1.
Why be concerned about
chemicals in the environment?
There are many challenges to our environment and health which we
need to consider. These include floods, droughts, habitat destruction,
climate change causing ecological disruption, arrival of alien species and
novel diseases.
So why should we pay any attention to chemicals in the environment?
Professor Andrew Johnson on behalf of the Hazardous
Substances Advisory Committee".

2.
The magnitude of the challenge
• More than 80,000 chemicals are used and disposed of every day.
• Many will contaminate our soils, rivers, groundwater and coastal
waters.
• Some accumulate in wildlife and humans producing adverse effects.
• We don’t understand the extent of the risks.
• The chemicals market is growing by about 2000 new compounds
per year.

3.
0
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E201
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R103
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0187C
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0079
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Eel,Sunbury (non tidal) Eel, Woolwich (tidal) Roach
carc.,
Marlow
Roach
Carc., Old
Windsor
Bleak carc.,
Marlow
Bleak Sunbury whole
ng/glipid
PCBs in carcass of eel,roach,bleak autumn 2007 PCB 199
PCB 194
PCB 189
PCB 188
PCB 187
PCB 183
PCB 180
PCB 174
PCB 170
PCB 167
PCB 158
PCB 157
PCB 156
PCB 155
PCB 132/153
PCB 151
PCB 149
PCB 141
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PCB 123
PCB 118
PCB 114
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PCB 105
PCB 104
PCB 99
PCB 90/101
PCB 95
PCB 87
PCB 74
PCB 70
PCB 54
PCB 52
PCB 49
PCB 44
PCB 41/64
PCB 28/31
PCB 22
PCB 18
100s’ of chemicals can be found in our fish & other wildlife
today
CEH fish tissue archive for the UK
Polychlorinated biphenyls
Popular as electrical insulators
Banned in 2001 but still
commonly found in
wildlife tissue

4.
Chemical problems in the UK can arise
unexpectedly -DDT
Unanticipated effect of egg shell
thinning almost wiped out UK
birds of prey
Has DDT now all gone away?
A very effective insecticide but…………..

5.
Some UK fish remain highly contaminated
with the historic pesticide DDT
Fish heavily contaminated at the River Lee at Wheathampstead
Young fish
are severely contaminated
living in proximity to
a pesticide
Factory which closed many
decades ago at
Wheathampstead on the
River Lee
CEH fish tissue archive for the UK
The choices we make with chemicals can cast a long shadow!
Banned from use in the UK in 1984

6.
Some chemical problems that hit home in
the UK – TBT
Populations of shell fish were hit hard by this anti-fouling product
It had endocrine disrupting effects – turning females into males!

7.
A current worry is fish becoming infertile due to
estrogen hormones excreted by humans
Changes in male fish
testes leading to
reduced fertility

8.
National risk
assessment Map for
endocrine
disruption in fish
Predicted
Risk Class
No risk
At risk
High risk
Being a densely populated small island, so exposure of fish to sewage effluent and the
associated chemicals would be high for England. This is the predicted risk for endocrine
disruption to fish
Williams, R.J., Keller, V.J.D., Johnson, A.C., Young, A.R., Holmes, M.G.R., Wells, C., Gross-Sorokin, M. Benstead, R. (2009).
A national risk assessment for intersex in fish arising from steroid estrogens. Environmental Toxicology and Chemistry
28, 220-230.

9.
Many sewage treatment plants can be found along our lowland rivers
Predicting steroid estrogen concentrations along the Thames catchment
There are 300 large and small
sewage treatment plants
discharging into the non-
Tidal Thames
In summer in Reading, Berkshire
the river can be 1/3 treated
sewage effluent!
LONDON
Each dot is a large
sewage treatment plant!

10.
Why worry about chemicals in the UK
environment in particular?
• Could we not rely on research from France or Germany to inform our
approach to chemicals?
• We have many areas with a high density of population and historic
narrow streets with persistent air pollution
• Many European countries now incinerate their sewage sludge. But
we discharge a high proportion of our sludge to land for farmers.
This sludge can transfer many undesirable contaminants to our soils.
• We in the UK are particularly exposed to contaminants discharged to
water through our sewage treatment plants…….Why is that?

11.
0
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Dilutionfactors 25%ile dilution factors for European nations
How much water do Europe’s countries have
available to dilute their waste?
We have a significant proportion of very populous regions
in areas of modest rainfall – low dilution, less than a factor of 10!
Keller V.D.J., Williams, R.J., Lofthouse, C., Johnson, A.C. (2014). Worldwide estimation of river concentrations of any chemical originating from
sewage-treatment plants using dilution factors. Environmental Toxicology and Chemistry, 33, 447-452.
UK will be disproportionately
affected by any EU
legislation to control
common down the drain
chemicals
Hard for us to meet the
standards if we have so
little dilution to help us

12.
What costs are involved in the UK?
• Approximate gross value of the chemicals industry in the UK £8.9
billion in 2014 (ONS)
• Approximate gross value of the pharma industry in the UK £6.0 billion
in 2014 (ONS)
• Approximate cost of REACH chemicals testing/registration across
Europe £845 million as of 2011
• Investment in protecting water from sewage discharge (for Thames
Water £100 million on removing PO4, £800 million on reducing gross
organics and £4.5 billion on reducing sewer overflows since 1993)
• Possible costs of further improving sewage treatment to eliminate
pharmaceuticals and other trace contaminants across the UK - £27-31
billion over 20 years (which would double our water bills)

13.
Current and future challenges we are
grappling with…..
• Increasing use, diversity and volumes of chemicals used
• Increasingly diverse burden of chemical contaminants found in
humans and wildlife
• Our particular geographic vulnerability
• Endocrine disrupting chemicals
• Neonicotinoid pesticides (and bees)
• Nanoparticles
• Microplastics
• Increased antibiotic resistance in natural environments
• Combination or mixture effects of chemicals acting together
• Something we haven’t thought of yet!!!

14.
There are good news stories about chemicals
where policy makers and scientists worked
together to help the environment
• Banning of DDT and many other persistent of
bioaccumulative pesticides led to the return of our birds
of prey
• Reduction in emissions from coal power stations so less
acid rain
• Banning of TBT led to the return of water snails, oysters
and improved overall estuarine biodiversity
• Elimination of highly bioaccumulative metal mercury

15.
We want UK society to benefit from chemicals whilst
maintaining and improving the integrity of the
natural environment.
This challenge will continue into the foreseeable
future.
What is not in doubt is that the UK exposure to
down the drain chemicals will always be amongst
the highest in Europe

16.
Examples of how HSAC can help?
• Advise on chemicals research policy.
• Provide evidence-based guidance on how to
better evaluate chemical toxicity.
• Advise on emerging chemical threats nationally
and internationally.
• Identify the strengths and weaknesses of
chemical regulation and advise on improvements
• Offer a vision of the “chemical environment “ we
want to achieve for the UK in the future.

17.
We only have one of these!