More autoimmune disease if higher pollution or lower UVB - Feb 2023


UV radiation and air pollution as drivers of major autoimmune conditions

Environ Res. 2023 Feb 8;115449. doi: 10.1016/j.envres.2023.115449 PDF behind a publisher paywall
Daniele Piovani 1, Enrico Brunetta 2, Stefanos Bonovas 2

Autoimmune diseases (ADs) comprise a very heterogeneous group of chronic disorders characterized by disruptive immune responses against self-antigens (Davidson and Diamond, 2001). ADs affect about 5% of the population and include a plethora of conditions denoted by drastically different phenotypes thus showing a widely varying spectrum of morbidity and mortality (Davidson and Diamond, 2001). In this review we focus our attention mainly on five major autoimmune conditions, namely

  • type 1 diabetes mellitus (T1DM),
  • rheumatoid arthritis (RA),
  • autoimmune thyroid disorders (ATD),
  • multiple sclerosis (MS), and i
  • nflammatory bowel diseases (IBD).

Most ADs are of uncertain origins and are thought to arise from an interplay between genetic and environmental factors (Davidson and Diamond, 2001; Ramos et al., 2015; Vojdani et al., 2014; Piovani et al., 2019). Genetic susceptibility is considered to account for up to about 20–30% of the risk of ADs, whilst environmental factors are deemed responsible of the rest 70–80% (Vojdani et al., 2014). Evidence shows that the incidence and prevalence of major autoimmune conditions are rising, with some countries showing larger increases than others (Dinse et al., 2020; Walton et al., 2020; Mayer-Davis et al., 2017; Ng et al., 2017). Investigating the reasons for the increasing burden of ADs is both an opportunity to deepen our understanding on their etiology (i.e. environmental triggers) and to counteract this trend. A non-exhaustive list of environmental factors that have been extensively studied as potential drivers of major autoimmune conditions over the last decades is composed by infections, tobacco use and xenobiotics, occupational exposures (e.g. silica dust), ultraviolet (UV) rays’ exposure, factors related to hygiene, dietary patterns and single nutritional components, as well as the gut microbiome, physical activity, psychological distress, and other lifestyle factors (Piovani et al., 2019; Kivity et al., 2009; Agmon-Levin et al., 2009; Fournié et al., 2001; Khan and Wang, 2020; Salliot et al., 2020). The long-standing observation that latitude is associated with the burden of several ADs has prompted an entire area of epidemiological and experimental research that has postulated a definite role of sunlight exposure and vitamin D on the etiology of major autoimmune conditions (Mohr et al., 2008; Piovani et al., 2020; Celdir et al., 2022; Lam et al., 2020; Zipitis and Akobeng, 2008; Fitzgerald et al., 2015; Hahn et al., 2022). A historical perspective shows that most ADs were described between the 19th and 20th century and saw dramatic increases in their incidence and prevalence in the second part of the 20th century, during the third industrial revolution (Entezami et al., 2011; Landtblom et al., 2010; Kaplan and Windsor, 2021; Bach, 2002). Living in an urban environment has been associated with the incidence of major autoimmune conditions (Soon et al., 2012; Solomon et al., 1975; Southerland et al., 2022). Air pollutants may affect UVA and UVB skin absorption, thus interfering with sunrays-mediated effects on the human body (Kimlin et al., 2007; MacLaughlin et al., 1982; Jasaitis et al., 2016). Contact with air pollutants causes systemic inflammation, activates oxidative pathways, induces epigenetic alterations and modulates the function and phenotype of dendritic cells, Tregs and T-cells, which are key players in many immune-mediated diseases (Southerland et al., 2022; Fuller et al., 2022; Brunekreef and Holgate, 2002; Veldhoen et al., 2008; Zhao et al., 2019; Ferrari et al., 2019).

In this paper, we present the current evidence regarding the role of UV-mediated effects on human immunity and ADs, and how anthropic-derived air pollution may drive the rise of major autoimmune conditions through indirect (i.e. by acting on sunrays) and direct mechanisms on the human body.

Section snippets

Geographical and epidemiological patterns of major autoimmune conditions
The incidence and prevalence of several ADs show widely varying patterns across the globe (Walton et al., 2020; Mayer-Davis et al., 2017; Ng et al., 2017; Shapira et al., 2010). Type 1 diabetes, for example, shows up to a 350-fold variation in incidence across countries (Mayer-Davis et al., 2017; DIAMOND Project Group, 2006), with the highest being observed in Northern Europe and America, but also Australia and New Zealand. A very similar distribution has been observed for ADs such as MS (. . .

