Risk Assessment of Chemicals in the Welsh Marine Environment - an overview of recent and new policy requirements

1. Risk Assessment of Chemicals in the Welsh
Marine Environment
an overview of recent evidence and new policy requirements
Thomaz Andrade – Natural Resources Wales
Marine Evidence Conference - Swansea University, 18 Sep 2019

2. Risk Assessment - Drivers
Why  Generate the evidence to support management actions
optimise the design of the monitoring programme, and the programme of measures
What  Risk of failing to comply with legal requirements
standards set in legislation based on best available ecotoxicological evidence
LEGAL DRIVERS:
Bigger picture: wider programme includes other aspects of the water environment
(e.g. physical modifications, ecology, nutrients, faecal contamination, flow rates)
• Water Framework Directive: review of the impact of
human activity on the status of surface and groundwaters
• Environment Act (Wales): understand the risks to
“Sustainable Management of Natural Resources”

3. Choosing the right ‘matrix’
• Water data not reliable to identify risks from some ubiquitous,
persistent, bioaccumulative and toxic substances – uPBTs
• Hydrophobic substances may be hard to detect in water due to
adsorptions to sediment / fatty tissue and accumulate through
food webs
 risks to top predators, including humans.

4. • New requirement from the Priority Substances
Directive (2013)
• Fish sampling added to long term mussels
programme in 2017/18 to provide further evidence
• Risk assessed for substances with WFD failures
in the most recent classification (2018) and new
substances added in the Priority Substances
Directive (16 out of 78)
Choosing the right ‘matrix’ - Biota

5. Substance Scale Source Protection Goal
Widespread
concern
Local
concern
Insufficient
data
Sectoruse/
activity
Abandoned
mines
Legacy
chemicals
Domestic
effluent
Protecting
aquaticlife
Protecting
foodchains
Copper ✓ ✓ ✓
Zinc ✓ ✓ ✓
Cadmium ✓ ✓ ✓
Lead ✓ ✓ ✓
Iron ✓ ✓ ✓
Manganese ✓ ✓ ✓
Nickel ✓ ✓ ✓
Mercury ✓ ✓ ✓
Flame retardants (PBDE) ✓ ✓ ✓
Hydrocarbons (PAH) ✓ ✓ ✓
Tributyltin (TBT) ✓ ✓ ✓
Hexabromocyclododecane (HBCDD) ✓ ✓ ✓
Perfluorooctanesulfonic acid (PFOS) ✓ ✓ ✓
Cypermethrin ✓ ✓ ✓ ✓
Triclosan ✓ ✓ ✓
Dioxins and dioxin-like compounds ✓ ✓ ✓

6. Methodology
Little data for some chemicals – Multiple data sources used
• Previous WFD classification
• Historical data (10 years)
• Recent biota sampling results (4 estuaries and 4 rivers)
• Waste water and industrial effluent quality
• Land use / pressures assessment
WFD status Status Confidence Risk level
Less than Good High / Medium At Risk
Less than Good (likely) Low Probably at risk
At least Good (likely) Low Probably not at risk
At least Good High / Medium Not at risk
Biota sampling sites

7. Biota results - “Worst offenders”
Flame Retardants - BDPE
(Brominated diphenylethers)
TOTAL PBDE (µg/kg; EQS=0.0085)
ESTUARINE (Mussels)
Conwy 0.36
Mawddach 0.08
Milford Haven (Lawrenny) 0.29
Mostyn Bank 0.33
FRESH WATERS
Llan 1.61
Rheidol 1.42
Rhymney 4.48
Soch 0.59
At risk
Probably at risk
Probably not at risk
Not at risk
Lakes
Transitional WB <5Km2

8. Biota results - “Worst offenders”
Mercury
• EQS = 20 µg/kg
• 100% failures if adjusted to trophic level 4
At risk
Probably at risk
Probably not at risk
Not at risk
Lakes
Transitional WB <5Km2

9. At risk
Probably at risk
Probably not at risk
Not at risk
Lakes
Transitional WB <5Km2
Biota results – other chemicals
PCBs (polychlorinated biphenyls):
detected in most places at trace levels in biota
(largely undetected in water, apart from 6 locations
with known historical contamination)
Dioxins: Only Octa-chlorinated detected at trace
levels
Furans: not detected
 Toxicity adjusted “Dioxin and dioxin-like
substances” below 20% EQS
Dioxins and dioxin-
like substances

10. PFOS – none in marine mussels;
<1/4 EQS in freshwater fish at urban/industrial
rivers, but model using water data suggest risk in
areas with high proportion of waste water inputs
PFOA – not detected
HBCDD (Hexabromocyclododecane)
Not detected
Polycyclic Aromatic Hydrocarbons (PAHs)
Detected in all estuaries, but < 15% EQS
Detected in 1 (out of 4) rivers (Usk) – 43% EQS
Biota results – other chemicals
At risk
Probably at risk
Probably not at risk
Not at risk
Lakes
Transitional WB <5Km2
PFOS

11. Water results – chemicals
TBT (Tributyltin)
• No detections since 2016 (LOQ=EQS)
• Marine levels (England) ~ 50% of
freshwaters
• Imposex in the dogwhelk (Nucella lapillus)
decreasing, low incidence since 2014 in all
Welsh sites
(Nicolaus and Barry, 2015)
Cypermethrin
• Standard too low to assess (marine EQS =
8x10-6µg/L; < LOQ)
• Modelled domestic effluent dilution in rivers
leading up to 80% EQS in freshwaters
• Agriculture inputs and accumulation in
estuarine sediments may be an issue
Triclosan
• Modelled domestic effluent dilution in rivers
leading up to 20% EQS
• Marine levels (England) lower than
freshwaters

12. Water results – metals
• No marine areas at risk
• Some failures in transitional waters:
• Zn: Ogmore and Tawe
• Cd: Ystwyth/Rheidol
• Mainly inland risks due to legacy metal
mines, especially Zn, Cd and Pb
Zn
At risk
Probably at risk
Probably not at risk
Not at risk
Lakes
Transitional WB <5Km2

13. Final remarks – take home message
• Broadly good news!
• Most chemicals below biota EQS, apart from PBDEs and Mercury (down trend).
• Measures are already in place, sources are mostly legacy issues
• The goal is to continue to detect downward trends
• Next steps
• Continue monitoring to better understand risks
• Identifying Emerging Contaminants: non-target passive sampling
• Effect-based assessments: using environmental DNA to assess impact of chemical signatures