Sense about Science ? equipping people to make sense of science and evidence
For the record
Response to claims that pesticides are causing a fertility crisis "worse than global warming"
An article in The Telegraph on 23rd October with the headline “Avoid 'toxic June' when trying to conceive, say scientists” reported research on birth rates that had been presented to the annual meeting of the American Society for Reproductive Medicine in Baltimore, USA.
The research showed a fall in healthy babies and in general birth rate in February. The study author Dr Paul Winchester of Indiana University is quoted in the piece saying he “believes that chemicals in the environment could be causing a huge fertility crisis in the west which may be bigger than global warming”. He studied US birth data going back to the 1900s and found that there used to be a birth peak in February but this trend has reversed in line with the wide spread use of pesticides.
Allan Pacey, Professor of Andrology, University of Sheffield:
“This is a speculative study which has been presented at a conference and has not yet gone through the peer review process. So it is impossible for me to tell how reliable the data analysis has been and whether the authors have interpreted it appropriately.”
“Fertility and perinatal health are affected by many biological and social factors and many things have changed in our lives since 1900. Whilst it may be true that an increased use of pesticides in June may account for lower birth rate and infant survival, US citizens are also more likely to buy a house in June so perhaps its exposure to packing crates or solicitors which are the real reason? In fact this illustrates nicely the dangers of trying to make correlative connections between data of this type.”
Document type: For The Record
Published: 2 November 2015