UV Radiation, Ozone Layer

Depletion and its effects on

human health

Professor Nigel Paul

Environmental Effects Assessment Panel

and

Lancaster University UK.

n.paul@lancaster.ac.uk

Ozone, UV radiation and health

Ozone, UV radiation and health

INDIRECT EFFECTS OF OZONE DEPLETION ON HEALTH

Uncontrolled ozone

depletion ↓

major reductions

Crops

Fisheries

DIRECT EFFECTS OF OZONE DEPLETION ON HEALTH

Air quality

Water quality

Complex! Effects of

current UV probably broadly positive.

STRATOSPHERIC OZONE INCREASED ULTRAVIOLET RADIATION

Damaging effects too much UV

Damaging effects of too little UV

Research over the last 30 years has clarified that damage to human health can result from either too much or too little UV radiation

The extent of individual UV exposure depends on:-

• Location and time (latitude, altitude, time of year, time of day)

• Amount of time spent out-doors (work and leisure).

• Choice of clothing and sunglasses (cover up or not).

Ozone, UV radiation and health

• Location and time (latitude, altitude, time of year, time of day)

• Amount of time spent out-doors (work and leisure).

• Choice of clothing (cover up or not).

Damaging effects of too much UV

Damaging effects of too little UV

Ozone, UV radiation and health

The massive increase UV exposure would have overwhelmed other factors

Without the Montreal Protocol the balance shifts towards damage due to too much UV radiation.

Effects of increased UV radiation

Health

40+ 40+ 40+ 40+

40+ 40+ 40+ 40+

Effects of increased UV radiation

Health SHORT TERM LONG-TERM

SKIN Sunburn Increased skin-cancers Basal cell & squamous cell carcinomas Malignant melanoma

EYES Inflammation (photo-conjunctivitis)

Increased cataract (and other eye diseases)

IMMUNE SYSTEM: immune suppression leading to increased susceptibility to infection, reduced response to vaccinations

?

The Montreal Protocol & eye disease

Cataracts are a major cause of blindness world-wide.

Short-wavelength UV, most affected by ozone depletion, is linked especially to an increased risk of cortical cataract.

2014 US-EPA REPORT

As a result of the successful implementation of the Montreal Protocol there will be up to 45-50 million fewer cases of cataract in the USA.

No comparable estimates for other countries.

40+ 40+ 40+ 40+

Effects of increased UV radiation

Health SHORT TERM LONG-TERM

SKIN Sunburn Increased skin-cancers Basal cell & squamous cell carcinomas Malignant melanoma

EYES Inflammation (photo-conjunctivitis)

Increased cataract (and other eye diseases)

IMMUNE SYSTEM: immune suppression leading to increased susceptibility to infection, reduced response to vaccinations

?

Total number of new cases of skin cancer per million people per year avoided by the Montreal

Protocol in the year 2030. From van Dijk et al., 2013

Models of the “world avoided” estimate that there would have been

approximately two million more cases of skin cancer a year by

2030 without the Montreal Protocol.

The Montreal Protocol & skin cancer

There is a long lag period between UV damage and the onset of skin cancers. As a result, changes modelled for 2030 reflect relatively small increases in UV to that date. Longer term?

2014 US-EPA REPORT

As a result of the successful implementation of the Montreal Protocol there will be:

280-340 million fewer cases of skin cancer in people born between 1890 and 2100 in the USA.

Approx. 1.6 million fewer deaths due to skin cancer

No such estimates for the rest of the world.

The Montreal Protocol & skin cancer

The Montreal Protocol & health