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No. 210: NOVANA screening, evaluation of selected environmentally hazardous pollutants

Lassen, P. & Carvalho, P. 2021. NOVANA screening, evaluering af udvalgte miljøfarlige forurenende stoffer. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 66 s. - Teknisk rapport nr. 210
http://dce2.au.dk/pub/TR210.pdf

Summary

The report reviews data from screening studies conducted from 2017-2019. The studies included the following 10 pesticides: azoxystrobin, carbendazim, diazinon, diflufenican, irgarol / cybutryne, pirimicarb, propiconazole, pyraclostrobin, tebuconazole and terbutryn. The compounds were measured in water samples from 27 streams, wastewater from inlets and outlets at two RBU plants and sediment from 10 RBU plants. In 2017/18, samples were collected from streams, wastewater and sediment from facilities for rainfall discharges, in the following called RBU. In 2018/19, samples were collected from streams.

In addition, two degradation products from diflufenican; AE-B and AE-0 as well as three benzalkonium chloride compounds (BAC); 12-BAC; 14-BAC and 16-BAC were measured in the samples. The BAC compounds were measured in freshwater, RBU wastewater and RBU sediment in 2017/18. AE-B and AE-0 were measured in fresh water and RBU wastewater in a limited number of samples as an addendum to the other studies. In streams the results showed that all pesticides and BAC substances were found but in variable frequencies. Diazinon, irgarol /cybutryne and pyraclostrobin as well as 16-BAC were found in quantifiable amounts in few streams; less than 25% of the samples. EA-B and EA-0 were not found in the samples. For the remaining compounds, the percentage of quantifiable samples were 64-86%. Carbendazim, diflufenican and pirimicarb were found in 93-100% of the samples and they were generally measured in high concentrations (median about 4-5 ng/l). The three BAC compounds were found with a lower frequency but with higher median values (approximately 10-50 µg/l).

In RBU wastewater from inlet and outlet and RBU sediment carbendazim, diflufenican and tebuconazole were found among the pesticides with the highest concentrations and with a frequency of 100%. Diazinon and pirimicarb were found in low concentrations, while irgarol / cybutryne and pyraclostrobin were found in no or few of the samples. The BAC substances were also found in all wastewater samples from inlet and outlet as well as in sediment samples from RBU. The BAC substances were found in significantly higher concentrations, around a factor of 100-1000 times higher compared to the measured pesticides. Further, the BAC substances are classified as very toxic to the aquatic environment, indicating that their environmental impact must be significantly higher compared to the measured pesticides. In general, the results from the RBU sediments show the same picture as the RBU wastewater.