Increasing awareness of adverse effects of air pollution on health

A recent coroner’s report (20 April 2021) in relation to severe asthma in childhood has raised concerns that the “adverse effects of air pollution on health are not being sufficiently communicated to patients and their carers by medical and nursing professionals”.

The Society would like to take this opportunity to clarify that this is an important issue that we are committed to communicating effectively to members, medical students, trainees and consultants for the safe guarding of patients’ health. Here, we highlight some of the most important evidence for the risks of air pollution on the health of patients for those involved in clinical care.

Endocrinologists have been investigating and raising awareness of the effects of pollutants and endocrine-disrupting chemicals (EDCs) in causing disease for over a decade now. The Endocrine Society's first scientific statement in 2009 provided a wake-up call to the scientific community about how environmental EDCs affect health and disease, and by 2015 a substantially larger body of literature had increased our understanding of plausible mechanisms underlying EDC actions and how exposures in animals and humans—especially during development—may lay the foundations for disease later in life (1).

Thus, there is evidence for involvement of EDCs in a wide range of human disorders, including asthma and endocrine diseases, as well economic costs, and there is an urgent need for more research (2-4). 

In relation to asthma and childhood respiratory diseases we would like to highlight that:

1. EDCs which are volatile and contribute to air pollution (e.g. bisphenol A (BPA), phthalates, polychlorinated biphenyls (PCBs) and PVC) may exacerbate asthma (5, 6). This is potentially mediated by alterations in Th1/Th2 lymphocyte responses (7).
2. Endocrine disorders (e.g. hypoparathyroidism (hypocalcaemia), thyroid disease (e.g. large goitres, nodular disease) and carcinoid syndrome) can present as asthma and childhood wheeze, and awareness of these is important for making the correct diagnosis and providing appropriate treatment.
3. Air and traffic pollution may be associated with thyroid dysfunction, thyroid nodules and autoimmunity (8-10).
4. There is a strong circadian control over lung physiology and immunity (11), with acute asthma attacks often occurring in the early hours of the morning at a time when endogenous glucocorticoid levels are at their lowest, and misalignments due to modern lifestyles and shift-work are emerging as new risk factors for asthma, and these may have additive interactions to exacerbate the effects of atmospheric pollution.
5. The majority of the 8 million UK patients with asthma, are treated with glucocorticoids and a substantial number will develop Cushingoid side-effects and have suppression of their hypothalamic-pituitary-adrenal (HPA) axis which will need assessments (e.g. by Synacthen test) (12), while others will have steroid resistant asthma. The impacts of atmospheric pollution, by analogy with cigarette smoke exposure, on steroid efficacy in these patients need to be investigated.

If you would like to send any feedback on this, please contact clinical@endocrinology.org.

Professor Rajesh Thakker (President of the Society for Endocrinology and University of Oxford)
Professor Julian Davis (University of Manchester
Professor Ashley Grossman (Barts and The London School of Medicine and Dentistry and University of Oxford)
Professor Mark Gurnell (University of Cambridge)
Professor Fadil Hannan (University of Oxford)
Professor David Ray (University of Oxford)
Professor Paul Stewart (University of Leeds)
Professor Anthony Weetman (University of Sheffield)
Professor Graham Williams (Imperial College, University of London)

References:

1. Gore AC, Chappell VA, Fenton SE, Flaws JA, Nadal A, Prins GS, et al. EDC-2: The Endocrine Society's Second Scientific Statement on Endocrine-Disrupting Chemicals. Endocr Rev. 2015;36(6):E1-E150.
2. Darbre PD. Overview of air pollution and endocrine disorders. Int J Gen Med. 2018;11:191-207.
3. Kahn LG, Philippat C, Nakayama SF, Slama R, and Trasande L. Endocrine-disrupting chemicals: implications for human health. Lancet Diabetes Endocrinol. 2020;8(8):703-18.
4. Kassotis CD, Vandenberg LN, Demeneix BA, Porta M, Slama R, and Trasande L. Endocrine-disrupting chemicals: economic, regulatory, and policy implications. Lancet Diabetes Endocrinol. 2020;8(8):719-30.
5. Berger K, Eskenazi B, Balmes J, Kogut K, Holland N, Calafat AM, et al. Prenatal high molecular weight phthalates and bisphenol A, and childhood respiratory and allergic outcomes. Pediatr Allergy Immunol. 2019;30(1):36-46.
6. Parker-Lalomio M, McCann K, Piorkowski J, Freels S, and Persky VW. Prenatal exposure to polychlorinated biphenyls and asthma, eczema/hay fever, and frequent ear infections. J Asthma. 2018;55(10):1105-15.
7. Hwang YH, Paik MJ, and Yee ST. Diisononyl phthalate induces asthma via modulation of Th1/Th2 equilibrium. Toxicol Lett. 2017;272:49-59.
8. Akirov 2019 https://www.endocrinology.org/news/item/13792/Air-pollutants-associated-with-development-thyroid-nodules.
9. Benvenga S, Antonelli A, and Vita R. Thyroid nodules and thyroid autoimmunity in the context of environmental pollution. Rev Endocr Metab Disord. 2015;16(4):319-40.
10. Kim HJ, Kwon H, Yun JM, Cho B, and Park JH. Association Between Exposure to Ambient Air Pollution and Thyroid Function in Korean Adults. J Clin Endocrinol Metab. 2020;105(8).
11. Sundar IK, Yao H, Sellix MT, and Rahman I. Circadian molecular clock in lung pathophysiology. Am J Physiol Lung Cell Mol Physiol. 2015;309(10):L1056-75.
12. Grossman 2011 https://www.endocrinology.org/media/1783/11-09_syntheticacth_in_patients_with_asthma.pdf.