The chemical bisphenol A, or BPA, is used to make polycarbonate plastic, epoxy resins, and other materials. It is commonly used in food contact materials, such as plastic water bottles. Its health effects on humans are unclear, but concerns have been raised because it can behave in a similar way to the hormone estrogen, and its use in food contact materials could be a source of exposure for humans. Studies have shown that nearly all people have BPA in their urine, likely from their diet[i]. The health effects of BPA have been reviewed by various researchers since 2011, including the World Health Organisation (WHO). For many potential or suspected health effects, the dose required would be much higher than human exposures. However, some effects may be associated with low levels of BPA exposure[ii]. Some reviews conclude that BPA affects female reproduction and has the potential to affect male reproduction[iii].
Investigators at the United States’ National Institute of Occupational Safety and Health (NIOSH) have investigated levels of BPA among factory workers[iv]. Levels of BPA in the workers’ urine, on their skin, and in the air were measured. The researchers found that the urinary levels were 70 times higher, on average, than in American adults overall. In addition, nearly all air and hand wipe samples had detectable levels of BPA. The BPA levels found in the workers could not be explained by diet alone, and likely occurred by inhaling and handling BPA. BPA levels also varied by job. The highest exposed job was working with molten BPA-filled wax. The urinary BPA levels found in this study are similar to those found in studies of Chinese workers in epoxy resin factories[v]. The Chinese study also found that higher BPA levels were associated with abnormal hormone levels. The NIOSH study concludes that work-related factors were associated with increased urinary levels of BPA, and that the potential for BPA-related health effects among these workers is unknown.
The European Food Safety Authority (EFSA) will re-evaluate the toxicity of BPA in 2018[vi]. The United States’ Food and Drug Administration (FDA) currently holds the view that BPA is safe at the current levels occurring in foods, and that the available information supports the safety of BPA for currently approved uses in food packaging and containers[vii].
[i] Calafat, A. M., Ye, X., Wong, L.-Y., Reidy, J. A. & Needham, L. L. Exposure of the U.S. Population to Bisphenol A and 4-tertiary-Octylphenol: 2003–2004. Environ Health Perspect 116, 39–44 (2008). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2199288/ (Accessed 23 January 2018)
[ii] Toxicological and Health Aspects of Bisphenol A. World Health Organisation, November 2010. http://apps.who.int/iris/bitstream/10665/44624/1/97892141564274_eng.pdf?ua=1 (Accessed 23 January 2018)
[iii] Peretz, J. et al. Bisphenol A and Reproductive Health: Update of Experimental and Human Evidence, 2007–2013. Environ Health Perspect 122, 775–786 (2014). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4123031/ (Accessed 23 January 2018)
[iv] Hines, C. J. et al. Urinary Bisphenol A (BPA) Concentrations among Workers in Industries that Manufacture and Use BPA in the USA. Ann Work Expo Health 61, 164–182 (2017). https://academic.oup.com/annweh/article/61/2/164/2769471 (Accessed 23 January 2018)
[v] Wang, F. et al. High urinary bisphenol A concentrations in workers and possible laboratory abnormalities. Occup Environ Med oemed-2011-100529 (2012). doi:10.1136/oemed-2011-100529 http://oem.bmj.com/content/early/2012/05/04/oemed-2011-100529.short (Accessed 23 January 2018)
[vii] Bisphenol A (BPA): Use in Food Contact Application. US Food and Drug Administration. Updated November 2014. https://www.fda.gov/newsevents/publichealthfocus/ucm064437.htm (Accessed 23 January 2018)
[viii] Freiberg, A., Schefter, C., Girbig, M., Murta, V. C. & Seidler, A. Health effects of wind turbines in working environments – a scoping review. Scandinavian Journal of Work, Environment & Health doi:10.5271/sjweh.3711 http://www.sjweh.fi/show_abstract.php?abstract_id=3711 (Accessed 25 January 2018)
[ix] Renewable Energy and Jobs Annual Review 2017. International Renewable Energy Agency. https://www.irena.org/DocumentDownloads/Publications/IRENA_RE_Jobs_Annual_Review_2017.pdf (Accessed 25 January 2018)
[x] Wind at work. Wind energy and job creation in the EU. European Wind Energy Association, January 2009. http://www.ewea.org/fileadmin/files/library/publications/reports/Wind_at_work.pdf (Accessed 25 January 2018)