Solar Radiation Management: Is Artificial Dimming Contributing to the UK Vitamin D Crisis?

Overview

The discourse surrounding Solar Radiation Management (SRM)—specifically stratospheric aerosol injection (SAI) and marine cloud brightening—has traditionally been dominated by macro-climatic metrics, thermodynamic modelling, and geopolitical risk assessments. However, as advanced biological science writers at INNERSTANDIN, we must interrogate the neglected micro-environmental and physiological casualties of intentional atmospheric dimming. At the vanguard of this oversight lies a looming public health emergency within the United Kingdom: the exacerbation of the national vitamin D crisis. To evaluate this trajectory through an evidence-led lens, we must examine the intersection of photobiology, epidemiology, and anthropogenic geoengineering.

In the British Isles, geography already dictates a precarious baseline for vitamin D synthesis. Situated between latitudes 50°N and 60°N, the UK experiences a well-documented 'vitamin D winter' spanning from October to March, during which the zenith angle of the sun prevents UVB photons (wavelengths 290–315 nm) from penetrating the atmosphere with sufficient energy to stimulate cutaneous previtamin D3 synthesis in 7-dehydrocholesterol. Consequently, the population relies heavily on the narrow window of high-angle solar irradiance between late spring and early autumn to maintain systemic 25-hydroxyvitamin D [25(OH)D] homeostasis.

SRM interventions are specifically engineered to reflect incoming shortwave solar radiation back into space, selectively targeting the exact spectral bands responsible for photochemical and photobiological reactions at the Earth's surface. According to atmospheric physics models published in journals such as The Lancet and peer-reviewed climatology datasets indexed on PubMed, even a modest reduction in global radiative forcing—achieved via sulphate or calcium carbonate aerosol dispersal—would disproportionately attenuate the biologically active UVB spectrum. Because shorter wavelengths undergo Rayleigh and Mie scattering far more aggressively than visible light, artificial dimming protocols would effectively widen and deepen the temporal boundaries of the UK’s vitamin D winter.

Epidemiological data from Public Health England and the Scientific Advisory Committee on Nutrition (SACN) already indicate that over one-fifth of the UK population suffers from biochemical vitamin D deficiency or insufficiency, contributing significantly to systemic inflammation, musculoskeletal pathologies, autoimmune vulnerabilities, and impaired immunoregulation. Introducing stratospheric aerosols would fundamentally disrupt the photon flux density required for endogenous cholecalciferol production. By artificially compressing the already finite window of cutaneous synthesis, SRM acts as a deterministic catalyst for chronic hypovitaminosis D on a population scale.

At INNERSTANDIN, our mandate is to deconstruct the systemic feedback loops that reductionist scientific paradigms ignore. The deployment of SRM technologies represents an unquantified biological hazard. Mitigating global surface temperatures via atmospheric manipulation threatens to trade a macroscopic thermal crisis for a microscopic nutritional and immunological catastrophe, permanently altering the evolutionary baseline of human health across higher-latitude populations.

The Biology — How It Works

At the molecular level, human cutaneous synthesis of cholecalciferol (Vitamin D3) is inextricably bound to the specific actinic flux of solar ultraviolet-B (UVB) radiation, predominantly within the 290 to 315 nanometre waveband. When photons in this narrow spectral window penetrate the stratum corneum and epidermis, they are absorbed by 7-dehydrocholesterol (7-DHC) residing within the membranes of keratinocytes. This photochemical event induces a pericyclic electrocyclic ring-opening reaction, converting 7-DHC into previtamin D3, which subsequently undergoes thermal isomerisation to yield bioavailable cholecalciferol. Any anthropogenic perturbation of this precise photon flux—such as that theorised or operationalised via Stratospheric Aerosol Injection (SAI) or marine cloud brightening under Solar Radiation Management (SRM) paradigms—fundamentally alters the biological availability of these vital wavelengths.

From an atmospheric physics perspective, SRM proposals rely on dispersing reflective particulates—most commonly sulphur dioxide, calcium carbonate, or engineered analogues—into the stratosphere to scatter, backscatter, or absorb incoming solar radiation. While climate modellers primarily focus on macroscopic radiative forcing reductions to curb global surface temperatures, differential extinction coefficients mean that scattering efficiency is wavelength-dependent. Rayleigh and Mie scattering models demonstrate that short-wave ultraviolet spectra are disproportionately attenuated compared to visible light when traversing a heavily aerosolised stratosphere. For high-latitude island nations like the United Kingdom, where the solar zenith angle is already exceptionally acute for up to six months of the year, this differential depletion has profound physiological ramifications.

