Meet Juan
Juan is a 23 years old miner, working at a very high altitude mining site in the Andes, at nearly 5000m above sea level. The air is thin, dry and cold. The atmospheric pressure is nearly half that at the sea level, and so is the oxygen in the environment. While his body has adapted to a certain extent to breath in the thin atmosphere, there is an upper limit of how much his body can adapt through increasing the oxygen carrying capacity of his blood. In fact, it is not an adaptation that gives him superhuman abilities of breathing and surviving in an atmospheric pressure nearly halfway between sea level and the vacuum of space. It is a trade-off, at a heavy cost. The blood pressure in his lungs is high in order to allow his lungs to oxygenate his body not merely to survive at such an altitude, but to let his body push itself to its physiological limit. With the exposure to silicates, and fumes from the chemical processes to refine the ore, he is often tired, fatigued and unable to sleep for many nights in a row; a direct consequence of living in an oxygen-poor environment.
Juan suffers from a condition called Chronic Mountain Sickness (Poly-Erythrocythemia (PEH), or Monge’s Disease). It is an outcome of the body’s adaptive response to survive at high altitude. The trade-off is his general health and productivity being affected by fatigue, daytime sleepiness, and pulmonary hypertension and everything that comes with it…a life cut short in terms of decades.
Juan is not alone. He is just one of the hundreds of thousands of miners working at extremely high altitude mining sites in the Andes and around the world, and sharing the same fate.
While there is no definite data available in terms of the economic impact of the effects of high altitude on mining output, there could be a direct and an indirect measure in terms of poor physiological reserve and productivity, absenteeism, fatigue, somnolence and mining accidents. Conservative estimates could be 10-15% lower productivity as compared to mining sites at lower altitudes.
Until around the mid of the last century, the issue of Chronic Mountain Sickness, or its adaptation, was limited to the permanent residents of high altitude regions of the world. This includes Tibet, Himalayas, Ethiopia, Yemen, Andes, to name a few. Over generations and millennia, the permanent residents of these regions adapted to the hypoxic atmosphere of high altitude remarkably well, but the reduced life expectancy and ill health remain a pre-dominant health issue of these regions, even today.
What is the limit of high-altitude where a long term human survival is possible? There is no easy answer. It depends upon a multitude of factors including genetics, type of occupations and daily activities, gender, and presence of pre-existing co-morbidities. The altitude sickness usually does not exist for healthy individuals below 2500m altitude. Above and beyond this limit, the oxygen in the atmosphere is low enough for the body to start making adjustments, including increasing the number of red cells (haematocrit), increasing blood pressure in the lungs (pulmonary hypertension), and modifying the anatomy and physiology of the heart itself (right ventricular hypertrophy). These changes help adjust the body to the lower partial pressure of oxygen in the environment, with a sole aim of maintaining the oxygenation of the tissues. While in itself these changes are not life limiting or debilitating (Gustavo 2024), but in the presence of co-morbidities, such as respiratory, cardiac or metabolic conditions, they do. The population impact of this can be significant. In El Alto, possibly the world’s highest metro city at an altitude of 4100 meters above sea level, overlooking La Paz, world’s highest capital 600m below, up to 35% men and 20% women (Gustavo 2024) suffer from Polyerythrocythemia or PEH (known as Chronic Mountain Sickness or Monge’s disease in different literatures), which carries significant life limiting morbidity and mortality. It makes a significant chunk of population health at those altitudes.
(La Paz at 3500m as viewed from El Alto at 4100m above sea level. The twin metropolis is one of the largest and highest cities in the world. Image credit: Jess Kraft)
Does El Alto mark the limit of human endurance in terms of high-altitude survivability in a hypoxic environment? Probably yes. But it is not the highest settlement, not even close to the record setting La Rinconada in neighbouring Peru, at a mind boggling altitude of 5100m above sea level. With a population of nearly 30,000 individuals, it is the world’s highest permanent settlement.
The altitude is so high and oxygen so poor in its thin and cold atmosphere, even locals believe this town has no future. It is generally believed that no one lives beyond fifty years in La Rinconada, give or take 5-10 years. So what makes such a large number of people live at such high altitude? It is the mining of precious metals. The gold rush is what drives humans to push to their limit and beyond.
To me, La Rinconada is more than a mining settlement. It is a nursery of ideas and a laboratory to test human physiology and potential. Halfway from the sea level to the vacuum of space, it is the next closest thing to humanity’s settlement on Mars.
