The Elements

From your home to the planet itself, environmental exposure shapes who and what you become. The five elemental exposures that govern your daily physiology are light, air, water, soil and materials, and electromagnetic fields. The first four have generated decades of robust environmental health science. The fifth has generated decades of contested claims, some of which are supported by evidence and many of which are not. We’re going to do our best below to cover what’s known, what’s reasonable, and what crosses into wellness mythology.

A general note: The popular environmental wellness literature has a recurring problem: it mixes well-supported environmental health science with speculative claims drawn from a small number of fringe researchers, presents both with similar confidence, and produces readers who can no longer tell the difference. Where the evidence is robust, it says so. Where the evidence is mixed or contested, it says that too. Where popular sources have outrun the evidence, it names which sources and where they went wrong. However, I still have my own opinions that may go against the grain.  

I. Light

Of the five elemental exposures, light has the best evidence base. The circadian biology that connects retinal light input to almost every aspect of physiology is covered in detail in Sleep & Circadian Rhythm and won’t be re-covered here. The relevant points for environmental health:

• Morning light exposure is one of the most reliable interventions in environmental medicine: The work of Charles Czeisler at Harvard, Russell Foster at Oxford, and others has established that bright morning light exposure (ideally outdoor sunlight, but indoor bright light works partially) anchors the circadian rhythm, increases evening melatonin onset, improves sleep quality, and shifts mood positively. The intervention costs nothing, has near-zero side effects, and produces measurable physiological benefit within days.
• Evening artificial light produces harm at typical modern exposure levels: Blue-enriched light from screens, overhead LEDs, street lights, and bright indoor lighting in the hours before bed delays melatonin onset, fragments sleep architecture, and over years contributes to the metabolic and mood disturbances associated with circadian disruption. The 2015 meta-analysis by Touitou, Reinberg, and Touitou consolidated the evidence across 85 studies and found that night-time artificial light exposure is a risk factor for breast cancer, sleep disruption, and circadian dysfunction across psychological, cardiovascular, and metabolic domains.
• LED-specific concerns warrant calibration: The popular wellness literature on LEDs makes claims at varying levels of empirical support. The well-supported claims: LEDs typically emit more blue-wavelength light than incandescent bulbs, which suppresses melatonin if used in the evening. The contested claims: LED flicker causing retinal damage at typical residential exposure, LEDs containing toxic heavy metals at concentrations that pose meaningful health risk, and LEDs causing the specific cascade of symptoms (headaches, poor eyesight, brain fog, lack of focus) attributed to them in some popular sources. The research on LED flicker exists, but the magnitude of effect at typical exposure is contested. The heavy metals claim is true for manufacturing waste streams, but doesn’t translate to a meaningful exposure for users of intact bulbs. That doesn’t mean you should eat them, though. 
• The mTOR/AMPK seasonal framing: Some popular literature articulates an mTOR (growth pathway, activated by light and feeding) versus AMPK (energy efficiency pathway, activated by darkness and fasting) seasonal cycle.The clinical translation to “constant artificial light produces chronic mTOR activation that drives cancer and shortened lifespan” is iffy. mTOR signalling is regulated by many inputs (nutrients, growth factors, stress, exercise), and the contribution of light to overall mTOR activity in modern humans is one factor among many. The framing is useful as a directional intuition (light and darkness both affect health), but should not be taken as a quantitative claim about cancer risk from indoor lighting.
• Practical interventions: Morning sunlight within an hour of waking; reduced bright artificial light after sunset; blue-blocking glasses or screen filters in the evening if screens are unavoidable; warm-spectrum lighting at eye level or lower at home in the evening; dark bedroom for sleep.

II. Air

The epidemiology of air pollution is among the more robust bodies of environmental health science. Particulate matter exposure (especially PM2.5, fine particles small enough to penetrate deep into lung tissue) causes cardiovascular and respiratory mortality across populations.

