“We need to ask more questions of our food supply, both urban and rural.”

By Eli Zigas
Grist
13 Sept 2011

Excerpt:

As someone who works on urban agricultural policy, I’m often asked, “Is city-grown food safe?” The question comes from aspiring urban gardeners and concerned eaters alike. And it seems to stem from both a fear of the known and a fear of the unknown.

First, the fear of the known: Common urban contaminants include lead, arsenic, and other heavy metals leaked into soil from old paint, leaded gasoline, modern car exhaust, and industrial land-use.

These metals are responsible for a whole host of maladies. Heavy exposure to lead, for example, can harm the nervous system and result in other developmental disabilities, especially in children.

In San Francisco, where I work, a recent study of garden soils confirmed the presence of residual lead in many parts of the city. Similar studies have taken place or are in the works in Minnesota, Chicago, and Indianapolis. They all show considerable evidence of lead in urban soil.

Read the complete article here.

Urban farming has become hugely popular in the East Bay, but lead and other heavy metals in the soil pose potential health risks. Meanwhile, there’s little consensus on what to do about it.

By Nate Seltenrich
East Bay Express
Aug 3, 2011

Excerpt:

These are the dilemmas that cities and urban gardeners now face. Yet organizations like City Slicker Farms are working hard to develop safe, practical solutions to soil contamination. Since 2005 the organization has set up 170 backyard gardens, including about 140 in West Oakland, all at no cost to the recipients. The initial step is always a soil test. While few lots exhibit truly dangerous levels, most are elevated and require some form of remediation — typically, covering the soil with mulch and growing vegetables in raised beds.

“So many backyards have lead paint in it, because lead paint was prevalent everywhere,” said executive director Barbara Finnin. “So we’re figuring out instead of digging out all the soil, how can we do that safely here?” In a two-foot-tall raised bed over an impenetrable root barrier, the risk of plant contamination is virtually eliminated, she said. Mulch as thick as six inches elsewhere in the yard helps protect children and animals from direct soil contact.

It’s a simple solution supported by urban farming celebrity Novella Carpenter, who runs Ghost Town Farms on a vacant lot in West Oakland. In her backyard, which is adjacent to a gas station, she tested and found high levels of lead. So she topped the soil with landscape fabric and mulch to protect her animals, which can bio-accumulate lead just like humans and pass them along through their meat, milk, and eggs. Yet she won’t grow any produce there. The majority of her front-yard beds are built directly atop a concrete patio that’s covered with a few inches of dirt. “It’s actually a nice thing to build on concrete,” she said — the danger of contamination is always nil.

Read the complete article here.

Looking at the soil in a vacant lot

By Melissa Iverson M.Sc. (Soil Science)
University of British Columbia – Faculty of Lands and Food Systems
2010, 39 pages

Introduction – How to Use This Guide

Have you ever walked by that vacant lot near your home, work, or school, and thought “I would love to make this place a garden!” If so, then this guide is for you!

The purpose of this guide is to help you answer some of the big questions about the environmental quality of your site. Questions like:

How can I find out if the soil is contaminated?
Is the soil deep enough for my plants to have healthy root systems?
Are there enough nutrients in the soil?
Is the site too shady for a garden?

These are important questions to answer after issues regarding site tenure, community support, and liability insurance have been addressed.

To use this site, go to the decision tree diagram on the next page. Starting at the top of the “tree”, with the box entitled: “Does the site’s history or location present a contamination risk?” Go to the corresponding chapter heading and carry out the suggested activities. These activities should provide information to help determine a “yes” or “no” answer. Proceed down the decision tree, concluding with the boxes “Garden” or “Select another garden location.”

Read the complete report here. (4 MB)

“We’re giving them the land for nothing, We certainly haven’t set aside a budget for cleaning up this land.”

By Luke Brocki
Open File
February 18, 2011

Excerpt:

The trouble with land is that it’s practically impossible to make more of it. Despite the City of Vancouver’s plans to see its flagship urban farm expand to new locations, SOLEfood farm is getting a hard lesson in real estate: the city’s few empty lots are either slated for development or are long-abandoned and contaminated industrial sites.