(La Rinconada, Peru. At 5100m above sea level, this small town inhabited by nearly 30,000 individuals is the highest permanent settlement on Earth. Image credit: Hildegard Willer)
Discovery of precious metals in the inhospitable altitudes of Andes and the parched lands of the Atacama Desert, including gold, silver, copper and now Lithium, has created a permanent presence of humans at altitudes humans were never supposed to live. There are hundreds of mines in the Andes above an altitude of 2500m, including tens of mines at altitudes of beyond 4500m, all the way up to 5200m, fueling the global industrial progress of the modern century. In contrast to the previous practice of mostly employing indigenous or local population of the high altitude regions in the Andes, it is not sustainable for the exponential mining boom of the last few decades, and workers from lower altitude or sea level regions have to be recruited who are not genetically as well adapted to the high altitude hypoxic environments as compared to the local indigenous population. Recent decades have seen the emergence of mega-mines such as Escondida, Collahuasi, Chuquicamata, Las Bambas, Antamina, to name a few, at extreme altitudes with each mine employing over 10,000 workers. Hundreds of thousands of miners, workers and contractors work at these altitudes, facing the relatively new element of chronic hypoxia and exposed to occupational hazards of mining work while pushing their physiology to the limit. High altitude mines in the Andes are probably the harshest places to work on the face of the planet.
After thorough research, I found that contrary to my previous belief, the sensible mining industry of Latin America and the respective governments have a full acknowledgement of the problem of altitude sickness and there are measures in place to help mitigate the adverse effects of the high altitude thin and oxygen poor atmosphere on the worker’s health. There are rules and regulations in place such as the supreme decree 594 of the ministry of health of Chile, and the requirement of the miners and workers to be shuttled to lower altitudes for sleep on a daily basis. High altitude mines in Chile send their workers to sea level cities on their days off where they are mostly from and the geographical distances are not huge. Unfortunately, this is not much of a case in neighbouring Peru, Bolivia and Argentina where the geographical distances to sea level cities are much greater and the terrain is much more rugged for an easy transit.
Rotational shifts with traveling to lower altitude once every few weeks for a few days turns the highly debilitating chronic hypoxia into more favourable chronic ‘intermittent’ hypoxia, which gives a human body an opportunity to partly resolve the increased viscosity (haematocrit) of the blood and the increased blood pressure in the lungs. But this recovery is not complete and the impact of exposure to chronic hypoxia continues to accumulate.
A similar situation occurs with the flight crew who have to transition between cabin pressure at roughly 0.75 bar (equivalent to that at 2500m altitude) and 1 bar at sea level (a difference of 0.25 bar) on a daily, sometimes many times in a 24 hours cycle. This is called Acute Intermittent Hypoxia (AIH). Studies have shown that the overall health outcome in terms of Standardized Mortality Ratio (SMR) and Standardized Prevalence Ratio (SPR) for AIH in the flight-crew is no different from the general population at sea level (Aragon-Vela 2020).
And this is precisely what we want to achieve at the high altitude mining sites in Andes (and anywhere else in the world) through our Craterhab pressurized inflatable habitat system, originally designed and patented for Martian (and Lunar) environments.
A solution from space
Extraordinary problems require extraordinary solutions. Chronic hypoxia at the highest altitude mines is a problem that was never supposed to happen. But it is a continuum of human endeavour to break the ceiling and discover new horizons. And it is this trait that makes us eye on permanently settling on Mars. The human experience of living and working at the highest altitude mines will pave the way for human settlement on Mars, because this is precisely what we will be doing on the red planet.
Craterhab Technology offers solutions for both scenarios.
What are Craterhabs?
(An artistic rendition of a Craterhab base on Mars. Artwork credit: M. Akbar Hussain)
Craterhabs are the signature product of Mareekh Dynamics. These are large ultra-high tensile inflatable fabric domes, designed to withstand several bars of internal inflation pressure, to create a micro-terraformed environment inside Martian craters 50 to 500m in diameter, by creating 0.6 to 1 bar internal pressure, similar to the atmospheric pressures on Earth.
These are composed of a Dyneema or Spectra hexagonal skeletal framework, wrapped around by Aramid-carbonfiber-resin composite and silicone-polyethylene composite bilayers. The peripheries of the Craterhab continue between a circumferential concrete sandwich wall and tethered to underground concrete anchors, to withhold the dome against large inflation pressures. The entry will be through an airlock system.
Craterhabs harness the compactness of the peripheries of a Martian crater to act as a secure interface for anchoring of the inflated dome, and the depth of the crater as extra volume of precious internal habitable space for the same amount of material as for a flat surface.
(Another depiction of a Craterhab base on Mars. Artwork credit: M. Akbar Hussain)
Terrestrial application of the Craterhab Technology in high-altitude mining
The core concept is to create a pressurized environment at a very-high altitude mine, for example Collahuasi Mine in Chile or Antamina Mine in Peru; both being at 4500m above sea level. The atmospheric pressure at this altitude is barely 0.6 bar.
Craterhabs (20-50m diameter) can be installed at these sites and contain a 0.8 bar pressure (equivalent to the cabin pressure at 2500m). This creates a difference of +0.2 bar between inside and outside. Much higher pressures such as 1 bar pressure (sea-level pressure; difference = 0.4 bar) can be maintained, however maintaining a sea level pressure inside a Craterhab at 4500m altitude, will cause the body to endure +0.4 bar pressure difference. Also, sea level pressure may risk losing the acclimatization. Maintaining an internal pressure equivalent of 2500m will not only impart less stress on the dome structure, it will also preserve the acclimatization while helping him recover quicker, with no long term health consequences.