• The foundational research: C. Arden Pope III and Douglas Dockery’s “Six Cities Study,” published in the New England Journal of Medicine in 1993, established the link between long-term PM2.5 exposure and all-cause mortality in US cities. Subsequent decades of replication and refinement have made air pollution one of the most thoroughly documented environmental health risks. The Global Burden of Disease research consortium, including work by Jos Lelieveld, Michael Brauer, Richard Burnett, and colleagues, estimates that ambient air pollution contributes to several million premature deaths annually worldwide.
• Pregnant exposure and child development: Air pollution during pregnancy is associated with preterm birth, lower birth weight, higher rates of childhood asthma, and lower cognitive outcomes in offspring. A 2018 study reported globally that the same air pollution producing cognitive decline now affects approximately 95% of the world’s population.
• Indoor air pollution: Most people in industrialised societies spend 80–90% of their time indoors, and indoor air is often more polluted than outdoor air. Indoor pollutants include particles from cooking (particularly gas combustion), volatile organic compounds (VOCs) from building materials, paint, carpeting, furniture, and personal care products, mould spores in humid environments, formaldehyde and other off-gassed chemicals, and accumulated pollutants from poor ventilation. The World Health Organisation has published guidelines on indoor air quality that establish indoor pollution as a meaningful health concern across both low-income (cooking smoke) and high-income (off-gassing, mould) contexts.
• Exercise and air pollution: A specific concern for people who exercise outdoors in polluted environments: exercise increases ventilation rate by 10–20 times resting, meaning pollutant intake increases proportionally. The University of Edinburgh research cited in some popular wellness sources found that healthy subjects exercising while exposed to diesel exhaust at busy-highway levels showed reduced blood vessel function and reduced clot-dissolving capacity, suggesting that exercising along polluted roads carries a measurable cardiovascular cost. A 2010 Dutch epidemiological analysis estimated that the cardiovascular and respiratory cost of cycling in polluted cities reduced life expectancy by 0.8 to 40 days, while the exercise benefits added 3 to 14 months. The net was strongly positive: outdoor exercise in polluted air beats no exercise.
• Indoor gym air quality: Has been documented as poor. A study in Building and Environment found elevated CO₂, formaldehyde, VOCs, and particulate matter in indoor fitness facilities, along with mould issues in moist areas like locker rooms, pool areas, and saunas. Over 80% of gyms studied exceeded acceptable VOC levels.
• Mould as serious indoor exposure: Indoor mould exposure has graduated from contested to well-supported in the clinical literature. The Institute of Medicine’s 2004 report Damp Indoor Spaces and Health established the link between damp indoor environments and respiratory symptoms. Subsequent work has documented mycotoxin-mediated effects on mitochondrial function, immune regulation, and neurological symptoms in susceptible individuals. The Shoemaker protocol (developed by Ritchie Shoemaker for chronic inflammatory response syndrome from biotoxin exposure) is used by some clinicians; its specific diagnostic and treatment claims are contested in mainstream medicine, but the underlying recognition that some individuals have severe responses to mould exposure is increasingly accepted.
• Why outdoor exercise still wins: The body adapts well to varied environmental inputs. Cold air, warm air, sunshine, wind, rain, and the rest produce hormetic stress that builds resilience. A 2013 review in the Journal of Physiological Anthropology, “Natural Environments, Ancestral Diets, and Microbial Ecology,” documented the higher rates of immune-related diseases, anxiety, and depression in over-sanitised populations and the protective effects of early-life microbial exposure. The cumulative case for outdoor time covers air quality, microbial exposure, light, movement, and mood. Even in polluted cities, the net effect of outdoor exercise on health is positive.

III. Water

Water is where the popular wellness literature departs most sharply from mainstream science. The section below distinguishes the well-supported concerns from the contested popular claims.