“Unfortunately the soils are not usable,” says seasoned farmer and author Michael Ableman, the man in charge of growing food at the social enterprise in Vancouver’s Downtown Eastside. “We cannot move forward and allow people to grow edible crops in soil that’s going to essentially poison those crops,” he says.

That’s exactly the problem at 1015 East Hastings Street, a half-acre former junkyard the city has already leased to United We Can, the parent company behind SOLEfood, with the expressed purpose of expanding the farm’s operations. As the new growing season draws near, Ableman worries the site’s grade, drainage and, above all, soil toxicity might be deal-breakers.

“I made the decision last week to walk away from that site,” he says. “They’re working had to try to resolve this, but unless the city is going to come forward and cover the cost of that mitigation, then we’re going to walk and go for another location.”

Read the complete article here.

Urban Certified Organic?

Researchers from the Department of Geophysical Science working in the area of Food and Environment at The University of Chicago are currently evaluating the application of the National Organic Standards to Urban Agriculture. The U of C team of Geoponicuns are working in collaboration with several national and international organizations, to determine and address the inherent challenges of preserving organic integrity on urban farms.

By Julia Govis:
For questions and/or comments, contact:
Email: govis@geosci.uchicago.edu

Consumer demand for organic food continues to climb according to a 2009 press release by the Organic Trade Association.(1) Growing concerns over food safety and chemical usage in conventionally raised farm products are some of the reasons cited by consumers choosing to purchase certified organic food.

Other recent trends in food production and consumer preference include “urban agriculture” and buying “locally grown”. Local food production is currently being supported and encouraged by USDA initiatives. “Urban agriculture” is being enjoyed by individuals and families through backyard and community gardens, but it is also being considered by City planners in major cities, as a potential means to offset carbon emissions and greenhouse gases.

Other recent trends in food production and consumer preference include “urban agriculture” and buying “locally grown”. Local food production is currently being supported and encouraged by USDA initiatives.(2) “Urban agriculture”(3) is being enjoyed by individuals and families through backyard and community gardens, but it is also being considered by City planners in major cities, as a potential means to offset carbon emissions and greenhouse gases. (4,5)

Undoubtedly, as urban land put into cultivation for food production increases, so too will the consumer demand that a portion of that food be grown to meet a certain level of standards, such as the level of standards currently found under the USDA/ORGANIC Label.

It would be unrealistic to assume the same set of growing standards can be applied to urban growing conditions as are currently used in rural growing conditions. There are far too many known and yet unknown potential human health threats associated with contaminated soil, air and water, specific to urban environments.

The concerns first raised by the Soil Association in 1967, (the initial international organic advocacy association) seem especially applicable as we move forward with urban food production:”The use of, or abstinence from, any particular practice should be judged by its effect on the well-being of the micro-organic life of the soil, on which the health of the consumer ultimately depends.”

Other recommended organic practices to mitigate off farm contamination of crops, for instance, the current acceptable width and depths of buffer zones, would be unrealistic, when applied to the smaller growing plots available to urban farmers. This and other standard recommendations will not directly transfer to the realities of urban growing methods and will need to be addressed in order to maintain the high level of standards American consumers have come to associate with the USDA/ORGANIC Label.

The goal of this project is to identify, test and address potential on and off farm contamination of urban farms under organic management. The final goal’s of this project include;

1.) The presentation ( by Martin and her team) to the NOSB, a set of recommendations for consideration and possible adoption to the NOP rules, specific to urban conditions.

2.) A set of standards to be incorporated into the current training program of Inspectors being trained through the International Organic Certification Association (IOIA)

3.)Finally, other cities worldwide can look to these scientifically tested standards for their own use and possibly, as internationally accepted standards, used for global trade.

1. http://www.organicnewsroom.com/2009/05/
2. http://www.usda.gov/wps/portal/knowyourfarmer
3. http://www.foodsecurity.org/urbanag.html
4. http://www.cityfarmer.org/tarathesis.html
5. http://www.ifpri.org/publication/

Implications for contaminated land risk assessment and risk management?