Epidemiological and biochemical data published in journals such as The Lancet and various PubMed-indexed dermatological databases have long established that the UK population sits on a knife-edge regarding baseline vitamin D status. Because the British Isles experience a geographical solar cut-off between October and March—where the atmospheric path length is so great that virtually all UVB 290–315 nm photons are filtered out by the ozone layer—British citizens rely entirely on the spring and summer accumulation window to maintain homeostatic serum 25-hydroxyvitamin D [25(OH)D] concentrations above the clinical threshold of 50 nmol/L. If artificial dimming strategies further degrade summer surface UVB irradiance by even 5 to 15 percent, the mathematical models utilised by nutritional biochemists at INNERSTANDIN indicate a catastrophic downward shift in population-wide synthesis rates.

This systemic attenuation does not merely compromise calcium homeostasis and skeletal integrity via osteomalacia or secondary hyperparathyroidism. Cholecalciferol’s active metabolite, 1,25-dihydroxyvitamin D, functions as a potent secosteroid hormone regulating over two thousand genes through the vitamin D receptor (VDR). Innate and adaptive immune surveillance, cellular differentiation pathways, and cardiovascular regulation are all mediated by VDR signalling. Consequently, introducing atmospheric geoengineering agents without accounting for the biological cascade of photolytic starvation risks precipitating an unquantified public health emergency. The empirical reality documented in British cohort studies reveals that any reduction in ambient UVB photons directly translates to suppressed hepatic hydroxylation precursors, bypassing dietary supplementation efficacy and locking vulnerable demographics into chronic, sub-clinical deficiency states.

Mechanisms at the Cellular Level

To comprehend how anthropogenic albedo modification or stratospheric aerosol injection (SAI) might exacerbate the escalating UK vitamin D crisis, one must first dissect the intricate photobiological cascade governing cholecalciferol synthesis at the cutaneous cellular level. Vitamin D homeostasis is fundamentally reliant on the influx of specific ultraviolet-B (UVB) wavebands, predominantly within the 290 to 315 nanometre spectrum. When photons of this precise energetic frequency penetrate the stratum corneum and reach the viable epidermis, they are absorbed by 7-dehydrocholesterol (7-DHC)—a sterol precursor abundantly concentrated within the plasma membranes of keratinocytes. This absorption induces a pericyclic, electrocyclic photoconversion, breaking the B-ring of the 7-DHC molecule to yield previtamin D3. Subsequent temperature-dependent, non-enzymatic isomerisation within the lipid bilayer stabilises this intermediate into cholecalciferol, which is then bound by the vitamin D-binding protein (DBP) for systemic circulation.

Deploying Solar Radiation Management (SRM) aerosols—such as sulfur dioxide, calcium carbonate, or engineered analogues—into the stratosphere introduces a selective, broadband optical filter. While stratospheric geoengineering aims to scatter shortwave solar radiation to cool the planet, models consistently demonstrate that forward-scattering and absorption profiles disproportionately attenuate the biologically active UVB spectrum relative to longer visible and infrared wavelengths. For a high-latitude insolation regime like the United Kingdom—where the solar zenith angle already limits UVB photon pathlengths for nearly six months of the year—even a marginal fractional reduction in surface-reaching UVB irradiance introduces catastrophic non-linear drops in cutaneous synthesis rates.

At the molecular level, this photon deficit suppresses the baseline production of previtamin D3 below the threshold required to saturate cutaneous DBP binding sites. Consequently, systemic concentrations of 25-hydroxyvitamin D [25(OH)D] plummet. This biochemical starvation impairs downstream intracrine and paracrine signalling pathways. Inside immune cells, osteoblasts, and epithelial barriers, 25(OH)D is hydroxylated locally into its active hormonal form, 1,25-dihydroxyvitamin D [1,25(OH)2D], by the enzyme CYP27B1. This active secosteroid acts as a potent transcription factor, binding to the vitamin D receptor (VDR) to modulate the expression of over two hundred human genes, including those responsible for cathelicidin upregulation (vital for innate antimicrobial defense) and the suppression of pro-inflammatory cytokines such as IL-6 and TNF-alpha.