Fluoride

Two things are simultaneously true:

• The dental caries benefit at typical fluoridation levels is well-supported: The 2015 Cochrane review on water fluoridation found that fluoridation reduces childhood dental caries.
• Higher-exposure neurodevelopmental effects are now also documented: The US National Toxicology Program’s 2024 monograph found moderate confidence that fluoride exposure above 1.5 mg/L is associated with lower IQ in children. US municipal water fluoridation is typically at 0.7 mg/L, below this threshold. Some natural groundwater sources contain fluoride at higher levels. The picture: typical municipal fluoridation appears to be below the level of documented neurodevelopmental concern, but exposure from other sources (toothpaste swallowed by children, naturally high-fluoride groundwater, fluoride-rich teas, industrial exposure) can add up. The reasonable position is to use fluoride toothpaste for dental health, avoid swallowing it, avoid fluoridated municipal water if that’s your source, and be aware that very high fluoride exposure (above 1.5 mg/L cumulative) does appear to carry developmental cost.

In my opinion, we shouldn’t need our water fluoridated. If the goal is to support our dental health, give it as a mouthwash and don’t force us to drink it.  

Chlorine and Disinfection Byproducts

Municipal chlorination of drinking water is considered one of the great public health achievements of the twentieth century. Waterborne disease was a leading cause of death before disinfection became standard. The trade-off: chlorine reacts with organic matter in water to produce disinfection byproducts (DBPs), particularly trihalomethanes and haloacetic acids, some of which are weakly carcinogenic at chronic exposure. The EPA regulates these byproducts at levels below documented harm.

Chlorinated municipal water is safer than unchlorinated water. Reasonable precautions include drinking-water filtration (activated carbon removes chlorine and most DBPs), shower filtration (since inhaled and skin-absorbed chloroform from hot showers is a non-trivial exposure route), and ventilated bathrooms.

The popular wellness literature sometimes presents chlorine as a primary cause of autoimmune disease, asthma, allergies, and cellular damage. The evidence for cellular damage at typical drinking water concentrations is much weaker than the popular framing suggests. Swimming in chlorinated pools is associated with elevated asthma risk in regular swimmers, particularly competitive swimmers exposed to chloramine vapours in poorly ventilated indoor facilities; this is documented. 

EZ Water, Structured Water, and Deuterium-Depleted Water

The popular literature on “structured water” or “exclusion zone water” derives largely from Gerald Pollack at the University of Washington, particularly his books The Fourth Phase of Water (2013) and his TEDx talk on cells and water. Pollack is a serious researcher whose work on water adjacent to hydrophilic surfaces describes a real phenomenon (the exclusion zone of structured water that forms near certain surfaces). The contested move is the extrapolation: Pollack and his followers claim this structured water has the chemical formula H₃O₂, is more viscous and alkaline than ordinary water, has unique electrical properties, and can be deliberately generated in your body by drinking certain waters, getting sunlight, walking barefoot, and so on.

The mainstream chemistry position is that liquid water is H₂O regardless of context, that the “fourth phase” claims have not been replicated by independent laboratories, that the proposed H₃O₂ structure is chemically problematic, and that the broader claims about structured water curing disease or producing exceptional health are not supported by the empirical literature. Pollack’s specific observations about water behaviour near hydrophilic surfaces may describe a real localised phenomenon; the broader popular framework built on these observations exceeds what the evidence supports.

• Thomas Cowan, frequently cited in this literature. His earlier work on cardiology and his books on the heart contain useful clinical observations alongside speculative framing; his recent positions place him outside mainstream consensus on most relevant questions. 
• Stephanie Seneff, also frequently cited, is an MIT computer scientist whose claims about glyphosate as the cause of autism and many other conditions have been substantively criticised by environmental scientists and epidemiologists. The glyphosate–autism causal claim is not supported by the wider literature. Glyphosate is a real environmental exposure with documented effects at high concentrations; the specific causal attributions Seneff makes go far beyond what the evidence supports.
• Deuterium-depleted water (DDW) is fringe outside specific clinical contexts. Deuterium is a real hydrogen isotope. Some experimental research has explored DDW in cancer adjunct treatment, with mixed results. The popular framing of DDW as a general health intervention for non-clinical use is not supported.