Impact of sunlight on human immunity
Human beings have always sought for sunlight exposure. Cave paintings tell that primitive humans appreciated and celebrated exposure to sunrays. Humans are diurnal organisms. Melatonin production occurs during the night and circadian rhythms are arranged around the fact that humans should sleep during the night and perform activities in daylight (Mead, 2008; Holick, 2004). Despite the well-known detrimental effects of excessive sun exposure, and especially the risk of skin cancer, sunlight is . . .

Epidemiologic evidence of the role of vitamin D and sunshine on autoimmune diseases
Very recently for the first time, the largest randomized controlled trial on vitamin D supplementation ever performed, the VITAL randomized trial, provided direct evidence that vitamin D is causally implicated in the development of ADs in humans (Hahn et al., 2022). The authors of the study published in the British Medical Journal enrolled 25,871 healthy participants of 50 or more years of age and allocated them randomly to vitamin D (2000 IU/day) or matched placebo, and to omega 3 fatty acids . . .

Anthropic-driven air pollution, human health and autoimmune diseases
Although the concept of autoimmunity and of the existence of ADs as a group of diseases was not theorized before the end of 1950s (Burnet, 1957), the first, later recognized, cases of the most common autoimmune conditions were mostly observed between the 19th and the 20th century, during the second industrial revolution (Entezami et al., 2011; Landtblom et al., 2010; Kaplan and Windsor, 2021). Later in time, the third industrial revolution (i.e. second part of the 20th century) was temporally. . .

Conclusions
In this paper, we have reviewed how epidemiological and experimental data converge on suggesting a decisive role of UV exposure and air pollution on major autoimmune conditions. Although the underlying mechanisms are far from being elucidated comprehensively, the current proposed paradigm suggests the presence of indirect and direct mechanisms of air pollutants in shaping the immune system and favor autoimmunity processes, hence contributing in explaining the rise of these group of diseases in

First few References

  • D.M. McCafferty et al. Inducible nitric oxide synthase plays a critical role in resolving intestinal inflammation Gastroenterology (1997)
  • A. Lanzavecchia et al. Regulation of T cell immunity by dendritic cells Cell (2001)
  • S. Kivity et al. Infections and autoimmunity--friends or foes? Trends Immunol. (2009)
  • M.G. Kimlin et al. Location and vitamin D synthesis: is the hypothesis validated by geophysical data? J. Photochem. Photobiol., B (2007)
  • C. Horton et al. Harnessing the properties of dendritic cells in the pursuit of immunological tolerance Biomed. J. (2017)
  • A. Hewagama et al. The genetics and epigenetics of autoimmune diseases J. Autoimmun. (2009)
  • M.D. Griffin et al. Gene expression profiles in dendritic cells conditioned by 1 alpha,25-dihydroxyvitamin D3 analog J. Steroid Biochem. Mol. Biol. (2004)
  • P. García-González et al. Tolerogenic dendritic cells for reprogramming of lymphocyte responses in autoimmune diseases Autoimmun. Rev. (2016)
  • R.S. Gangwar et al. Oxidative stress pathways of air pollution mediated toxicity: recent insights Redox Biol. (2020)
  • R. Fuller et al. Pollution and health: a progress update Lancet Planet. Health (2022)

All references are online - free at publisher


VitaminDWiki - 21 studies in both categories Multiple Sclerosis and UV

This list is automatically updated


VitaminDWiki - Autoimmune category contains

See also web: consensus that ~50 diseases are autoimmune, ~50 more are suspected:


VitaminDWiki Air Pollution reduces Vitamin D contains

Fact: Pollution reduces the amount of time that people are outdoors
Fact: Pollution is often associated with hot temperatures - another reason to not go outdoors
Fact: Less time outdoors results in lower Vitamin D levels
Fact: Pollution attenuates the amount of UVB getting to the skin (but by only a few percent)
Fact:The body's ability to fight Irritation/Inflammation is aided by vitamin D
Fact: All of the types of PM2.5 deaths are also associated with low vitamin D
       Most air pollutions reduce Vitamin D (PM2.5 is worst) – June 2021
Conclusion: Vitamin D supplementation helps the body fight the effects of pollution.

  • There were 60+ references in Air Pollution reduces Vitamin D page as of June 2023
  • Inhaled vitamin D might turn out to be especially good form as it goes directly to the lungs.

VitaminDWiki – Rheumatoid Arthritis category contains

115 RA items     See also Overview Rheumatoid Arthritis   Autoimmune  Inflammation   Pain - Chronic

    Highlights of RA studies in VitaminDWiki
RA worse if low Vitamin D

10 RA and Vitamin D Receptor (auto-updated)

RA Treated by Vitamin D


1882 visitors, last modified 11 Feb, 2023,
Printer Friendly Follow this page for updates