Anthropogenic pollutants - an insidious threat to animal health and productivity? - Stewart M. Rhind

Anthropogenic pollutants – an
insidious threat to animal health and
productivity?

Stewart M. Rhind

Nothing new in this world …

• Volcanoes produce toxic gases etc
• Crude oil leaks from Earth’s crust
• Heavy metals from Bronze-age smelting

Nothing new in this world...
          …or is there?

● 1000s of synthetic compounds created
  during last 60 years
● Some have capacity to interfere with
  hormonal and other mechanisms
 - Endocrine Distrupting Compounds (EDCs)

Polycyclic aromatic
                               hydrocarbons (PAH)
    Bisphenol A
                                                                Polybrominated
                                                                diphenyl ethers (PBDE)

                                    ALL OF THEM!
Alkyl phenols
(detergents)
Plastics –
(phthalates)
                                                   Pesticides           Dioxins
                  Polychlorinated
                  biphenyls (PCB)

….but they’re not doing any harm!

People are living longer
 Farm animals are more productive
 Our rivers and seas are cleaner

….but EDCs are not like “old pollutants”

Properties

 Persistent and act additively

Properties

 Persistent and act additively

 Additive
  0 + 0 + 0 +….. = Physiological effect!

Properties

 Persistent and act additively
 Individuals differ in their responses to EDCs

Properties

 Persistent and act additively
 Individuals differ in their responses to EDCs
 Exposure and sensitivity differ with age

Properties

 Persistent and act additively
 Individuals differ in their responses to EDCs
 Exposure and sensitivity differ with age
 Transgenerational effects

Properties

 Persistent and act additively
 Individuals differ in their responses to EDCs
 Exposure and sensitivity differ with age
 Transgenerational effects
 Species differ

Properties

 Species differences in activities of
 multiple enzymes (100s -1000s x)
→ different EDC burdens

 Watkins, J.B. and Klaassen, C.D. 1986. J.Anim. Sci. 63 933-942

The Veterinary Viewpoint?
• Farmed species (sheep, pigs, etc)
• Companion animals (dogs, cats)
• Exotic species (reptiles, etc)?
• Farmed fish, molluscs, bees?

Are they exposed to EDCs?

 ALL animals are exposed – unlike in
 lab experiments, exposure is LOW
 level, LONG term and to MULTIPLE
 compounds

Farm animals
 Costs of artificial fertilisers are
 rising
 Recycling of waste is increasing
 Sewage sludge to land – an
 experimental model to study EDC
 effects on animals

Sewage sludge and sheep model
• Environmental dose
• Multiple compounds (100,000?)
… but is the EDC burden increased?

Sludge components

Concs (μg/kg DM) of single compounds
         Sludge      Inorganic fertiliser
PCBs     2- 33       N/D
PBDEs    10- 202     N/D – 1
PAHs     21 -2171    N/D

Soil concentrations

Maternal liver concentrations

Fetal liver concentrations

Maternal vs fetal

Maternal liver concentrations

Fetal liver concentrations

Maternal vs fetal

Summary

 Soil levels NOT significantly increased
 Tissue levels NOT significantly increased
 Maternal levels > fetal
 Sometimes fetal > maternal

Possible conclusions
 Sludge on pasture – no problem (?)
 Animal products are safe to eat (?)
 Environmental levels of EDCs are
 harmless (all below NOAEL)(?)
 Perhaps………..

Are sheep affected by exposure to
 sludge (and associated EDCs)?

   YES ……. but subtly
    (lessons from human health and
                fertility?)

Effects - Neuroendocrine

Effects – structural
(110 days gestation)

   Paul et al. (2005) Environmental Health Perspectives. 113 1580-1587

Enzyme activty (80 days gestation)

Structural effects (18 month ewes)

x10     Control         b         c

                        d

 a                      Treated       x10

Protein expression
(110 days gestation)

Bone structure (adult)

   Lind et al (2009) Science of the Total Environment 407 2200-2208

Behavioural effects

Conclusions

 Sludge application minimally
 increased environmental (soil) EDC
 burden and
 tissue EDC burden but…..
 it perturbed multiple physiological
 systems

Don’t forget other species!
 We keep dogs, cats etc as pets
 We eat and farm fish, shellfish, etc
 We depend on honey bees and other
 insects for pollination
 ALL can be affected by EDCs

It’s not just EDCs that affect
animal health and productivity!
 EDC effects interact with other stressors :
- Nutritional
- Thermal
- Management / social
- Osmotic

Conclusions
 Anthropogenic pollutants / EDCs can
 affect animal health / productivity
 But….
 They are essential components of our
 lives (pesticides, medicines, transport)
 Changes in use will come…..

.....but, meantime, they may
adversely, but subtly, affect
   our production systems,
    ecosystems and animal
            health

Rhind, S.,Zhang, Z., Le Velly, M., Mckenzie. C (in prep). Temporal trends and seasonal differences of Endocrine Disrupting Compound concentrations in agricultur
Rhind, S.,Zhang, Z., Calmettes, E., Mckenzie. C (in prep). Temporal trends and seasonal differences of polychlorinated biphenyls (PCBs) and Polybrominated Diph
Rhind, S.,Zhang, Z., Ruffie, H., Mckenzie. C (in prep). Temporal trends and seasonal differences of Di-(2-ethylhexyl phthalate ( DEHP) concentrations in soils treat

                                      Acknowledgements
            • Carol Kyle , Hutton Inst., Aberdeen
            • Hans Erhard, Hutton Inst., Aberdeen
            • Paul Fowler, Aberdeen University
            • Richard Sharpe, Edinburgh University
            • Corinne Cotinot, INRA, France
            • Neil Evans, Glasgow University
            • Kevin Sinclair, Nottingham University
            • Richard Lea, Nottingham University
            • Monica Lind, Uppsala University