Climbing chalk is used to improve your ability to hold on to the rock. There’s a lot of variation in use. Personally, I don’t use it much but I know a lot of climbers who obsessively coat their entire hands in chalk before going on any route. I hadn’t really thought much about chalk until moving to my current climbing gym. It’s a little smaller with lower ceilings and although it has filters set up to handle some of the chalk dust, the ceiling and walls still have a thin coat of chalk dust at all times. At night when the gym is busy, the loft area can get so hazy with chalk dust that it’ll give you a headache if you’re up there for more than 5 minutes. I hadn’t really noticed this much at other gyms, but regardless it got me thinking about the true costs that climbers incur from being around so much chalk dust. There is a huge and growing literature about the health costs of air pollution, so maybe some of this may apply to the chalk dust that climbers are continually inhaling?
Before even attempting to estimate the health costs of chalk-use it’s worth noting the other obvious downsides of the practice. First off, climbing chalk production requires huge and environmentally-costly mines in northeast China that causes massive air pollution as well as water contamination, “large-scale plant death, soil degradation, and reduced microbial activity.” In other words, conservation friendly climbers are directly adding to the massive environmental degradation of a foreign country. But that’s just the production side costs, the use of chalk in some our most beautiful crags across the country has massive impacts on the aesthetics of the rock.
Chalk will stay on most crags for many decades if it is shaded from the rain. We see this across many of the popular overhung sport climbing crags like Rifle, Obed, and Red River Gorge. But we will also see it many iconic and exposed lines (such as the boulder in Yosemite in the footer of this post). Sometimes the chalk will be so caked onto popular boulder routes that it will end up as graffiti on the otherwise untouched climbing lines. However, in some ways, that is a best case scenario. The common alternative is that the rain washes the climbing chalk off the rock, polluting the surrounding environment through run-off. We don’t yet have research directly attempting to assess the environmental costs of chalk on the areas surrounding crags, but we can begin to assess the magnitude of possible damage based on the number of current climbers and the already studied costs of chalk mining. For instance, there are now about 9.84 million climbers in the US and although only about one third of them actively participate in outdoor climbing that still means that around 3 million people are actively polluting popular crags with varying degrees of chalk.
We don’t have an exact idea of the amount of chalk we are polluting, but we can begin to estimate it. For reference I have always been a very conservative chalk user, I went through about one full 10 oz. bag of chalk in a year-and-a-half of outdoor climbing (I went through considerably more in the gym). I know folks who go through a few bags a year. For now I’d say a good average is about two bags, or 20 oz a year. Spread that across the 3 million active outdoor climbers and we get an estimate of nearly 4 million pounds of chalk that we introduce into the air, water, and walls of the crags we visit.
To be fair, that’s a very rough estimate and I wouldn’t defend its exactness, this is more to show that the amount of climbing pollution is likely not negligible especially when we consider the build up of chalk across the last 50 years of popular outdoor climbing. I can’t begin to actually assess the exact damage of this chalk on the environment, but I can point you to an ecological researcher who studies the impact of magnesite pollution (the main ingredient of climbing chalk) on the areas around Chinese chalk mines. The impacts are tremendous in those areas, and although the pollution will be much smaller in even the most popular climbing areas in the US that shouldn’t matter. As climbers we are supposed to be stewards of the land. We are supposed to be defending it. Instead we are polluting the environment and changing the crags for generations. I’m not sure whether I can be comfortable with that anymore.
By itself, I think there is enough environmental reason to stop using chalk, but that’s before even considering the health costs that climbers incur when constantly inhaling chalk dust in the gym. Again, despite 9.84 million people climbing every year, there hasn’t been any direct research on the exact environmental and health costs of climbing chalk dust. So we are mostly left to estimate the cost based on related research. Thankfully, though, there is a growing literature on the importance of air quality and the health effects of air pollution.
