The Hidden Dangers of Lead in Urban Gardens | Hacker News Reader

The Hidden Dangers of Lead in Urban Gardens

modernfarmer.com

49 pointspalidanx46 comments

Urban gardening is a great example of faux-environmentalism. It feels good, but it's not an efficient or safe way to farm. Lead contamination is one reason. Another is pure logistics. While advocates claim local food reduces "food miles" and saves resources, the amount of miles food travels to get to your plate is just a fraction of it's carbon footprint. It's much more efficient to grow food where it grows best and ship it across the world compared to growing it locally and using excess resources to grow plants in poor conditions.

If you have time, read this:

http://ntl.bts.gov/lib/15000/15100/15145/DE97763079.pdf

Otherwise, get the short version:

http://shrinkthatfootprint.com/food-miles

That said, gardening is a great hobby that shouldn't be limited to rural communities. But we need to do this safely - perhaps raised beds and a green house. And we shouldn't expect urban farming to magically solve our food needs. Even if everyone had a garden in their back yard, it wouldn't substitute the amount we grow in large farms.

The associated benefits cannot be overstated: education, beauty, community, a connection to nature, health, and most assuredly tasting better. Urban community gardens are a very worthwhile pursuit. People should be encouraged to garden with their lawns instead of using so much wasteful, non-native grass.

Long term I hope to see LED-powered warehouses for urban produce production: http://www.ledinside.com/news/2014/7/japanese_farmer_partner...

Fresh, local, efficient, and no need for pesticides.

Local urban farming is not assured to produce healthier nor tastier food. That squarely lies in the hands of the farmer. Farming is a skill; most people are not good at it.

LED powered farmhouses would be nice. But going back to the person that you commented on, now we're making energy to give to plants, instead of using the sun directly to make plants. This has the potential (especially in today's economy) to increase the carbon footprint of urban growing.

Certainly local. Fresh most likely. Efficient? Not so simple, probably not as efficient. And unless you're using GMOs that are resistant to invasive insect species, you'll still need pesticides (or lots of human hours....which severely decreases efficiency and increases cost).

> And unless you're using GMOs that are resistant to invasive insect species, you'll still need pesticides (or lots of human hours....which severely decreases efficiency and increases cost).

And good luck convincing pseudo-environmentalists that GMOs aren't evil.

"That squarely lies in the hands of the farmer. Farming is a skill;"

I want to believe. However most food production is now controlled by large corporations.

>Local urban farming is not assured to produce healthier nor tastier food. That squarely lies in the hands of the farmer. Farming is a skill; most people are not good at it.

One word: tomato. Supermarket tomatoes are grown to survive shipping. Tomatoes that you grow yourself are always more delicious.

I'm not sure why I was downvoted without an explanation. What I've stated is 100% factual: http://content.time.com/time/health/article/0,8599,2118455,0...

Because you can't generalize from a single datapoint. Tomatoes are pretty much the extreme example of this where it favors home grown plants. There's a large swath of plants where they aren't likely to be clearly better, and some where they're likely to be worse than the ones grown at scale (i.e. try growing an Apple tree from seed).

Yes but, generally speaking, urban farmers know which crops are worth growing and which ones aren't. This is why you won't find many of them attempting to grow apple trees, and a whole lot of them growing tomato and basil. Except for the occassional case of an idiot urban farmer (or, more kindly, an overly ambitious), it makes no sense to criticize urban farming on the ground that not all potential crops can be grown better in one's back yard. (Except the relatively extreme view that all agriculture can be replaced with people growing crops in their back yard -- a view that I've never heard a person espouse.)

> you'll still need pesticides (or lots of human hours.

Searching for "arduino laser insect control" doesn't come up with a lot hits (but http://en.wikipedia.org/wiki/Mosquito_laser)

...yet.

Ah, but v2 of my Arduino Mosquito laser system will get a lot more hits, I promise! (Sorry about your dog, though)

It's a more robust food source if your supply chains break down or are subject to things like oil price increases. Pests can be controlled with careful selection of plants and other factors--you don't need to douse your plants with chemicals in a lot of cases.

Most of these are closed systems - no need for pesticides or any human hours. The insects simply cannot get in.

Not saying urban gardens aren't beautiful or enlightening. But people are advocating local food grown in urban gardens for environmental and health reasons. I want to show that this is false, except in a few exceptional cases. Your link is one of them. But realize that hydroponics isn't most people's idea of urban farming. Also, there are drawbacks to the hydroponic approach (energy costs for lighting, manufacture of nutrient solution).

That said, there's a lot of potential in hydroponics, especially when you combine it with renewable energy, and I hope it continues to spread.