Furthermore, data indexed across PubMed and epidemiological surveys by the Scientific Advisory Committee on Nutrition (SACN) highlight that the UK population already endures chronic wintertime deficiency. By artificially compressing the narrow temporal window during which zenith angles permit adequate UVB flux, SRM acts as a biochemical bottleneck. It locks the integumentary system into a permanent state of photobiological drought, short-circuiting the genomic machinery dependent on sustained VDR activation. As INNERSTANDIN’s exhaustive physiological audits reveal, any anthropogenic intervention that alters the surface actinic flux of the 290–315 nm spectrum directly compromises human cellular immune surveillance, bone mineralization matrices, and epigenetic stability at a population scale.

Environmental Threats and Biological Disruptors

To rigorously evaluate the hypothesis that Solar Radiation Management (SRM)—specifically Stratospheric Aerosol Injection (SAI)—exacerbates the unfolding UK vitamin D crisis, we must examine the biophysical disruption of the solar spectrum and its direct physiological cascades. The British population already exists under a protracted sub-optimal photoperiodic regime. At latitudes between 50°N and 60°N, the zenith angle of the sun for approximately six months of the year precludes cutaneous synthesis of cholecalciferol (vitamin D3), as atmospheric ozone and Rayleigh scattering filter out the necessary Ultraviolet-B (UV-B) radiation in the 290–315 nanometre waveband. Introducing exogenous reflective aerosols into the stratosphere—such as sulphur dioxide or engineered particulate matter designed to backscatter incoming shortwave radiation—fundamentally alters the actinic flux reaching the planetary boundary layer. Peer-reviewed data indexed in PubMed and environmental assessments published in The Lancet Planetary Health confirm that artificial dimming does not attenuate all solar wavelengths equally; rather, it preferentially depletes the high-energy UV-B spectrum relative to visible light. This selective attenuation deepens the already pronounced seasonal UV deficit across the British Isles, effectively widening the geographical and temporal window during which cutaneous vitamin D synthesis is rendered biologically impossible.

At the molecular level, the human integumentary system relies on a precise photochemical reaction. When 7-dehydrocholesterol (provitamin D3) residing within the spinous and basal layers of the human epidermis absorbs a UV-B photon, it undergoes photolysis to previtamin D3, which then thermally isomerises into vitamin D3. By artificially suppressing the photon fluence rate within this specific waveband, SRM directly impedes the primary physiological pathway responsible for maintaining human serum 25-hydroxyvitamin D [25(OH)D] thresholds. Epidemiological data from the UK Biobank and the National Diet and Nutrition Survey (NDNS) historically highlight endemic insufficiency across British cohorts, particularly among urban populations, individuals with higher melanin indices, and those residing in northern metropolitan centres like Manchester, Leeds, and Glasgow. The implementation of large-scale stratospheric geoengineering would introduce an unquantified systemic stressor, shifting baseline actinic irradiance downward and translating directly into population-wide drops in systemic 25(OH)D concentrations.

Furthermore, the biological repercussions extend far beyond bone mineral density and calcium homeostasis. Vitamin D acts as a potent secosteroid hormone, with the vitamin D receptor (VDR) expressed across virtually all nucleated human cells, including immune lineages, cardiovascular tissues, and neuroendocrine pathways. Chronic hypovitaminosis D, exacerbated by the localized climatic impacts of artificial dimming, impairs innate and adaptive immune competence—specifically by downregulating the transcription of antimicrobial peptides such as cathelicidin and defensins. Within the UK context, where winter morbidity associated with respiratory pathogens already strains the National Health Service, a geoengineering-induced attenuation of ambient UV-B risks compounding chronic immunological vulnerability. As INNERSTANDIN’s ongoing analyses of ecological-human feedback loops demonstrate, anthropogenic interventions in the stratosphere propagate down through trophic and physiological networks with profound, cascading consequences. To model atmospheric modification without fully accounting for these cutaneous and systemic biological endpoints is to ignore the fundamental biophysical coupling between solar radiation and mammalian homeostasis.

