Getting the Dirt on Play


“Let your child be a child. Dirt is good. If your child isn’t coming in dirty every day, they’re not doing their job. They’re not building their immunological army.”  Dr Mary Ruebush, immunologist and author of Why Dirt is Good: 5 Ways to Make Germs Your Friends

This post may make you feel really yucky but bear with me, it’s important.

Over the past few decades there has been a growing body of research that points to the role of the bacteria in our gut to our health. Most of us carry around about five pounds “of not us” stuff, something like 100 trillion little beasties, mostly in the lower G. I. tract. Without them, we could not metabolize what we eat.

We are beginning to understand that establishing this diverse community of mostly bacteria and keeping it balanced is essential to health. For one thing, when they are functioning optimally, they crowd out bad bacteria that can trigger disease. The first major breakthrough in this area was in 1982 when it was discovered that ulcers are not caused by stress or diet but by the bacteria Helicobacter pylori.

Poor intestinal health has subsequently been implicated in obesity, autoimmune diseases such as MS and lupus, Parkinson’s, acne, cancer, asthma, ADHD, and diabetes. The most recent research is finding connections with behavior and moods as well as a strong implication with autism.

This is serious stuff. One of the reactions to this flood of new research is to review the use of antibiotics, painkillers, and other medications, which have been shown to damage the microbiome. Currently, there are also major studies looking at the impact of genetically modified foods, as tests connected on mice seem to indicate a problem with them and gut health as well.

The bacteria in our guts are derived from many sources. Babies pick up their first load during birth and the type of delivery makes a big difference. They also begin to get them from physical contact with adults.

It appears that some of the most important denizens of our gut come from dirt. Mycobacterium vaccae is found in soil and stimulates serotonin production, which makes you relaxed and happier. Researchers found that “Exposure to friendly soil bacteria could improve mood by boosting the immune system just as effectively as antidepressant drugs.”

In this article, Toddler temperament could be influenced by different types of gut bacteria, it is reported that researchers “found that children with the most genetically diverse types of gut bacteria more frequently exhibited behaviors related with positive mood, curiosity, sociability, and impulsivity.”

In 2010 researchers established “that mice that were fed live M. vaccae navigated the maze twice as fast and with less demonstrated anxiety behaviors as control mice.” So dirt not only makes us happy, it also makes us smarter.

Of course, microbes in large doses in some dirt can be bad for us, but in small amounts, our immune systems are wonderfully designed to select the good from the bad. When the exposure is moderate, the more bacteria, viruses, and parasites our immune system is exposed to the better chance we have of warding off diseases. Research has shown that children who grow up on farms have lower allergy and asthma rates, a phenomenon attributed to their regular exposure to microorganisms present in farm soil. Another study found that infants in homes with a greater variety of bacteria were less likely to develop environmental allergies and wheezing at age 3.


What’s Gut Health Have to do With Play?

Perhaps we should not be surprised that playing in the dirt makes us happy or that gardening elevates our mood, but few of us would go on to assume that these activities are absolutely essential to our health. It is even more unlikely that we would go even further and say that the earlier such playing with dirt occurs the better.

Of course, allowing children, especially infants, to be exposed to dirt is primarily at the discretion of parents, but as the evidence grows that the long-term health of each individual depends on the dirt that they play in, we may see a time when the essential and beneficial microbes are isolated and children are routinely inoculated at birth.

The fact that M. vaccae continues to elevate our mood throughout our lifespan suggests that our bodies continue to benefit from re-exposure to dirt. When we lived as hunter-gatherers or farmed by hand, such long-term contact with soil was no problem. In today’s highly urbanized world getting dirty is becoming increasingly problematic. As the correlation between microbes and disease gets increasingly well understood, some researcher in the not-to-distant future will do the math and determine that the health care cost to society’s fixation on hygiene is so large that it may well become the number one cause of preventable disease. The good news is that this will mean that community gardens, which are already very popular, will become ubiquitous. The other impact will be that dirt pits will become a standard feature of early childhood programs.

For more information and a great resource, list visit the Stay At Home Educator Blog.

Here are various posts that expand this idea:

This article first appeared in Playground Professionals November 23, 2015

Just Stop It!

bad ADA design

“Hey! Let’s go to Long Ramp Playground,” said no kid ever.

As followers of my posts will know, one of my self-appointed missions is to push for better playgrounds with more play value. Nowhere is the problem of bad playspace design more rampant than in the area of “accessible” playgrounds. To look at this in detail, let’s look at a particularly egregious new playground in New Jersey.

The basic layout of the play structure is one long ramp with interactive events every 12 feet. This results in a path of travel exceeding 40 feet in total length. As you can see from the photo, there are no access points along the majority of this run. Parents are either blocked from assisting their child with special needs or required to follow them throughout the child’s play, turning them into helicoptering parents. Exactly the thing we don’t want if our goal is to maximize social interaction between children of differing abilities.