Grow whatever grows best in your area. Grow some of the food that doesn't grow best, but still is productive. Eat locally. Eat seasonally. Can/preserve food when you have an excess at harvest time, use cold storage liberally. Trade harvests with your neighbors to get more variety. Do that, and the issues raised in your citations are pretty much fixed.

(And while I didn't have time to read the longer article, even its abstract at top said that proper vegetable storage can resolve the issues.)

There are also more benefits to growing your own food than decreasing a carbon footprint. We put a ton of work into our family farm, to help our kids grow up to be stronger people with a better understanding of where food and other household products come from. It is hard work, and doing it purely on solar power and manual labor makes it even harder. Buying food at a grocery store would be WAY easier, but doing things the easy way isn't our goal in life.

Carbon footprints don't even make the list when we talk about the reasons why we do this.

Downvoters: do you have a problem with anyone having a different opinion?

Please don't ask for justifications for downvoting. It's a fire hose, not a paint brush.

It subtracts value from the site. It's getting really, really old. Critical thought doesn't seem welcome here.

Depends what you mean by critical thought. 'Critical' as in "expressing adverse or disapproving comments or judgments"? Nope, not welcome. 'Critical' as in "crucial or highly important", or "able to discern"? Sure, that's welcome.

The criteria for comments on HN is actually fairly demanding [https://news.ycombinator.com/newswelcome.html]. If your comment does not teach something, if it's not positive or civil, or if it's rude or dumb, it's basically supposed to be downvoted automatically.

The kinds of comments that get downvoted the most are negative ones (obviously), followed by generalized opinions, attempts at jokes, politics, and finally, meta-complaints about the discourse on HN. In doing so, it raises the value of the site for people who don't find those kind of comments deeply interesting.

On a personal level, it gets really, really old when people complain about how unfairly other people treat them. If you're getting downvoted and you don't want to be downvoted, either change your tune to get upvotes, move on to a community that likes you the way you are, or stop caring if you're downvoted or not.

I found your naming of urban gardening as "faux-environmentalism" as extremely offensive. I have checked you PDF source and it basically says that, if urban gardeners use the same methods as industrial agribusiness producers, the transport part of CO2-footprint is negligible. Which of course is technically correct, but deceptively irrelevant.

You see, is like a paper claiming that "bikes are more pollutant than cars". Then you read the article and the fine print says their working assumption is that cyclist will jerry-rig their bikes with diesel motors, effectively turning those in DIY motorcycles. No surprise that properly engineered cars manufactured in an assembly line with QA controls comes up way ahead.

That being said, your second source raises some very real concerns, like the need to eat seasonally and not to try to grow exotic stuff in your back yard.

All in all, I would qualify your original statement and say that urban gardening can turn into a form of cargo cult environmentalism, if and when the person implementing it does so without performing their due diligence before putting the first seeds on the ground.

I grow enough fruit and veg that I barter some surplus with other local growers, and the only resources I use are wastewater and composted kitchen leftovers, and the occasional bag of potting soil (like 1 a year). It's not especially efficient but I'm happy with a sub-optimal producer surplus, given the minimal investment required. The opportunity cost is likewise minimal - the space used for growing food would otherwise be filled with decorative but unproductive plants, which don't have any particular economic value for me because I'm not into flowers or having a well-manicured lawn.

Admittedly it's easy for me because living near the Oaklnd/Berkeley border I enjoy great weather, major pollutants were phased out earlier here than anywhere else in the country, I don't need to work the soil intensively to produce more than I can eat, nor am I dependent on selling food for my income. You're quite right that commercial food production involves large comparative advantages. But getting several hundred dollars' worth of food a year out of the garden suits me fine and I'm pretty sure the resultant carbon footprint is too shallow to measure.

>It's much more efficient to grow food where it grows best

Food grows best (when measured in both biomass-per-acre and biomass-per-man-hour) in forests, not monoculture fields. This becomes pretty obvious when you compare the percentage of sunlight that hits bare soil.

The only trick is to figure out how to design a forest (a non-trivial task by itself) using species that produces edible biomass, and arrange everything such that it's easy to harvest.

One example of forest gardening: https://www.youtube.com/watch?v=GFbcn06h8w4

Many thanks for the post, and the link which eventually led me to this, in which Martin Crawford also appears: https://www.youtube.com/watch?v=qVBYgg013KM

which also explains why both old (reliant on intensive manual labour) and modern farming methods (almost entirely reliant on oil) are unsustainable in the long term.

Some plants, such as ragweed, mustard, oilseed rape, sunflower, cabbage, and duckweed (for semi-aquatic gardens) are metal hyperaccumulators.

If you have contaminated soil, you can grow these plants in the contaminated soil, then remove the plants and dispose of them safely. This will take several growing seasons to bring toxic metals levels down to acceptable parameters, but it has the advantage of being extremely inexpensive. Urban soils polluted by leaded paints and vehicle exhaust will likely be usable after one or two seasons of phytoremediation, but extremely polluted waste sites could take decades, starting with a narrower range of hyperaccumulator plants that can survive the initial high levels of contamination.