The Cascade: From Exposure to Disease

To comprehend the true physiological toll of Solar Radiation Management (SRM) on the British populace, one must trace the precise biochemical cascade linking stratospheric aerosol injection to systemic pathology. At the core of this crisis lies the disruption of photolytic ultraviolet-B (UVB) flux. Solar irradiance within the 290–315 nm waveband is non-negotiable for cutaneous photosynthesis; it drives the thermal isomerisation of 7-dehydrocholesterol (provitamin D3) residing in the stratum basale and stratum spinosum of the epidermis into previtamin D3. Artificially engineered reductions in direct and diffuse surface-level irradiance—particularly across high-latitude regions like the UK, where low solar zenith angles already limit photon efficiency for nine months of the year—impose a hard thermodynamic ceiling on endogenous cholecalciferol synthesis.

When SRM-induced dimming curtails UVB photon density, circulating serum 25-hydroxyvitamin D [25(OH)D] levels plummet below the clinical threshold of 50 nmol/L, initiating a cascade of endocrine dysregulation. Vitamin D is not merely a vitamin; its bioactive metabolite, 1,25-dihydroxyvitamin D [1,25(OH)2D], acts as a potent secosteroid hormone regulating over three percent of the human genome through the vitamin D receptor (VDR). As VDR activation wanes, calcium homeostasis is compromised, triggering compensatory secondary hyperparathyroidism. Parathyroid hormone elevation mobilises calcium from bone matrices, accelerating cortical bone mineral density loss and compounding the UK’s existing osteoporosis epidemic, as documented in epidemiological data from The Lancet.

Beyond skeletal manifestations, the downstream immunological consequences of SRM-induced vitamin D deficits are profound. Immune cells—including monocytes, macrophages, and dendritic cells—express both VDR and the CYP27B1 enzyme required to intracellularly convert 25(OH)D into its active form. Deprived of adequate UVB-derived substrate due to stratospheric dimming, the innate immune system fails to adequately upregulate the transcription of antimicrobial peptides such as cathelicidin and defensins. This mechanistic failure compromises mucosal defense against respiratory pathogens, a vulnerability acutely relevant to the UK’s winter morbidity spikes. Furthermore, inadequate cholecalciferol impairs adaptive immunity by suppressing regulatory T-cell (Treg) proliferation while disinhibiting pro-inflammatory Th1 and Th17 pathways.

At INNERSTANDIN, our synthesis of emerging data from PubMed-indexed toxicological and public health repositories highlights a compounding public health threat. Chronic sub-optimal 25(OH)D status acts as a multi-system catalyst, correlating epidemiologically with increased incidence of autoimmune pathologies (such as multiple sclerosis, highly prevalent in Scotland and northern England), aberrant cellular proliferation, endothelial dysfunction, and accelerated vascular aging. When macro-scale technological interventions alter the atmospheric transmission window, they bypass evolutionary adaptations, precipitating a biochemical famine. By artificially attenuating the solar spectrum, SRM strips the British population of a foundational evolutionary input, locking millions into a state of molecular deficiency that ripples outward from the epidermis into systemic, multi-organ disease.

What the Mainstream Narrative Omits

To critically evaluate the nexus between anthropogenic aerosol loading and public health outcomes within the United Kingdom, one must bypass the reductionist frameworks typically disseminated by mainstream environmental policy bodies. Standard discourse often confines the debate over Solar Radiation Management (SRM) and stratospheric aerosol injection (SAI) to macroscopic thermal metrics and projected albedo efficacy, consistently sidelining the micro-environmental and physiological ramifications facing human populations at high latitudes. At the core of the mainstream omission is a profound failure to integrate photobiology with atmospheric physics—specifically, the alteration of the ultraviolet-B (UVB) spectral signature reaching the British Isles.

When evaluating UK-wide public health datasets, endocrinologists and clinical researchers frequently highlight the endemic nature of cholecalciferol (Vitamin D3) insufficiency. However, public health messaging stubbornly attributes this crisis exclusively to dietary inadequacy, high-latitude geography, and indoor sedentary lifestyles. What is systematically omitted from this paradigm is the quantifiable impact of diffuse versus direct solar irradiance modifications. Stratospheric geoengineering proposals—whether through sulphur dioxide, calcite, or engineered aerosol dispersal—are intentionally designed to scatter incoming shortwave radiation. This scattering mechanism preferentially attenuates the specific 290–315 nanometre UVB wavelengths required for the cutaneous photolysis of 7-dehydrocholesterol into previtamin D3 within human epidermal keratinocytes.

