Researchers have found that children born during years with high sunlight had a higher probability of dying early than those born in the years with less sunlight and those who survive face infertility passing on to their offsprings too.
Researchers from Norway, who conducted the stydy, said on average, the lifespan of children born in years that had a great deal of solar activity was 5.2 years shorter than other children. The probability of dying during the first two years of life is very high, said researchers.
“There are probably many factors that come into play but we have measured a long-term effect over generations. The conclusion is that you should not sunbathe if you are pregnant and want to have a lot of grandchildren,” said lead author Gine Roll Skjaervoe from the Norwegian University of Science and Technology (NTNU).
The team also found that children born in years with lots of sunshine but survived were more likely to have fewer children, or becoming infertile and pass the gene to their offsprings too. The study focused on increased ultraviolet (UV) radiation during the high sunlight years with maximum solar activity and its effect across generations.
Skjaervoe based his study on church records from 1750 to 1900 involving 9,000 people and used the information on the number of sunspots as an indication of the amount of UV radiation in a given year.
The sunspots reached a maximum every 11 years on average, which results in more UV radiation on Earth during years with high sunspot and solar activity. Though UV radiation can have positive effects on human vitamin D levels, it can reduce vitamin B9 (folate) and low folate levels during pregnancy are linked to higher child mortality.
The study also found that the lowest socio-economic strate were most affected by UV radiation, especially women who worked in the fields with maximum exposure to the sun than other women, besides living on a poorer diet.
The study findings have been published in the journal Proceedings of the Royal Society (B).