By Jonathan R Leake 1 , Andrew Adam-Bradford 2 and Janette E Rigby 3
1 Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
2 Department of Geography, University of Sheffield, Sheffield, UK
3 National Centre for Geocomputation, National University of Ireland Maynooth, Co. Kildare, Ireland
Environmental Health
Published: 21 December 2009

Excerpts:

Abstract

Compelling evidence of major health benefits of fruit and vegetable consumption, physical activity, and outdoor interaction with ‘greenspace’ have emerged in the past decade – all of which combine to give major potential health benefits from ‘grow-your-own’ (GYO) in urban areas. However, neither current risk assessment models nor risk management strategies for GYO in allotments and gardens give any consideration to these health benefits, despite their potential often to more than fully compensate the risks. Although urban environments are more contaminated by heavy metals, arsenic, polyaromatic hydrocarbons and dioxins than most rural agricultural areas, evidence is lacking for adverse health outcomes of GYO in UK urban areas.

Rarely do pollutants in GYO food exceed statutory limits set for commercial food, and few people obtain the majority of their food from GYO. In the UK, soil contamination thresholds triggering closure or remediation of allotment and garden sites are based on precautionary principles, generating ‘scares’ that may negatively impact public health disproportionately to the actual health risks of exposure to toxins through own-grown food. By contrast, the health benefits of GYO are a direct counterpoint to the escalating public health crisis of ‘obesity and sloth’ caused by eating an excess of saturated fats, inadequate consumption of fresh fruit and vegetables combined with a lack of exercise.

These are now amongst the most important preventable causes of illness and death. The health and wider societal benefits of ‘grow-your-own’ thus reveal a major limitation in current risk assessment methodologies which, in only considering risks, are unable to predict whether GYO on particular sites will, overall, have positive, negative, or no net effects on human health. This highlights a more general need for a new generation of risk assessment tools that also predict overall consequences for health to more effectively guide risk management in our increasingly risk-averse culture.

Conclusion

Growing your own food in urban areas has many potential health benefits which may positively improve the physical and psychological health of participants, and these health benefits may significantly offset or compensate for the apparently minor risks that follow from the higher loads of environmental pollutants in urban as compared to rural environments. The health benefits of GYO- which directly addresses some of the key national problems with diet and lifestyle- are likely to more than fully compensate risks at most sites that exceed current soil guideline values. This reveals a serious limitation in current risk assessment methodologies which, in only considering risks, are unable to assess to overall net effect of GYO on human health, and therefore may result in closure of sites that are providing significant overall health benefits to the GYO practitioners. This highlights the need to develop more sophisticated risk assessment tools that predict overall consequences for health from assessment of risk and benefits to health using a common metric and which can be built onto existing risk assessment tools such as CLEA. This will enable the individual and overall risks to health to be established to fully inform risk management decisions.

The complete paper can be read here.

Attack of the Rotten Tomatoes

By Anne Marie Chaker
Wall Street Journal
March 10, 2010

Excerpt:

The city of Baltimore replaced its flower beds in front of city hall with vegetables last year. The goal, says designer Angela Treadwell-Palmer, was to show that vegetable gardens could be attractive and to grow harvests to donate to a local soup kitchen. But the local charity reported that some crops—particularly beets, kohlrabi and eggplant—weren’t appetizing to people.

So this year, Ms. Treadwell-Palmer is redesigning the garden to grow bigger yields of fewer crops like cabbage, kale and collard greens. The garden will also have a less-fussy, more minimalist look. And in the spring, at least, not all the beds will be vegetable plots, leaving room for some tulips—and more time for gardeners to breathe. “It was hard work,” she says.

Spurred by the recession and the trendiness of locally grown produce, many people planted vegetables for the first time this past year. But rookie mistakes, combined with a particularly cruel growing season that included late blight and heavy rainfall, have many now wanting to throw in the trowel. Experienced gardeners say early spring is the perfect time to correct last year’s mistakes.