The reasonable position on water structure: drink filtered water from a reasonable source, prefer glass to plastic for storage, mineralise demineralised water with salt or trace minerals, and don’t pay for “structured water” devices.

My take on this topic is that, regardless of whether glyphosate causes autism or not, it is a probable carcinogen and should be cleaned off our fruits and vegetables with filtered water before consumption. Arguing about the semantics is pointless. 

Per- and Polyfluoroalkyl Substances (PFAS)

PFAS, sometimes called “forever chemicals,” are a class of synthetic chemicals used in waterproof fabrics, nonstick cookware, food packaging, and many industrial applications. They persist in the environment essentially indefinitely and accumulate in human tissue. Documented health effects include immune dysfunction, thyroid disorders, certain cancers, and developmental effects. PFAS in sparkling water and bottled water have been documented at concerning levels in some products. This is one of the genuinely concerning contemporary water contamination issues that the popular wellness literature has been correct about. Reverse osmosis filtration removes most PFAS.

Heavy Metals in Water

Lead in drinking water, particularly in older infrastructure with lead pipes or lead solder, remains a real public health concern. The Flint, Michigan crisis brought attention to a problem that’s more widespread than commonly recognised. Lead has no safe exposure level, particularly for children, and reducing exposure produces measurable cognitive benefit. Reverse osmosis or activated carbon filtration with lead-specific certification removes most lead.

IV. Earth and Materials

The soil microbiome that contributes to immune development, the heavy metals that accumulate from chronic low-level exposure, the contact with grounded earth that some popular literature claims has specific physiological benefits, and the building materials we live amongst.

Lead

The strongest case in environmental toxicology. Bruce Lanphear and colleagues have established across decades of research that lead exposure produces measurable cognitive impairment in children at exposures previously thought safe. No threshold of safe exposure has been identified; the dose-response curve appears to be steepest at low exposures. The 1970s removal of lead from gasoline produced one of the largest improvements in childhood cognitive development in twentieth-century public health.

Sources of contemporary lead exposure include old paint in homes built before 1978 (US) or 1965 (UK), water from lead pipes or lead-soldered plumbing, contaminated soil in urban areas with historical industrial activity, some imported ceramics and toys, and certain traditional cosmetics and medicines. Testing children’s blood lead and addressing identified sources remains one of the highest-value environmental health interventions available.

Mercury and Amalgam Dentistry

Genuinely contested. The mainstream dental position (WHO, American Dental Association, US FDA) is that mercury amalgam fillings release mercury vapour at levels far below toxicity thresholds and are safe for typical use, with some restrictions for pregnant women and young children. The holistic dentistry community disagrees, arguing that chronic low-level mercury exposure from amalgams contributes to a range of symptoms and conditions.

What’s known:

• Amalgam fillings do release mercury vapour, particularly during chewing and with hot beverages.
• Most studies have found that the level of mercury exposure from amalgams is below toxicity thresholds for most people.
• A subset of individuals appears to be more sensitive to mercury exposure, including those with certain genetic variants affecting mercury metabolism.
• Removing amalgams releases substantially more mercury vapour than leaving them in place, which is why removal protocols matter substantially. Holistic (“biological”) dentists use protocols designed to minimise removal exposure: rubber dam isolation, high-volume evacuation, supplemental oxygen, cool water spray, and air purification.
• For people considering removal, doing so without appropriate protocols may produce more exposure than leaving the amalgams in place.

If your amalgams are intact and you’re not symptomatic, the case for proactive removal is weak. If you’re considering removal, use a clinician trained in proper protocols. If I had my way, I would’ve avoided mercury fillings from the get-go. However, children don’t have a say in what is done to them.

