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Air pollution is yet another nail in the coffin regarding the health consequences of city life.

Discussion in 'Beginners Area' started by KalosKaiAgathos, Nov 3, 2018.

  1. KalosKaiAgathos

    KalosKaiAgathos New Member

    Air pollution is yet another nail in the coffin regarding the health consequences of city life.

    (As always, the emphasis is mine)


    [Relationship between surface UV radiation and air pollution in Beijing].
    Based on the data of solar radiation and air pollutants collected in Beijing, the relationship between surface ultraviolet (UV) radiation and the content of air pollutants were analyzed, using the radiative transfer model TUV4.4 (Tropospheric Ultraviolet Visible). The results show that average total ozone content is 329 DU and higher in winter and spring, lower in summer and autumn. The inverse relationship exists between ground level UV radiation and total ozone content. This study also shows that a substantial reduction (up to 50%) in the UV radiation on days with high levels of air pollution. Larger fluctuations are found in UV radiation in the summer. The effects of clouds and air pollution on UV are higher than on total solar radiation, and the reduction in UV is about twice as large as the total solar radiation values. Strong reduction in the UV radiation reaching the ground is associated with the increase of tropospheric ozone and nitrogen oxides in Beijing. The correlation coefficient between ozone concentration and decrease in UV radiation is 0.70 in the early afternoon.

    Source: https://www.ncbi.nlm.nih.gov/pubmed/29409825
    Unfortunately, there's no full text available, and that study is written in Chinese.

    However, Western studies confirm this pattern:

    The impact of air pollutants, UV exposure and geographic location on vitamin D deficiency.
    Vitamin D (VD) is an important nutrient for preventing several chronic diseases, and vitamin D deficiency (VDD) causes many diseases. Air pollution has been reported as one of the most significant factors that causes VDD. Some epidemiological studies have evaluated VDD prevalence, and presented air pollution as a potential cause of VDD. In addition, recent case studies have found that VDD is associated with air pollutants. Nearly all reports agree that air pollution affects VD levels by reducing sun exposure, especially UVB radiation. Sun exposure accounts for >90% of VD production in humans. Recent studies have demonstrated that tropospheric ozone and particulate matter are independent risks to VD levels and cause deficiency. However, obtaining comprehensive conclusions on the impact of air pollution on VDD is necessary. This study aims to review all related papers to determine how air pollution can affect VD levels.


    And yet another one:

    Low serum vitamin D-status, air pollution and obesity: A dangerous liaison.

    The aim of this review is to provide a general overview of the possible associations among the vitamin D status, air pollution and obesity. Sunlight exposure accounts in humans for more than 90 % of the production of vitamin D. Among emerging factors influencing sunlight-induced synthesis of vitamin D, prospective and observational studies proved that air pollution constitutes an independent risk factor in the pathogenesis of vitamin D hypovitaminosis. In addition, environmental pollutants can affect risk of obesity when inhaled, in combination with unhealthy diet and lifestyle. In turn, obesity is closely associated with a low vitamin D status and many possible mechanisms have been proposed to explain this association. The associations of air pollution with low vitamin D status on the hand and with obesity on the other hand, could provide a rationale for considering obesity as a further link between air pollution and low vitamin D status. In this respect, a vicious cycle could operate among low vitamin D status, air pollution, and obesity, with additive detrimental effects on cardio-metabolic risk in obese individuals. Besides vitamin D supplementation, nutrient combination, used to maximize the protective effects against air pollution, might also contribute to improve the vitamin D status by attenuating the "obesogen" effects of air pollution.

    Source: https://www.ncbi.nlm.nih.gov/pubmed/27645613

    Lastly, one more Chinese study, that, fortunately, has a full text available in English:

    The Influence of the Environment and Clothing on Human Exposure to Ultraviolet Light

    In the full text, the following graph is accompanied with different air quality indexes:

    UVA almost halves in that picture as well..

    Below the effects of different types of particulate matter on UVA and UVB penetration are visible:


    Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4414538/

    No further comment...

    labellavita likes this.
  2. KalosKaiAgathos

    KalosKaiAgathos New Member

    Another problem: another air pollutant, ozone, may also reduce vitamin D production in the skin:

    Urban tropospheric ozone increases the prevalence of vitamin D deficiency among Belgian postmenopausal women with outdoor activities during summer.
    By absorbing sunlight UVB and thereby reducing cutaneous vitamin D photosynthesis, ozone, a common urban pollutant, could cause hypovitaminosis D.

    The objective of the study was to establish the characteristics and percentage of subjects with serum 25-hydroxyvitamin D [25(OH)D] less than 75 nmol/liter among postmenopausal women engaging in outdoor activities in either Brussels or the countryside.

    This was a cross-sectional study conducted in a university research hospital.