The culmination of this epic journey up the ramp is a small, plastic slide with a climber and fire pole. Since this is the only portion of the structure with active play elements, modest though they may be, it will become very crowded by physically active kids making access to the slide for children with limited mobility problematic on busy days.

So let’s walk through the play experience for a child who uses a wheelchair. The child goes up each incline to a station that provides an “interactive” event. In this case, “interactive” is a misnomer because these events are designed to provide a single child with an equipment-to-equipment experience and only marginally supports child-to-child interaction. The problem with these supposedly interactive events is that they are appealing primarily to children who are not yet developmentally ready for social and cooperative play. Of course there is a percentage of the population with special needs for whom this is appropriate, but it is a small fraction, and the goal for these children is to provide play opportunities that will foster engagement with other children—a goal at which this design fails miserably.

Continuing up the ramps to the apex, what can we expect will happen for the child using a wheelchair? There are two possibilities, assuming the child can actually get through the crowd and near enough to the slide to use it: If the child has transfer skills or an assistant, he or she can exit the chair and slide down. Now the chair is at the top and the child is at the bottom. The chair has to be brought around an 80-foot trail back down to the slide exit while our player waits at the bottom of the slide. What a humiliating and predictable disaster for the child! In order to reduce the trauma, the parent will have to enlist another adult to tend to the child while she rushes around to reunite the child with the chair. The other scenario is that the child does not have transfer skills, and so he or she must turn around and exit via the long ramp.

The layout of this play structure is spectacularly poor. The long, narrow design requires much more expensive poured-in-place surfacing than if the design was rectilinear. This layout also prevents interaction of children across the structure, as would be the case with a better layout. So here we have an incredibly expensive play structure plus the surfacing, just because the design goal has to provide an elevated slide as the preferred play experience. If the design goal had been thought through, it would have been predictable that this design was going to be dysfunctional and traumatic for the small population for which it was intended.


By changing the design goal, this project need not have been such a failure. There are many wonderful options that can engage children of all ability in cooperative play. Take for example the BigToys Turn-Across. The installation shown here would have been even better if it was over poured-in-place rubber instead of engineered wood fiber. Not only is that a more accessible surfacing, but it also would eliminate the need to constantly maintain the EWF that will be displaced by the children going back and forth.

This unique design requires that children play collaboratively. Here, children using chairs can be leaders of the play, and if they have transfer skills they can join with other kids riding the gondola. Rather than setting the play experience as elevated sliding would, no safety surfacing is required, saving tens of thousands of dollars. With these savings, several other products that are on the market with similar ground-based functionality could be purchased, or much higher-quality, musical devices could be provided that will be far more appealing than the roto-cast elements seen on the ramp structure.


Thus, with the same—or less funding—the playspace could have several really inclusive and exciting zones where all children can play together.

How did we get into the mess?

Good question. In my experience, the whole ADA-standards setting process was high-jacked by wheelchair-access advocates. The narrow focus on the path of travel was, to my thinking, a misinterpretation of the Americans with Disabilities Act—which was aided and abetted by the consultants provided by the Access Board, who guided the rule-making process. In recent interviews, the Access Board representatives are unapologetic about the process, having been focusing almost exclusively on mobility access to the exclusion of the vast majority of other sorts of needs.

For example, children with autism can only play independently if the playspace is fenced. Acoustic guides benefit children with vision impairments. Children with sensory issues need safe places where they can retreat when they become overloaded. The list is almost endless of the ways in which children of all abilities can be supported in playing together. Go back and reread the playground ADA standards and see if you find any reference to design concepts that will foster inclusiveness.

While the Access Board and their consultants bear the bulk of the responsibility for the failure to provide for inclusive design, the playground industry continues to perpetuate this fraud in playground after playground. They are eager to take the dollars from well-meaning communities to sell designs that they know are just plain wrong. Manufacturers can and should do a better job of developing inclusive options. They also bear a responsibility to train their regional sales personnel in what good design is and how to communicate those ideas to the public.

inclusive play

What to do?

There are great examples of inclusive design. My current favorite is Magical Bridge Playground in Palo Alto, California. The team at Magical Bridge, frustrated by the lack of inclusive apparatus from U.S. suppliers, went primarily to equipment suppliers in Europe who have a much better sense of design and sensitivity to the issues of inclusion. To learn more the playground, check out the attached brochure. For questions, contact Olenka at

If you are interested in moving beyond ADA to provide full play for all:

To the public I say, “Don’t buy into the ADA ramps-only solution. Do your homework—there are some really great inclusive playspaces from which you can get good ideas.”

To the manufacturers, I call for innovation and better understanding of the whole range of abilities and the opportunities they present.

To the salespeople, I demand that you do some soul-searching and not take the easy way out; educate your customers about inclusive design. If you find that you don’t have good options, then lobby your supplier for better options.

To the parks and recreation professionals who are supposed to know better, I say, “Just stop it. Just stop allowing these overly ramped playgrounds that don’t work in your system.”

This post first appeared in Playground Professionals 11-10-15