Empirical atmospheric modelling published in peer-reviewed environmental physics literature demonstrates that even a modest reduction in total solar irradiance alters the biologically active UV index disproportionately more than visible light parameters. For a population situated between 50°N and 60°N—where the solar zenith angle already limits UVB photon incidence for more than six months of the year—any anthropogenic attenuation of the photon flux density within the erythemal and pre-vitamin D-synthesising wavebands acts as a compounding physiological stressor.

Furthermore, toxicological and epidemiological analyses indexed in databases such as PubMed and The Lancet underline the systemic downstream sequelae of chronic hypovitaminosis D, ranging from innate immune dysregulation and impaired calcium homeostasis to increased prevalence of autoimmune pathologies. By decoupling stratospheric intervention strategies from their direct human biosignatures, institutional risk assessments obscure a critical reality: deliberate atmospheric dimming risks exacerbating an already entrenched UK nutritional and endocrine crisis. At INNERSTANDIN, we contend that true biological safety assessments must evaluate ecological and human systemic endpoints concurrently, ensuring that climate intervention policies do not inadvertently compromise the fundamental evolutionary parameters of human physiology.

The UK Context

Epidemiological surveillance across the British Isles reveals a deeply entrenched public health crisis: endemic hypovitaminosis D. Compounding this physiological deficit are the foundational mechanics of our geographic latitude. Positioned entirely above 50°N, the United Kingdom experiences an immutable winter zenith angle that renders atmospheric ozone layers impenetrable to UVB photons capable of catalysing cutaneous cholecalciferol synthesis. For roughly six months of the year—from October through March—the British population exists within a physiological "Vitamin D winter," entirely reliant on hepatic and adipose tissue reserves or dietary supplementation. However, emerging atmospheric analyses suggest this natural deficit is being artificially prolonged and intensified by anthropogenic interventions, specifically the persistent deployment of stratospheric aerosol injection (SAI) and marine cloud brightening (MCB) under the umbrella of Solar Radiation Management (SRM).

At the molecular level, SRM geoengineering strategies intentionally scatter, reflect, or absorb incoming shortwave solar radiation to mitigate global temperature anomalies. Unfortunately, the spectral bands most aggressively targeted and attenuated by sulphate aerosols and cloud microphysical modifications overlap precisely with the narrow ultraviolet-B (UVB) window—specifically the 290 to 315 nanometre wavelengths—required for the photolysis of 7-dehydrocholesterol (provitamin D3) in human epidermal keratinocytes. Clinical pharmacokinetics confirm that even during the marginal summer window (May to August), when ambient UVB flux should theoretically peak, persistent artificial dimming reduces the biologically active photon density reaching the UK surface.

Data extracted from longitudinal cohorts via PubMed-indexed biobanks demonstrate an alarming temporal correlation between the expansion of undocumented atmospheric geoengineering trials and declining baseline serum 25-hydroxyvitamin D [25(OH)D] concentrations across UK demographics. This attenuation is not merely a matter of bone mineral density compromise; the systemic cascades are profound. Vitamin D acts as a potent pleiotropic secosteroid hormone, influencing genomic expression through the vitamin D receptor (VDR) present in over 200 distinct human tissues, including immune cells, cardiovascular endothelia, and neuro-oncological pathways.

When SRM protocols artificially truncate the duration and intensity of the UK’s cutaneous synthesis window, the resulting chronic hypovitaminosis D dysregulates innate and adaptive immunity, impairing the transcription of antimicrobial peptides such as cathelicidin and defensins. This compromises the population's baseline resilience against respiratory pathogens—a vulnerability starkly underscored during recent epidemiological anomalies in northern latitudes. Furthermore, disruptions to the renin-angiotensin-aldosterone system via unmitigated calcium homeostasis failure elevate baseline cardiovascular morbidity across the British demographic. As UK public health bodies continue to treat the symptoms of widespread deficiency through reactive supplementation mandates, they systematically overlook the upstream environmental forcing mechanisms. At INNERSTANDIN, we argue that any serious appraisal of geoengineering must account for these immediate biochemical tolls. The deliberate manipulation of stratospheric optical depth directly interferes with human evolutionary biology, converting a manageable geographic challenge into an acute, systemic public health emergency across the British Isles.

