As of March 8th, 357 food establishments in Flint, Michigan have received compliance checks and have been verified to be compliant, that is, following the requirements for use of City of Flint water, as directed by the Genesee County Health Department and the Michigan Department of Agriculture and Rural Development (MDARD).
“The companies listed as compliant have demonstrated they are taking precautions to reduce the risk of foodborne illness from water that may be contaminated with lead, as outlined in the Michigan Food Law and Michigan Modified Food Code,” says Kevin Besey, MPA, RS, director of the MDARD Food and Dairy Division.
Lead is a neurotoxin when ingested or inhaled, with potentially serious, harmful health effects.
Flint food businesses not included on the list are not necessarily out of compliance with Michigan food regulations, Besey notes. “Some businesses have not yet received a compliance assessment from food inspectors,” he explains. “Compliance checks are still taking place, and this list is updated as new inspections are done.”
With regards to the criteria for food establishments to be in compliance relative to the Flint water emergency, firms are either found compliant during an MDARD assessment or have passed a water test, Besey says. “A list of Flint food establishments who are in compliance with the current requirements is generated by MDARD and posted on the Flint Water Response website,” he relates.
As of Feb. 22, 2016, reports show that there are three businesses that have been found not in compliance after reassessment, Besey mentions. “Additional data reports that there are 33 more businesses that reported initial noncompliance, however these firms are pending confirmation of a re-inspection to indicate compliance has been achieved after guidance was provided by MDARD,” he says.
According to Besey, letters were sent to all Flint food establishments on Oct. 15, 2015 with recommendation actions, followed by letters to those establishments on Jan. 14, 2016 with legal requirement notices that outlines specific obligations and additional precautions that must be in place for food establishments using City of Flint water. These additional precautions include one or more of the following: having a “not detected” lead water test; flushing the water system for at least five minutes at the start of each day; installing filters on all water sources used in the food business; and/or using bottled water for food preparation and cooking.
“On January 20, 2016 MDARD food inspectors began visiting each licensed establishment to assess compliance with the requirements and collect water samples for testing,” Besey points out. “To date, the majority of food establishments have been found to be in compliance with the regulations and MDARD staff members are working with those who were not in compliance at the initial assessment to come into compliance.”
Moreover, staff continues daily response efforts for licensed food establishments using City of Flint water, Besey continues. “Daily response includes establishment visits, making assessments, sampling, monitoring, re-inspections, and follow-up reporting of sample results.”
Home Gardening Concerns
Not surprisingly, people who farm and garden in Flint are questioning the safety of growing edible plants in soil that has been irrigated with lead contaminated water, according to Phil Tocco, MS, a food safety educator with Michigan State University (MSU) Extension.
“Lead occurs naturally in soils,” says Stephen Boyd, PhD, a MSU environmental chemist. “One estimate of the ‘normal’ background level of total lead in agricultural soils is 10 parts per million (ppm), according to research conducted at the University of Minnesota. Research in Delaware shows a background lead level of 100 ppm.”
Lead dissolved in water used for irrigation is adsorbed by soil particles, and the newly added lead from irrigation water would add to the lead already found in the soils, Dr. Boyd notes.
However, residual lead in urban soils themselves is more of a concern than additional lead added from the irrigation water, Dr. Boyd says, explaining that residual lead is the same as the total lead in the soil, which, in urban settings, could be a combination of natural background lead in soils plus any other lead added, such as from past use of leaded gasoline or other man-made sources like paint chips.
“That’s why soil testing, including testing for environmental contaminants such as lead, is recommended for all new food gardens, as is researching the site’s previous uses,” Dr. Boyd advises.
Earlier this year, Dr. Boyd performed calculations to determine if irrigation of Flint gardens during the 2014 and 2015 growing seasons could have substantially increased the lead levels in the garden soils.
Using the edible flint Demonstration Garden as an example, Dr. Boyd calculated the area (square footage) of the garden, the volume of water used over the growing season (they had a reading from the rented city water meter that is hooked up to a fire hydrant), the concentration of the lead in the water used for irrigating, along with the previous lead level of the soil in the garden.