Other Heavy Metals

Heavy metal exposure beyond amalgams comes from many sources: contaminated water, certain seafood (large predatory fish accumulate mercury through biomagnification, such as tuna, swordfish, shark, king mackerel), industrial workplace exposure, certain pesticides and herbicides, contaminated soil in urban gardens, some imported supplements and protein powders, secondhand cigarette smoke, and contaminated cookware.

Chelation: The popular wellness literature on chelation (using compounds to bind and remove heavy metals from the body) deserves careful consideration. Medical chelation under clinical supervision is appropriate for confirmed acute heavy metal poisoning and follows specific protocols. Self-administered chelation using oral chelators, IV chelation in non-clinical contexts, or “natural chelation” supplements is not supported by evidence and carries genuine risk. Chelators bind essential minerals (zinc, copper, magnesium) along with heavy metals, can redistribute mobilised metals to sensitive tissues like the brain, and can produce serious adverse effects without proper monitoring. So don’t go and swallow a bottle of charcoal willy nilly. 

The reasonable position on heavy metal exposure: reduce intake (filter water, eat smaller fish, avoid contaminated soils, check supplements for third-party testing), let the body’s own detoxification pathways handle gradual elimination, and pursue clinical chelation only under medical supervision for confirmed acute poisoning.

Soil Contact and the Microbiome

Contact with soil microbes during early development has well-documented effects on immune system maturation. The hygiene hypothesis and its successor frameworks are covered in detail in Clean Freak or Booger Eater?

Children raised on farms have lower rates of allergic and autoimmune disease than children raised in urban or sanitised environments. The protective effect appears to be mediated through exposure to diverse environmental microbes during the window of immune system development. Adult contact with soil microbes is less well-studied but plausibly contributes to skin and gut microbiome diversity.

Grounding (Earthing)

The popular literature on grounding, developed largely by Clinton Ober and synthesised in the 2010 book Earthing, claims that direct contact between the skin and the earth’s surface allows electron transfer from earth to body, producing measurable physiological benefits including reduced inflammation, improved sleep, reduced pain, and better cardiovascular function.

What’s known:

• The earth does carry a negative electrical charge.
• Bare-foot contact with the earth can produce measurable changes in the electrical potential between body and ground.
• Small studies have reported various physiological correlates of grounding (changes in cortisol, inflammation markers, sleep parameters).
• Most published grounding research is from a small group of authors with commercial interests in grounding products, and independent replication is limited.
• The mechanism proposed (electron transfer reducing inflammation via free radical neutralisation) is biologically plausible but not well-established at the magnitudes claimed.

Barefoot contact with grass, sand, or earth is enjoyable and free, doesn’t require expensive grounding mats or sheets, has plausible biological correlates, and almost certainly contributes to wellbeing through multiple non-electrical pathways (movement, sensory stimulation, time outdoors, mood effects). The specific electron-transfer-as-medicine framing is not robustly established. Grounding mats and sheets are not high-value purchases unless the underlying enjoyment of using them sustains your engagement with the broader practices.

Radiation

Brief, since the popular treatment of this topic substantially conflates different radiation types. Ionising radiation (from medical X-rays, CT scans, radon exposure, nuclear accidents) is well-established as harmful at sufficient doses and follows reasonably well-understood dose-response curves. Background environmental ionising radiation varies by location (radon being the most relevant residential exposure in many regions) and warrants testing in basements and ground floors in radon-prone areas.

Non-ionising radiation (visible light, infrared, microwave, radiofrequency) operates by different mechanisms and is covered in the EMF section below.

Iodine is a real protective factor for the thyroid against radioactive iodine exposure (the primary thyroid risk after nuclear accidents). For background population exposure, ensuring adequate dietary iodine (from sea vegetables, seafood, iodised salt) is reasonable. The popular wellness literature sometimes recommends high-dose iodine supplementation for general “detoxification” purposes; this is not supported and can produce its own thyroid problems.

