Two extremely interesting articles – views from the relevant Royal Society of Medicine Conference last week in London by Dr. Evely Stefanaki are more than relevant to our shipping international readership given the current heatwaves. Seafarers in all ranks, as well as passengers of cruise ships in particular, are the most vulnerable workforce and people and the importance of these views are paramount:
The first one is on Climate change and human skin cancer in the context of Ultraviolet Radiation; she says:
I was delighted to be present at Professor Anthony Young’s speech in the Royal Society of Medicine’s Health Emergency for Climate Change conference. Prof. A. Young is an emeritus Professor of Photo dermatology at King’s College London and a member of the environmental assessments panel of the United Nations. His speech is interesting for all of us, particularly after recent soaring temperatures in the Mediterranean.
In a short summary, this is what he had to say and interesting developments regarding the climate change and human skin cancer in the context of Ultraviolet Radiation.
There are three different types of ultraviolet radiation: UVC doesn’t reach the earth’s surface as it’s totally absorbed by the ozone layer, UVB reaches the earth’s surface at 5% and it is strongly attenuated by the ozone layer, and mostly UVA which is minimally affected by the ozone layer. UVB is the main source of most skin cancers, (keratinocyte cancers and melanoma), but it also has benefits, specifically vitamin D synthesis.
Professor Young spoke of some alarming changes in skin cancer prevalence over the last few decades. In Iceland, which is not a sunny country, over the period of 1981- 2017, basal cell carcinomas increased between 2.3 and 3.7 in men and women respectively. In the Netherlands over the period of 1989- 2017, squamous cell carcinoma in situ showed a 6-fold and a 7.7-fold increase in men and women respectively. China between 1990 – 2017, showed a 6.1% increase in melanoma and in the USA between 2001- 2015 the increase was 1.8% in all ethnicities over 40 years. Generally, in most countries skin cancer incident is increasing.
It was discovered that synthetic chemicals, for example chlorofluorocarbons, deplete stratospheric ozone and these are known as ozone depleting substances. The world’s governments got together in 1985 to adopt the “Vienna Convention for the Protection of the Ozone Layer” in response to the prospect of increasing ozone depletion. In 1987 the Montreal Protocol was established as an international treaty designed to control the production and consumption of CFCs and other ozone-depleting substances and their replacement with hydrofluorocarbons that are less damaging to the ozone layer .The most recent amendment was the Kigali amendment in 2016, which planned to phase down the CFCs because they are greenhouse gases and that obviously is important in terms of global warming.
So, what are the projected effects of the Montreal Protocol on skin cancer? The US environmental protection agency used “The atmospheric health effects framework model” and it assumed that some protection behaviour would remain constant. This estimated that it would prevent 432 million cases of keratinocyte cancer and 11 million cases of melanoma in the US for people born between 1890 and 2100 also would prevent 2.3 million deaths mainly from melanoma. The greatest effect would be on people born between 1960 and 1980 because they experienced the peaks of ozone depletion. Those born from 2040 onwards probably will have no effect because the ozone level will have recovered.
The Montreal Protocol is an excellent example of long-term international cooperation in addressing a global problem. The preventative action has and will reduce the production of ozone decreasing substance and will have a major beneficial effect on skin health in particular skin cancer. This is also expected to reduce economic burdens with skin cancer, which is a rather expensive condition to treat.
On the second one, she stresses on Sunscreens, cancer and protecting our planet:
Eleni Linos is a Professor of Dermatology at Stanford University and deputy editor of the British Journal of Dermatology. She spoke of the use of sunscreens, the potential toxicity for the marine life and ways to protect both from skin cancer and marine life pollution.
Throughout the decades the use of sunscreen has increased in direct response to the increase in skin cancer. There are over 5 million new skin cancer cases each year in the US alone and sunscreen recommendations have grown to protect patients from these risks.
The sunscreen market is worth over 13 billion US dollars globally. There are concerns about chemicals in sunscreen, particularly oxybenzone, being toxic to corals leading to coral bleaching affecting photosynthesis of green algae decreasing fertility in fish affecting the immune and reproductive functions of sea urchins and even accumulation in dolphins after laboratory experiments, demonstrated the above. The sunscreen plastic bottles as well as the packaging they’re shipped in are also a major concern.
Based on this evidence, in 2021 Hawaii became the first US state to ban the sale or distribution of any sunscreens containing these chemicals. There was some concern in the Dermatology community due to the major problem of skin cancer. Each year in the US there are more than 5.4 million skin cancers, including basal and squamous cell cancers, over a hundred thousand new melanomas and over seven thousand deaths from melanoma. How do we address this dilemma of protecting our planet while also protecting our skin?
The solution that can address both, is alternative forms of sun protection. These include, staying in the shade, wearing broad brimmed hats, long-sleeved shirts and avoiding the midday sun. These are all solutions that can both prevent skin cancer as well as protect the planet.
The recommendation I would give my patients is to use zinc and titanium mineral sunscreens especially the non-nano kind, which are incredibly effective. Reorganizing our medical advice to de-emphasize sunscreen as the first form of sun protection and instead focus on physical measures can make a big difference to the protection of the marine environment.