The first thing to note is that the majority of climbing chalk is not anti-dust. The best estimates of chalk-dust pollution in well-ventilated classrooms with anti-dust chalk found that 15% was still inhalable. Other research on the use of anti-dust classroom chalk found that although short-term exposure was low, persistent use poses a health threat. And unfortunately, the situation in gyms is much worse. A 2012 study on dust exposure in climbing gyms found that climbers are exposued to persistent “ high concentrations (PM(10) up to 4000 μg m(-3); PM(2.5) up to 500 μg m(-3)) of hydrated magnesium carbonate hydroxide (magnesia alba).” We hardly ever use anti-dust chalk and there are currently no requirements across most states to provide extra ventilation in climbing gyms. And since the already minimal exposure of people to anti-dust chalk in classrooms was a health threat, the continued and sometimes over-the-top-use of chalk in the gym will almost certainly have hard-to-predict long term health costs.
Many gyms get away with having minimal ventilation — a.k.a. just enough for no one to complain about hazy air. This cost would be pretty restrictive to gyms, chalk filters run at about $1900 a piece for a unit that can filter a 5000 square gymnastics gym “ with 2 uneven bars and 2 single bar trainers.” Compare that to a 5000 square foot climbing gym that could house well over 100 climbers all using chalk on walls that are covered in chalked up routes. Proper per user ventilation would suggest that each ventilation unit would be able to handle the gym’s chalk dust for 4 active users at a time. To properly handle the chalk use of an active gym per the manufacturers guidelines, we could reasonably require 10+ filters at a cost of as much as easily over $20k. But 5000 square feet is on the smaller end for climbing gyms. There are local climbing gyms that are as large as 20,000 feet. The gym I use is about 8,000 square feet and only has 2 air filters. Taken together, we are very likely spending countless hours a week in gyms that aren’t properly ventilated, surrounded by chalk that we are certainly inhaling and that is likely negatively impacting our health.
We don’t have exact estimates of the effects of chalk use on health, but we can extrapolate from research on the health costs of typical fine-particulate air pollution. For instance, we know that air pollution reduces IQ by a lot, and we know that the persistent effects of outdoor air pollution causes millions of premature deaths each year while indoor air pollution can cause as much as a few million deaths a year. In other words, the health costs of air pollution are persistent and extremely harmful and hard to detect. The nature of air pollution makes it so that we don’t easily realize their impact day-to-day, and, because of that, we don’t push for the type of harm reduction that the problem demands. And though the air pollution that accounts for the millions of yearly deaths is very different than the magnesia alba pollution climbers are exposed to, in the absence of exact evidence it’s still probably best to be extremely precautious of the possible health risks.
I think there needs to be more research on the question. I won’t pretend like I have an idea of the exact environmental and health costs of climbing chalk, but based on what we do know from the research on air pollution, it is extremely likely that climbing chalk is both bad for the environment and bad for the health of climbers.
On an individual level I think that more of us should take the example of dirtbags like Yvon Chouinard in not using chalk. At the very least we should opt for liquid climbing chalk which will be less likely to impact air quality.
On a gym level, owners should consider either banning chalk, requiring liquid chalk, or utilizing much more air filtering than is the current norm.
On a private land level, owners of popular crags (more common in the South, thinking about places like Obed and RRG) should consider restricting chalk use, employing chalk use guidelines, requiring chalk cleanup, or altogether banning chalk.
On a policy level, folks could consider banning chalk use on public lands with special consideration to areas that are environmentally fragile. State level policy makers could consider more reasonable regulations for filtering and air quality standards in climbing gyms.
On a cultural level, as a climbing community we need to be more cautious of how we are impacting our environment and other climbers. I think the biggest part of this is about rebuilding our norms about what appropriate chalk use looks like. Maybe we don’t need to outright ban chalk. Maybe we need to just use liquid chalk or provide cultural guidelines for how to appropriately use chalk in a way that doesn’t negatively affect our environment. But no matter what, as the community grows we need to be more careful about one of our most basic pieces of equipment.