Adding mustard to your regular crop rotation is also useful for pest and weed control.

Over the last 25 years lead has been phased out of paint, automobile gas and plumbing fixtures, but aviation gasoline, or "Avgas" remains leaded and is the number one source of airborne lead in the United States [0].

It frustrates me that the primary source of airborne lead stems from a mostly recreational source. Most planes that use Avgas are privately owned piston-engine/prop planes.

[0] http://ehp.niehs.nih.gov/121-a54/

There has to be some level of scale involved... I googled for lead emissions and found a nice graph showing a quarter of a billion tons in 1972 dropping to basically nothing now, around 500 tons or so.

The graph links from here

http://faculty.cua.edu/forbes/environment.htm

Shell announced lead free avgas last year. Last I heard it was undergoing regulatory approvals.

As a recreational pilot, this bugs me too. Every time I fuel the aircraft, or check fuel samples, or stick the tanks, I'm interacting with lead. I'm sure that the amount is small enough that I'll never notice any difference, but, I'd really rather not have the lead. I'm hoping for a lead-free Avgas sooner rather than later.

Keep in mind that for lead there is no minimum safe exposure limit.

It frustrates pilots as well. However, the sticking point is not the mostly recreational usage. Most of the pure recreational fleet could burn an unleaded version of the current 100LL. That wouldn't "solve" the problem though.

I'd love nothing more than to see a safe, usable, unleaded aviation fuel emerge from the morass that is the FAA approval process.

I want an unleaded replacement fuel as much for the sustainability of the necessary part that general aviation plays in the economy as for the ecological issues. There is only one chemical plant in the world that makes TEL today. We are quite possibly one significant industrial accident away from having the fuel supply disrupted.

I believe 9 candidate unleaded fuels were submitted to 1 testing avenue, though I think that the most promising fuel, G100UL, was not submitted to that testing process. Presumably GAMI (the creator of the G100UL) has some alternative certification process that they're intending. I do know that the Shell, Swift, and GAMI fuels have flown a fair amount in experimental airplanes already. That's a technical categorization. The airplane itself was probably mechanically indistinguishable from the certified airplane, but was placed into the experimental category specifically in order to test its flight characteristics with the new fuel. A certified airplane cannot legally fly on non-certified fuel (or with non-certified radios, autopilot, non-certified diesel engine, etc). Convert that same certified airplane to experimental, put the required placards on it, and you can fly it with the non-certified fuel.

To address the "why don't you just burn car gas?" question: the high-compression and/or turbo-charged engines typical in the working airplanes require an octane rating higher than currently available car gas or unleaded aviation fuel. Most (some estimates are over 80%), of the low and mid-performance piston engined airplanes could burn 94UL (the current ASTM D910 standard 100LL just without the lead added at the end of the process).

The relatively low percentage of the fleet which cannot burn 94UL is unfortunately the portion of the fleet that flies the most hours and burns the most fuel. Estimates are that this 20-25% of the fleet burns 60% or more of the fuel. These are the freight haulers, charter operators, CapeAir and other island hoppers, Alaska mail/grocery/fish/charter ops, firefighting water bombers, small business aircraft, and high-performance family airplanes. (That last category doesn't burn near as much as the planes that fly everyday on working missions, of course.)

I sympathize with the FAA a lot, as the standard (ASTM D910) for the fuel they're looking to replace is a chemical makeup standard and not a performance standard. The standard literally dictates that it contains a certain amount of tetraethyl lead (TEL), rather than dictating certain performance characteristics. Therefore, it's just as impossible to create a "standards conforming fuel without lead" as it would be to create "water without the wetness".

So, why can't we just have airports start selling the 94UL at least to those planes that can use it?

Two reasons: 1. Aviation fuel is already a low-volume fuel, and requires special handling all the way from refinery to dispensing station. If you believe that 94UL sales would only be 1/3rd of the current fuel sales, you now need a duplicative system of trucks, tanks, and dispensers for a volume of sales that's 1/3rd of the current, already low volume. The economics of that are daunting to say the least, on a per-gallon-dispensed basis. Airplanes are, by definition, mobile. If 94UL costs more than 100LL due to low-volume of sales, airplanes will fly to a field that sells 100LL. You can't readily (practically) ban the sales of 100LL to airplanes that could use 94UL, because you don't want airplanes taking off from airports that only sell 100LL with inadequate fuel and crashing from fuel exhaustion.

2. If an airport were to decide to take their existing single avgas storage tank and switch it over to 94UL, they'd be turning away 2/3rds of their business. If they decide to keep the single dispenser selling 100LL, they can sell to everyone. Again, the economics are compelling in favor of a single fuel solution for all piston airplanes.