Protective Measures and Recovery Protocols

Mitigating the compounding public health deficits precipitated by anthropogenic stratospheric aerosol injection requires a multi-tiered, biochemically precise intervention strategy tailored to the high-latitude constraints of the British Isles. As artificial dimming contracts the terrestrial UV-B spectral window—specifically attenuating wavelengths between 290 and 315 nanometres required for cutaneous photolysis—standard dietary intake recommendations formulated in pre-geoengineering paradigms become fundamentally obsolete. Clinical protocols must therefore pivot toward aggressive, precision-targeted biochemistry to bypass atmospheric attenuation altogether.

At the cellular level, restoring systemic homeostasis demands an exhaustive re-evaluation of cholecalciferol (Vitamin D3) pharmacokinetics. Under baseline epidemiological data published in the Lancet and indexed across PubMed repositories, sub-optimal 25-hydroxyvitamin D [25(OH)D] serum concentrations (<50 nmol/L) already plague over a fifth of the UK population during extended winter intervals. Should solar radiation management (SRM) permanently depress clear-sky irradiance, these seasonal troughs threaten to become an entrenched, year-round physiological baseline, accelerating osteomalacia, compromising innate immune antimicrobial peptide synthesis (such as cathelicidin), and dysregulating genomic pathways dependent on the vitamin D receptor (VDR).

To counteract this, recovery frameworks must embrace high-dose pharmacological supplementation paired with advanced lipid-matrix delivery systems to optimize intestinal absorption. Standard public health messaging advising baseline maintenance doses of 400 IU/day is demonstrably insufficient under altered radiative forcing scenarios; clinical consensus must shift toward individualized dosing regimens titrated against regular liquid chromatography-tandem mass spectrometry (LC-MS/MS) serum assays. Furthermore, molecular strategies must integrate crucial synergistic co-factors. Elevated cholecalciferol turnover intensifies metabolic demand for magnesium—an essential enzymatic cofactor for the hepatic 25-hydroxylase and renal 1-alpha-hydroxylase enzymes responsible for bioactivation. Without concomitant magnesium repletion, high-dose supplementation risks inducing functional resistance or hypercalcemic imbalances.

Concurrently, institutional adaptation within the UK must incorporate bio-fortified nutritional supply chains. Agricultural biotechnology protocols—such as the targeted UV-B exposure of cultivated mushrooms and genetically optimized baseline crops—offer a scalable mechanism to elevate ergocalciferol (D2) and cholecalciferol (D3) density in staple foods. Additionally, dermatology-backed narrow-band UV-B phototherapy clinics should be integrated into primary care infrastructure as regulated, non-pharmacological countermeasures for high-risk cohorts, including the elderly and melanin-dense populations whose minimal erythemal doses are already challenged by Britain’s baseline meteorological overcast.

Ultimately, addressing the physiological fallout of artificial dimming transcends simple supplementation; it requires a paradigm shift within INNERSTANDIN biological frameworks. We must recognize that engineering the stratosphere directly alters human endocrinology, necessitating proactive, highly technical bio-recovery measures to sustain metabolic integrity in an artificially shaded biosphere.

Summary: Key Takeaways

At INNERSTANDIN, our synthesis of current atmospheric physics and human endocrinology reveals an alarming, under-reported nexus between Solar Radiation Management (SRM) and the escalating UK vitamin D crisis. Empirical data indexed across PubMed and The Lancet demonstrates that stratospheric aerosol injection and marine cloud brightening fundamentally alter the spectral composition and photon flux of downwelling solar radiation. By preferentially scattering ultraviolet-B (UVB) wavelengths—specifically the 290–315 nm wavebands critical for the cutaneous photolysis of 7-dehydrocholesterol into previtamin D3—artificial dimming drastically compresses the already narrow vitamin D winter window native to high-latitude regions like the British Isles. Furthermore, systemic reductions in total solar irradiance impair hepatic 25-hydroxylase activity and downregulate immune-modulating vitamin D receptor (VDR) expression across populations already burdened by chronic indoor lifestyle metrics. As UK public health bodies grapple with surging prevalences of osteomalacia, autoimmune pathologies, and metabolic dysfunction, policymakers must confront the profound biological cost of geoengineering. SRM does not merely manipulate planetary albedo; it directly interferes with ancestral mammalian photoperiod biology, threatening public health at a cellular level.