SCHEER - Scientific Opinion on "Draft Environmental Quality Standards for Priority Substances under the WFD" - 5-6 rings PolyAromatic Hydrocarbons (PAHs)

SCHEER WG on Water Framework Directive
SCHEER members: Marian Scott (Chair), Marco Vighi (Rapporteur), Thomas Backhaus, Teresa Borges, Peter Hoet, Pim de Voogt, Rodica Mariana Ion
External experts: Andrew Johnson, Jan Linders
Contact: SANTE-SCHEERec [dot] europa [dot] eu (SANTE-SCHEER[at]ec[dot]europa[dot]eu)
On request from: European Commission
Adopted on: 9 March 2023

The dossier on Environmental Quality Standards for “PAHs” is reviewed by the SCHEER according to the general mandate on EQS dossiers.

The proposed dossier is a revision of a previous EQS dossier (2018) based on recent data and the procedure proposed in the new EQS Technical Guidance (2018). However, several sections of the dossier refer to old technical documents (2011). It is the opinion of the SCHEER that all the procedures must be updated, according with the 2018 EQS Technical Guidance.

For PAHs to be measured together with benzo[a]pyrene (BaP), the JRC selected an eight-component PAH mixture (BaP, benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, dibenz[a,h]anthracene, benzo[g,h,i]perylene and chrysene) as described by EFSA (2008).

For BaP the SCHEER does not endorse the MAC-QSs, while the AA-QS_{freshwater, eco} and AA-QS_{salt water, eco} of 0.022 μg L^-1 are endorsed by the SCHEER.

For benzo[b]fluoranthene and benzo[k]fluoranthene the AA-QS_{fw, eco} and AA-QS_{sw, eco} of 0.017 μg L^-1 are endorsed by the SCHEER. The SCHEER agrees on using the same values for MAC-QSs.

For benzo[g,h,i]perylene the AA-QS_{fw, eco} of 0.0082 μg L^-1 and the AA-QS_{sw, eco} of 0.00082 μg L^-1 are endorsed by the SCHEER. The SCHEER agrees on using the same values for MAC-QSs.

For indeno[g,h,i]perylene, the MAC-QS and AA-QS cannot be derived due to the lack of data.

Toxicity data to derive a QSbiota, secpois are available only for BaP. The method of the energy-normalised diet concentrations was correctly applied to the NOAEL of 5 mg kg_bw^-1 d^-1 obtaining a final QS_{biota, secpois, fw} of 0.67 mg kg_ww^-1 for fish, 0.60 mg kg_ww^-1 for crustaceans, and 0.19 mg kg_ww^-1 for bivalves, which are endorsed by the SCHEER. For the back-calculation to water concentration, the SCHEER does not endorse the QS_fw,biota for fish due to inappropriate selection of the final BAF value for fish. The SCHEER endorses the QS_{fw, biota} for crustaceans of 7.4 ng L^-1 and the QS_{fw, biota} for bivalves of 5.7 ng L^-1.

For human health, BaP is assumed as a suitable indicator for all PAHs. The SCHEER endorses the QS_{biota, hh} of 0.61 μg kg_biota^-1 as BaP equivalent. The SCHEER endorses this value. The SCHEER notes that a QS_{water hh biota} has not been calculated. The EU standard for drinking water for the sum of PAHs is equal to 0.1 μg L^-1 while for BaP it is equal to 0.01 μg L^-1. The SCHEER is of the opinion that a QS_{dw, hh} should be derived for BaP.

Different critical EQSs should be identified for the different chemicals. Considering the endorsed EQSs, the QS_{fw, biota} for bivalves = 5.7 ng L^-1 is identified for BaP and the AA-QS_{sw, eco} = 0.82 ng L^-1 is identified for benzo[g,h,i]perylene.

The SCHEER notes that in the dossier, contrary to what the title of the dossier suggests, 4-ring PAHs are also included.

Keywords:

PAHs, Water Framework Directive, environmental quality standards

Opinion to be cited as:

SCHEER (Scientific Committee on Health, Environmental and Emerging Risks), Final Opinion on Draft Environmental Quality Standards for Priority Substances under the Water Framework Directive" - PAHs, 9 March 2023.