I happen to believe in G100UL, but I'm not sure I see the clear path to getting any of them approved.

This article from 2013 makes the argument that lead in the environment is responsible for violent crime. http://www.motherjones.com/environment/2013/01/lead-crime-li...

The problem with the lead-crime hypothesis is that the cause of lead and the effect of increased crime are 'too far apart' with many intervening links in the causal chain, to paraphrase Steven Pinker [1]. He calls the hypothesis 'provocative, but far from proven.' The intervening links in the causal chain involve a lot of sub-causal links and hypotheses that are as yet, unproven.

[1] http://stevenpinker.com/files/pinker/files/pinker_comments_o...

Even if lead can't be directly related to crime, lead poisoning causes many bad things to the human body, including learning disabilities, and reducing adult brain size in children exposed.

Interesting article. I bought a CSA share with a local urban farm in St Paul and Minneapolis. I thought about soil and air contaminants when we made the purchase, but eventually decided to do it anyway. This article reassures me a bit that it's fine, especially since we always wash our veggies well.

http://dge.stanford.edu/SCOPE/SCOPE_31/SCOPE_31_2.05_Chapter...

Read the summary at the bottom for the goods. Basically, different plants absorb different amounts of cadmium, and different soils have different levels of it, and it's all influenced by whether large human developments are churning Cd into the soils nearby. Nothing that hasn't been covered in studies for the past 30 or 40 years...

while at elementary school age we were extracting lead from the old navy batteries and cables and smelt it in tin cans over open fire and made various stuff out of it - i guess new generations of children will have such fun no more :)

Kids can still have similar kinds of fun, they just have to pick a safer material. There are several low melting point metals which aren't known to be as harmful.

Plus material like this: http://www.cooks.com/recipe/p149f8qz/salt-clay-dough.html

Which is harmless and if varnished can last years (a lot of people make Christmas decorations out of it).

Future generations of children will also miss out on the "fun" of nerve damage and cognitive impairment linked to lead poisoning.

I'm all for fun and experimentation, but it's adult's jobs to keep kids from making life threatening mistakes.

In science class, we played with mercury. After school we had BB gun battles. We stood up in the front seat of my dad's pickup truck; the one with the metal dash. Bicycle helmets hadn't been invented yet. I weep for the future of children now.

//Edit: OK, people, the comment about weeping for the future of children was meant in jest! Nearly killing ourselves as kids wasn't helpful. The notion that we did all right is survivors bias.

To survive a hazard (as you, and to some extent I, did) is best of all. To suffer the constraints of protective encumbrances is next best. To die of the hazard as a child is worst.

There is a balance to be met, sure. But in choosing safetely measures we are taking out insurance. We prevent the worst, at the cost of preventing the best.

> After school we had BB gun battles.

reminded that nothing makes you run faster than an "enemy" with an air rifle with crafts-clay "bullet". Leaves nice haematoma even through wool pants :)

I'm all for the progress, yet i think abolishing BB guns/air-rifle battles isn't the one. Making sure that everybody wears safety glasses would be the one (we didn't have the ones, and that i think was unnecessary risk) Lead of course has to go.

Another - i see in the park children playing battles with "swords" which can't deliver any pain - foam wrapped by duct tape. We had "swords" we carved out of wood. They could deliver some pain, and that made the fight more lively i'd say :)

I fought battles with metal BBs. I fought battles with airsoft plastic BBs. I've never had to dig an airsoft BB out of my leg, can't say the same about metal BBs.

>I weep for the future of children now.

Yeah, it's a shame we don't kill or permanently injure our children for the sake of our own nostalgia. Because the experiences I had as a kid are the only kind of experiences worth having.

<sigh> That was mildly sarcastic on my part. I guess I overplayed it.

Did you weep for the ones who died when they went through the window of a pickup truck?

Gardens aren't the only potential vector; when we were raising chickens in out backyard in Oakland, we had an egg tested and found that its lead content was quite high. Still, visitors seemed to love that we had them, and we never received any commentary from the hens themselves.

This kind of issue is why the food safety and modernization act (or some version thereof in US) is a necessary evil.

http://www.fda.gov/Food/GuidanceRegulation/FSMA/

People on the internet (including HN) often consider this act a conspiracy by Monsanto and friends to seize control of the worlds food supply, but the simple fact is that people are regularly endangered by food they eat and there haven't been proper controls in place to address many easily preventable hazards. Just like restaurants, there needs to be some regulation and inspection of food production.

No, before you can even think it.... I'm not a paid Monsanto shill (was accused of this multiple times last time this came up here on HN) nor am I fan of big centralized seed/chemical companies. I am however a fan of safety and good sense. Just because a small producer does it doesn't mean it is necessarily better or more natural.

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