(An AI generated artwork depicting a Craterhab facility at a mining site in Chile. These Craterhabs can be anywhere from 20m to 50m in diameter and can be used as pressurized habitation units on-site at a high-altitude mining site, simulating atmospheric pressures of lower altitudes, and helping miners and workers recover from altitude sickness on daily bases. Credit: Mareekh Dynamics)
(Another AI depiction of a Craterhab facility at a mining site in Peru. In several locations, the mines are in more rugged terrains. Innovative solutions to utilize the available space may be the answer. Credit: Mareekh Dynamics)
Understanding altitude sickness at high altitude mining sites; a literature review
There are several observations and studies conducted to understand the phenomenon of chronic hypoxia among miners and workers at very high altitude mines around the globe. Here is a list of some of the journal articles and web pages discussing the problem, its implications and possible solutions.
Periodic breathing and oxygen supplementation in Chilean miners at high altitude (4200m). Moraga et. al. Respiratory Physiology and Neurobiology, Nov 2014
The number of workers in Chile working above 3500m has substantially increased since 1995.
Initial exposure to high-altitude hypoxic environments leads to AMS, physical and mental deterioration, and sleep impairment.
Oxygen supplementation equal to that of a lower altitude atmosphere helps.
This highlights the importance of creation of a simulated lower altitude atmosphere to help mitigate altitude sickness
Chilean Miners Commuting from Sea Level to 4500 m: A Prospective Study. Richalet et. al. High Altitude Medicine and Biology, 2002
Intermittent exposure to high altitude causes Chronic Intermittent Hypoxia
Haematocrit rises in CIH but not as much as Chronic permanent exposure
CIH is a relatively new mode of hypoxic exposure, distinct from acute (alpinism) and chronic (permanent residence).
At Collahuasi mine in Chile, miners work at 4600m and retract to the dormitories at 3800m for eating and sleeping.
Exposure to intermittent hypoxia prevented long term health effects and altitude sickness.
Right ventricular changes were the mainstay of cardiovascular effects of the high altitude.
Physical performance decreased over time with exposure to high altitude atmosphere.
Health Considerations for Managing Work at High Altitudes, Encyclopedia of Occupational Health and Safety, Feb 2011
Increased commercial activities between altitudes of 3500 - 6000m has resulted in an influx of workers from sea level
Quality of life at higher altitudes is less than that at sea level.
Workers from sea level regions suffer from Acute Mountain Sickness.
Prolonged severe hypoxia has a number of harmful effects on human health including reduced
Highly advantageous for workers to sleep at lower altitudes which is safe unless the transit time is too long.
Pressurized chambers or rooms were discussed.
Supplemental oxygen is also helpful.
A New Seam of ANGST, Porteous, C. Today’s Paper Dec 2001
High altitude causes dehydration, thickening of blood and a generalized deterioration.
At Collahuasi mine in Chile, the workers work at 4600m and sleep at a lower altitude of 3800m
Working and staying above 3800m carries inherent risks
BHP Billiton, which owns Escondida copper mine, the world’s largest, has a strict regime to safeguard against altitude problems, including pre-employment health checks.
Ventilatory Cycle Measurements and Loop Gain in Central Apnea in Mining Drivers Exposed to Intermittent Altitude. Castro et al. Journal of Clinical Sleep Medicine, Jan 2017
67% of the mining activities in Peru are concentrated above 2000masl
Workers work at high altitudes and return to lower altitudes to their home towns during their days off.
Three types of exposure to high altitude: Acute, Chronic and Intermittent.
High-altitude periodic breathing leads to poor sleep patterns including central sleep apnoea.
The Challenges of Mining in High-Altitude Regions; miningworld.com, 21 Aug 2024
Hypoxia is a critical concern above 8000m altitude leading to potential physical and cognitive decline.
Does intermittent exposure to high altitude increase the risk of cardiovascular disease in workers? A systematic narrative review. Aragon-Vela et al. BMJ Open Nov 2020
Working groups exposed to high-altitude hypoxic exposure are miners, soldiers and flight crew.
Flight crew are exposed to Irregular short-term intermittent hypoxia (lasting <24 hrs), and demonstrated an Standardized Mortality Ratio (SMR) and Standardized Prevalence Ratio (SPR) for cardiovascular diseases not much different to a general healthy population.
Miners and soldiers stationed at high altitude are exposed to Long-term intermittent hypoxia, majority of whom developed cardiovascular problems, including pulmonary hypertension, increased pulmonary vascular resistance, deteriorating lung function, and adverse changes in the heart anatomy.
Redefining chronic mountain sickness: insights from high-altitude research and clinical experience. Gustavo Zubieta-Calleja, De Gruyter Med Review 2024
Many of the signs and symptoms of Chronic Mountain Sickness (CMS) can also be attributed to pre-existing conditions that affect humans at lower altitudes.
Hypoxia, pulmonary hypertension, and increased haematocrit are the definite signs and symptoms attributed to CMS from prolonged exposure to high altitude.
(P.S. This article is based on my research of the altitude sickness in Andes from various resources. Due to differences in the opinions among many researchers on the subject, there may seem to be variations. Feedbacks are welcome)
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