Cyp1a. In the study by Slootweg et al (2015), survival, body weight, body length, specific liver weight (liver specific index) and food conversion rate in rainbow trout were unaffected by exposure to 32.8 mg PCN-52/kg feed (dry weight). This concentration in the feed was taken as a NOAEL for PCN-52 in fish.…”

“…PCNs, like PCBs, may be eliminated unchanged from fish, through faecal excretion and diffusion across the gills (James & Kleinow, 2014). According to Slootweg et al (2015) a relatively small percentage of between 7% and 9% of PCN-52 was recovered in the faeces of juvenile rainbow trout and reflected the compound associated with undigested worms excreted by the fish while the main fraction of diet-bound PCN-52 was bioavailable for uptake.…”

“…Absorption efficiency of PCN‐52 from feed (benthic worms) by juvenile rainbow trout ( Oncorhynchus mykiss ) as the percentage of total dietary intake of trout at days 14 and 28 has been determined to 60% (Slootweg et al., 2015 ). Juvenile salmon ( Salmo salar ) exposed to Halowax 1001, 1014 and 1051 (0.1–10 μg/g feed) for 8, 13, 17 and 41 weeks accumulated from triCNs to octaCN.…”

“…PCN‐52, administered with feed (benthic worms) to juvenile rainbow trout ( Oncorhynchus mykiss ) for 28 days at daily doses of 0.13, 0.27 and 0.55 μg/g fish, induced the first phase of metabolism which was evident from the significant up‐regulation of cyp1a1 expression in the liver, while no changes were seen in Abcb1a transcript levels. Biotransformation of PCN‐52 could contribute to the 25%–40% of the total PCN‐52 intakes which were not recovered in the trout tissue or faeces (Slootweg et al., 2015 ).…”

Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures

“…the polymer acts as a reservoir of the test chemical which compensates for the test chemical lost from the system. Silicone can also be cast into the bottom of test jars or sheets placed in test wells on plates Slootweg et al, 2015;Smith et al, 2010b). Further, test chemical injected into silicone tubing has been shown as a successful application of passive dosing (Redman et al, 2017).…”