“I did a simple calculation based on the assumptions that 2,250 gallons of water with a lead concentration in the water of 15 parts per billion were added by irrigation to 2,407 square feet of garden space,” Dr. Boyd explains, adding that “one acre of dry soil 6″ deep weighs approximately 2,000,000 pounds.”
“Based on these assumptions, if the contaminated water added was distributed in the top 6 inches of soil, the background lead level of 10 ppm would have increased by only 0.00256 ppm,” Dr. Boyd relates. “So the total lead concentration in soil in this example went from 10 ppm to 10.0025 ppm. If the lead stayed in the top 1 inch, then the soil lead concentration would go from 10 ppm to 10.015 ppm.”
Thus, in the example where the lead was added to the top 6 inches of soil via irrigation water, the level of lead in those soils would have increased by 0.025 percent if the background lead in the soil was 10 ppm, Dr. Boyd elaborates. “If the soil had a higher background lead level, for example 100 ppm as has been demonstrated in Delaware, the percent increase would be even smaller,” he says. “Either way, the increase in soil lead levels due to irrigation for a year, with water containing 15 ppm of lead, is very small. That would be true if the same irrigation protocol was used for two years.”
“Our edible flint demonstration garden’s most recent soil lead test from Spring 2015 was 93 ppm, and the season’s irrigation water would increase lead in the top 6 inches of soil by just 0.0025 ppm, or just an 0.0025 percent increase in the soil lead level of that garden,” Dr. Boyd reports.
A second MSU soil chemistry professor did these calculations independently and came up with the same answer. “It seems unlikely that lead contaminated irrigation water used for one or two growing seasons had any significant impact on the total lead levels in Flint garden soils,” Dr. Boyd concludes.
Choose Low Risk Vegetables
“In situations where heavy metals like lead and arsenic may be high in the soil, selecting certain vegetables to grow can lower the risk of heavy metal exposure,” Tocco says.
“In some cases, consuming the vegetables grown can be less than healthful,” he notes. “In situations where vegetables are grown in environments high in heavy metals, like lead and arsenic, they can actually concentrate these metals in their tissues. When humans eat these tissues, we further concentrate these chemicals, causing us harm.”
Much research has been done looking at various crops and their relative abilities to accumulate heavy metals while growing, Tocco relates. “Certain vegetables are less likely to accumulate harmful levels of heavy metals than others,” he says.
“In general, heavy metals tend to accumulate in root, leaf, and stem tissue,” Tocco elaborates. “Those vegetables that arise from flowers and are botanically considered fruits are less likely to have harmful levels of heavy metals than leaf, stem, or root crops. In areas where heavy metals are a concern in both soil and water, it is important to keep these things in mind when creating garden plans and selecting seeds.”
Crediting “Lead levels of edibles grown in contaminated residential soils: a field survey,”published in the Science of the Total Environment, Tocco is quick to mention vegetables that are the best choice for situations where heavy metals are a problem, and ones to avoid.
Low risk vegetables include tomatoes, peppers, beans, and zucchini.
“Low risk assumes these vegetables are washed well with a food grade detergent and potable water before consumption,” Tocco emphasizes.
Moderate risk vegetables are cucumbers and melons. High risk vegetables include potatoes, carrots, radishes, onions, collard greens, Swiss chard, lettuce, mint, and cilantro.
“Empower Flint” App
A new mobile device app called “Empower Flint” was recently launched by a team of MSU researchers and WKAR, its affiliate PBS station, in collaboration with Flint residents who test piloted the app.
The app’s features include:
- A “find” operation that allows the user to search for the closest water stations, free water filters and sources of nutritious food, and then pull up a map for directions;
- Push notifications on timely information such as boil water alerts;
- Water safety tips on dealing with the Flint water crisis;
- Health tips to keep families safe and/or deal with lead poisoning issues;
- Nutrition tips to limit the damage of lead exposure;
- Pet safety tips to keep pets safe from lead;
- Community connections for people interested in volunteering and those needing help; and
- A news feed with the latest Flint news.
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