V. Electromagnetic Fields

The most contested area in environmental wellness. The honest picture is genuinely complicated, and both the dismissive mainstream framing (“EMFs are nothing, ignore them”) and the alarmist popular framing (“EMFs are causing widespread biological damage”) miss something.

What’s Empirically Established

• The WHO/IARC 2011 classification: In 2011, the International Agency for Research on Cancer classified radiofrequency electromagnetic fields (the kind emitted by mobile phones and wireless networks) as Group 2B, “possibly carcinogenic to humans.” This classification reflected limited evidence in humans (particularly the INTERPHONE and Hardell studies showing elevated glioma risk in heavy long-term mobile phone users) and inadequate evidence in animals. Group 2B is the same category as pickled vegetables, aloe vera extract, and coffee at certain temperatures. It does not mean “confirmed carcinogen.” It means “there is some evidence that this might cause cancer in some circumstances, and more research is needed.”
• The NTP rodent studies: The US National Toxicology Program completed a multi-year, multi-million-dollar study on cell phone radiation effects in rats and mice, published in 2018. The study found “clear evidence” of malignant heart tumours (schwannomas) in male rats exposed to high doses of 2G/3G cellular signal across their lifespan, and “some evidence” of brain and adrenal tumours. The exposures were far higher than typical human cell phone use (whole-body rather than just the head, much longer total duration). The extrapolation from rat results at high exposure to human risk at typical use is contested. The findings are real; their relevance to typical human exposure is the open question.
• Cochrane reviews and meta-analyses on cell phone use and brain cancer in humans: Have not found consistent evidence of elevated risk at the population level over the period of cell phone adoption. If cell phones caused brain cancer at the rates some popular sources claim, brain cancer incidence in countries with high adoption rates would have risen substantially. It has not.
• Acute effects at high exposures: Exposures above ICNIRP thermal guidelines cause tissue heating and can produce demonstrable physiological effects. These exposure levels are well above typical residential and consumer-device exposures.

What’s Genuinely Contested

• Non-thermal effects: Whether RF exposure at sub-thermal levels produces biological effects through non-heating mechanisms is the central scientific debate. Henry Lai at the University of Washington has produced research suggesting non-thermal effects on DNA damage and oxidative stress. Martin Pall has proposed the voltage-gated calcium channel (VGCC) framework, arguing that RF exposure activates VGCCs and produces downstream calcium-mediated effects. Both lines of work are contested within the mainstream electromagnetic biology community. The empirical question of whether non-thermal effects exist at relevant exposure levels remains genuinely open.
• Electromagnetic hypersensitivity (EHS): A subset of individuals report symptoms (headaches, sleep disturbance, fatigue, cognitive difficulties) they attribute to EMF exposure. Provocation studies under blinded conditions have not consistently shown that EHS sufferers can identify when they’re being exposed. This doesn’t mean their symptoms aren’t real; it means the cause may not be what they think it is. The WHO position is that symptoms are real, but the causal attribution to EMF specifically is not supported. They would say that, though, wouldn’t they…
• 5G specifically: The popular literature on 5G makes claims about millimetre-wave biological effects, DNA damage, oxidative stress, and neurological harm. Some of these claims extrapolate from limited rodent or in vitro studies. The empirical research on 5G millimetre-wave biological effects is genuinely thin because the technology is recent. The reasonable position is that 5G uses different frequencies from older cellular signals, requires more closely-spaced infrastructure, and warrants empirical study rather than either dismissal or panic.

What’s Wellness Mythology

The popular EMF literature (Nicolas Pineault’s The Non-Tinfoil Guide to EMFs, Jerry Tennant’s Healing Is Voltage, Robert Becker’s The Body Electric, and similar) varies in quality. Becker’s work on bioelectricity in regeneration is foundational and serious; his later conclusions about EMF environmental harm extrapolate beyond his own data. Tennant’s voltage-of-cells claims are speculative beyond the well-established biology of cellular membrane potentials. Pineault’s book is journalism synthesising worst-case readings of the literature.