First-timers typically overlook fundamentals like light, good soil, planting time and proper spacing between plants. Also, “a lot of young people are kind of curious but don’t know the time commitment,” says Jon Traunfeld, a senior agent with the University of Maryland’s Extension service, which assists gardeners in communities statewide. Mr. Traunfeld, who specializes in fruits and vegetables, says the service was hammered with questions, logging in 1,963 phone calls and emails last year, up 47% from the year before.

See the complete article here.

Photo by Jim Richardson, National Geographic.

By Charles C. Mann
September 2008
National Geographic

By 2030, when today’s toddlers have toddlers of their own, 8.3 billion people will walk the Earth; to feed them, the UN Food and Agriculture Organization estimates, farmers will have to grow almost 30 percent more grain than they do now.

“With eight billion people, we’re going to have to start getting interested in soil,” he said. “We’re simply not going to be able to keep treating it like dirt.”

See the complete article and photos here.

“The tests were performed as part of the health department’s analysis of soil samples from all of Montreal’s nearly 100 community gardens. Beausoleil said about 30 gardens city-wide are contaminated. However, only 11 gardens have been closed – nine of them last year. The other affected gardens will be made public this year by the boroughs in which they are located, Beausoleil said.

“We can tell you right now, there is no worry for your health as a result of eating vegetables from this soil,” Monique Beausoleil, a toxicologist with the department — She explained that most of the contaminants were found in soil lower than the roots that most typical vegetables grow, so their absorption rate was very low.”

Montréal Gazette article, April 1, 2008.

Links to official tests and reports.

Montréal’s community gardening program – description, 14 page PDF.

“— a system of land use that is being practiced in metropolitan Kano will be considered. This system of land use that has been going on for centuries involves the use of stream water to irrigate land at the banks. Principal of these streams are Challawa, Getsi, Jakara and Salanta. The main objective is to produce fruits and vegetables for the consumption of the city dwellers. This system of land use has been called by Binns et al (2003), by the name urban and peri-urban agriculture (UPA).”

Complete paper can be read here.

Conclusions and Recommendations

The results have indicated that the quality of the soil for cultivation is only marginal in terms of fertility, largely caused by cultural practices that result in over utilization of the land transiting from rain-fed to irrigation agriculture.

The findings in this research have also shown that the levels of these metals in the soil has not reach a level that could cause any immediate threat as all the mean values have been found to be significantly lower than the internationally recommended values. There may however be a long term risk of concentrations rising to unwanted levels. Water quality is a major factor in determining success and safety of irrigation agriculture, and pollution of irrigated soils with heavy metals is a possibility when polluted water is being used for irrigation. Studies have already established high concentrations of many of such metals in the waters being used for irrigation in the area, which probably is a major source for the small concentrations detected in the soils, along with other sources such as fertilizer, chemicals and vehicular discharges. If current land use practices are maintained the soil could be at higher risk because of the tendency of metals to accumulate in the soil as they are hardly detoxified and they form complexes with various
substances in the soil.

Based on the findings therefore, the following recommendations are suggested;

1. Incorporation of higher levels of organic matter. The textural nature of the soil shows it to be predominantly sandy, which makes the soil susceptible to water loss. Incorporation of higher levels of organic matter may help to improve the water holding capacity of the soil, thereby reducing the need for frequent irrigation, which will further reduce the exposure of the soils to pollution source. Preferably, the organic matter to be used should be composted, which will rule out the need for decomposition within the soil environment, thereby
enhancing utilization of the minerals released by the organic matter, and helping to reduce the chances of the metals forming complexes with the organic matter.

2. Continuous monitoring of fertility situation in the soil with the aim of evaluating its quality for the land use.

3. Diversification of income generating activities. This will go along way in shedding off some of the pressure on the land. These activities could be farm or non-farm based. For example, commercial composting may be encouraged as an avenue to supply some of the farmers with alternative safe and cheap farm inputs. Other activities may include apiculture, renewable energy generation etc.

4. Re-planned farming system. This may involve a change in the crops being grown, such that high income generating crops may be incorporated in one round of farming so as to reduce the necessity of having to go for second round within the same season.