    Among 249 women consulting for either shoulder tendonitis or lumbar spine osteoarthritis, 121 free of conditions and drugs affecting bone and calcium metabolism completed two food-frequency questionnaires within 15 d and we selected the 85 subjects with retest scores within the +/- 15% of test scores. Other parameters included sun exposure index (SEI), PTH levels, and femoral neck T-score.

    Urban residents (n = 38) and rural residents (n = 47) did not differ in mean ages, body mass indices, and vitamin D intakes. When compared with rural inhabitants, urban inhabitants were exposed to ozone levels 3 times higher, and despite a higher mean SEI (113 vs. 87; P < 0.001), they had a higher prevalence of 25(OH)D less than 75 nmol/liter (84 vs. 38%). After adjusting for SEI, 25(OH)D was 2-fold higher in rural residents, and after adjusting for 25(OH)D, SEI was 3-fold higher in urban residents. Femoral neck T-scores correlated positively with 25(OH)D and negatively with PTH levels.

    Air pollution may be a neglected risk factor for hypovitaminosis D, which is known to compromise several health outcomes. As long as 25(OH)D is greater than 75 nmol/liter, calcium intakes greater than 17.5 mmol/d are unnecessary to prevent elevations in PTH levels.

    source: https://www.ncbi.nlm.nih.gov/pubmed/18628525/

    Of course, this study did not distinguish between particulate matter and ozone, but nevertheless, ozone levels may yet be another pollutant inhibiting quantum yield (vitamin D uptake).

    Edit: found another study, this time comparing the effects of general air pollution levels:

    The impact of atmospheric pollution on vitamin D status of infants and toddlers in Delhi, India.
    To compare the vitamin D status of 34 children, 9-24 months old, living in an area of Delhi renowned for high levels of atmospheric pollution (Mori Gate), with a comparable age matched group of children from a less polluted (Gurgaon) area of the city.

    Serum concentrations of calcium, alkaline phosphatase (ALP), parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), and 1,25-dihydroxyvitamin D (1,25(OH)2D) were measured. Haze scores, regarded as a surrogate marker of solar UVB radiation reaching ground level, were measured in both areas.

    Mean 25(OH)D of children in the Mori Gate area was 12.4 (7) ng/ml, compared with 27.1 (7) ng/ml in children living in the Gurgaon area (p < 0.001). The median ALP (p < 0.05) and mean PTH (p < 0.001) concentrations were higher in children living in the Mori Gate area than in the Gurgaon area. The mean haze score in the Mori Gate area (2.1 (0.5)) was significantly lower (p < 0.05) than in the Gurgaon area (2.7 (0.4)), indicating less solar UVB reaching the ground in Mori Gate.

    We suggest that children living in areas of high atmospheric pollution are at risk of developing vitamin D deficiency rickets and should be offered vitamin D supplements.

    Source: https://www.ncbi.nlm.nih.gov/pubmed/12138058/
    The outcome in the last study is absolutely insane. The study was carried out in 2002, so in a pre 3g world, and children in the most polluted part of the city had half the vitamin D level of children in less polluted city parts.

    Non-polluted parts of the country were not even tested.
    Last edited: Nov 4, 2018
  3. KalosKaiAgathos

    KalosKaiAgathos New Member

    Surprise, surprise, air pollution can deplete certain vitamins in the skin, such as vitamin C and E:


    Unfortunately, I've not found interaction between vitamin A in the skin and air pollution (yet).


    But this result could be found:

    Airborne particle exposure and extrinsic skin aging.
    For decades, extrinsic skin aging has been known to result from chronic exposure to solar radiation and, more recently, to tobacco smoke. In this study, we have assessed the influence of air pollution on skin aging in 400 Caucasian women aged 70-80 years. Skin aging was clinically assessed by means of SCINEXA (score of intrinsic and extrinsic skin aging), a validated skin aging score. Traffic-related exposure at the place of residence was determined by traffic particle emissions and by estimation of soot in fine dust. Exposure to background particle concentration was determined by measurements of ambient particles at fixed monitoring sites. The impact of air pollution on skin aging was analyzed by linear and logistic regression and adjusted for potential confounding variables. Air pollution exposure was significantly correlated to extrinsic skin aging signs, in particular to pigment spots and less pronounced to wrinkles. An increase in soot (per 0.5 × 10(-5) per m) and particles from traffic (per 475 kg per year and square km) was associated with 20% more pigment spots on forehead and cheeks. Background particle pollution, which was measured in low residential areas of the cities without busy traffic and therefore is not directly attributable to traffic but rather to other sources of particles, was also positively correlated to pigment spots on face. These results indicate that particle pollution might influence skin aging as well.

    Source: https://www.ncbi.nlm.nih.gov/pubmed/20664556/

    So not only quantum yield is reduced, but the solar panels themselves are destroyed as well...
    Last edited: Nov 4, 2018
  4. Jack Kruse

    Jack Kruse Administrator

    ^^^^^^ Nov 2018 webinar alert folks
    KalosKaiAgathos likes this.

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