Specific claims:

• “EMFs trigger oxidative stress in your cells after five seconds.” Cited from a single study, generalised beyond its actual finding.
• “90% of cell phones exceed acceptable radiation standards” (Phonegate 2017). The Phonegate finding was that some phones tested above SAR limits under specific testing conditions that differ from manufacturer testing protocols. The interpretive disagreement is real; the popular framing overstates the consensus.
• The “30 healthy volunteers” memory test referenced in popular sources. Small single studies producing dramatic findings are not strong evidence; replication is what would establish the claim.
• The “Danish high schoolers’ plant experiment” where plants near WiFi routers grew poorly. This was a student science fair project, not peer-reviewed research, and the experimental controls were inadequate to support causal claims about WiFi effects.
  • I actually tried this experiment (n=2, mind you) and the damn plant next to the WiFi router grew bigger than the control. 
• “Schumann resonance generators” and “Blushield” devices that claim to protect against EMF damage. The biological mechanism proposed (counter-frequencies cancelling harmful frequencies) is not supported by physics or biology. These products have not been demonstrated to produce health benefits in controlled studies.
• “Sleep in a Faraday cage.” This is a fringe intervention with no empirical support for sleep improvement at typical home exposures and significant practical downsides (heat, claustrophobia, and the cage actually amplifies any RF source inside it, including phones).

The Reasonable Position

Given genuine uncertainty about non-thermal effects at sub-acute exposures, reasonable precautions are sensible without committing to wellness mythology:

• Keep cell phones away from the body when not in active use. Pocket carry continuously is a higher exposure than putting the phone on a desk.
  • Don’t carry your phone around in your pocket if you can help it. This has been shown to reduce fertility. 
• Use speakerphone, wired headphones, or air-tube headsets for calls rather than holding the phone to the head, particularly for long calls.
• Put phones on airplane mode or out of the bedroom at night. The exposure reduction is real; the sleep improvement from not being interrupted by notifications is also real.
• Prefer wired internet connections where practical. Ethernet is faster and lower-exposure than WiFi.
• Don’t keep wireless routers in bedrooms.
• For young children, minimise direct device use against the body. The developing nervous system is plausibly more sensitive to any non-thermal effects than the adult one.
• Don’t pay for grounding mats, Schumann resonators, Faraday cages, or anti-radiation pendants. These are not evidence-based interventions.
• To avoid flying radiation, choose direct routes, fly at lower altitudes (e.g., smaller regional planes), and avoid high-latitude flight paths over the poles. At the airport, bypass full-body scanners by requesting a manual pat-down or using expedited security programs.

The empirical picture may shift over the next decade as the NTP findings get replicated and 5G accumulates exposure data. The reasonable approach is to take sensible precautions, follow the evolving evidence, and avoid both the dismissive and the alarmist extremes.

Takeaway

The five elements differ substantially in how well their health effects have been characterised. Light and air pollution have decades of robust epidemiology. Water has solid evidence on some questions (lead, PFAS, fluoride dose-response) and contested popular claims on others (structured water, deuterium-depleted water). Earth and materials have clear evidence on lead and intermediate evidence on amalgam mercury. Electromagnetic fields have limited evidence of harm at acute high exposures, ongoing scientific debate about non-thermal effects at sub-acute exposures, and substantial popular literature that exceeds what the evidence supports.

A reader trying to prioritise interventions for finite time and energy should weigh effort proportional to evidence. The morning sunlight intervention costs nothing and has decades of evidence. The air quality intervention (HEPA filtration, ventilation, addressing mould) has decades of evidence. The lead testing intervention (especially with children) has decades of evidence. The water filtration intervention for lead and PFAS has solid evidence. The EMF interventions are more uncertain, and effort spent on them should be calibrated to that uncertainty rather than to the volume of popular content available about them.