A study of hazards associated with playgrounds.

Introduction

Historically, playgrounds have provided children with an outlet for their boundless energy. Children need a physical environment where they can develop motor skills as well as participate in social interactions with their peers. For over a decade, there have been attempts to set standards for playground safety; however, despite all efforts there are no federal standards or regulations governing playground facilities, and only a few states have standards or regulations governing playground facilities. Playgrounds account for almost 200,000 injuries treated in emergency rooms annually (1). Climbing equipment has been implicated in nearly one-quarter of the emergency room visits (2). The U.S. Consumer Product Safety Commission ranked playground equipment as the fifth most hazardous consumer product (3). In a 1988 report, the National Electronic Injury Surveillance System (NEISS) estimated that there were 119,600 injuries associated with playground equipment designed for public use (4). Abrasions, contusions, and lacerations account for the majority of reported playground injuries.

According to the 1988 NEISS report, falling is the most common mechanism of injury on playgrounds, accounting for 58% of all incidents. Climbing equipment was implicated in 23% of the cases, swings 16%, slides 13%, and other climbing equipment 6% of the playground injuries associated with falling (4). Head injuries are of utmost concern, because they are most likely to result in the death of a child. A fall from as little as three to five inches onto a concrete or asphalt surface could result in an impact force of 210 g (G-force: unit of force equal to the gravity exerted on a body at rest). This is above the 200 g impact force necessary to cause a fatal injury (Table 1).

The severity of head injuries due to falls is strongly correlated with the type of material used to surface the playground. Hard playground surfaces pose a substantial risk to child safety. A study published by the Epidemiology Hazard Analysis (EPHA) in 1990 suggests that nine out of 10 serious injuries may be attributed to falls onto playground surfaces (5).

Traditionally, material s such as concrete, asphalt, dirt, and grass have been used as surfacing material s for playgrounds. These types of surfacing materials are used because they require minimal maintenance. However, despite their frequent use, these materials are considered unsuitable for surfacing playgrounds (6). One study suggests that such hard surfaces contribute significantly to the number of injuries incurred by children each year (7). Sand, wood chips, and ground tire matting are common alternative surfacing materials. These materials provide an impact-absorbant surface that may prevent or minimize fall fatalities when maintained at the recommended depth. The U.S. Consumer Product Safety Commission has tested surfacing materials. The test results and suggestions as to usage and situational applicability can be found in the Handbook for Public Playground Safety (6).

The results reported herein represent a 1994 survey of 19 playgrounds in a northern suburb of Detroit, Michigan. The public playgrounds were surveyed in order to identify and quantify safety hazards.

Research Procedure

A stratified random sample of public playgrounds was drawn from the Detroit Northern Suburb Map of public parks and playgrounds. Fifty-five playgrounds were stratified into seven distinct groups. Each group was composed of all playgrounds located in a particular neighborhood or school district. The seven groups were chosen in order to include equal representation of playgrounds from affluent as well as economically disadvantaged neighborhoods. Three playgrounds from each of the seven groups were selected by simple random sampling. From the initial 21 selected playgrounds, two were eliminated from the study due to a lack of playground equipment at those locations.

Table 1. Drop Height at Which a Fatal Injury Can Occur from a Fall,
by Surface and Depth of Surface (8).

Surface            Surface Depth(a)     Drop Height     G-Force(b)

Concrete               5 in.               1 in.           210
Asphalt                4 in.               2 in.           210
Foam Matting           1.25 in.            4 ft.           200
Rubber Matting         1.75 in.            5 ft.           225
Gravel                 9 in.              12 ft.           190
Sand (coarse)          9 in.               6 ft.           235
Sand (fine)            9 in.               6 ft.           215
Wood Chips             9 in.              11 ft.           220
Wood Mulch             9 in.              12 ft.           135

a At ambient temperature, not compressed.

b The threshold for serious injury is a force of 50 g; the threshold
for fatal-injury is 200 g.

The study sample consisted of 19 public playgrounds, which were evaluated over a 14-week period during the summer of 1994. Each playground was observed a minimum of three times during the 14 weeks, and all modifications made between visits were noted. The actual surveys were completed by a single observer using a structured instrument developed in accordance with the U.S. Consumer Product Safety Commission guidelines (6), with expert opinions within the field of playground safety, and with studies done on playground injuries and fatalities. (This instrument is available from the authors upon written request.)

The survey instrument consisted of 78 specific safety hazards which were divided into categories based upon known hazards that NEISS has documented to cause injury (4). The categories included the playground's location, general maintenance of equipment, spacing and location of equipment, ground surface, slides, climbing equipment, swings, seesaws, and other specific equipment known to cause injuries. These categories were then subdivided into specific hazards. Each piece of playground equipment was evaluated for possible safety hazards. All hazards associated with each piece of equipment were noted. The playground surface material was checked as to type, proper depth, and distance between the surface material and equipment. The location of the playground was assessed for traffic hazards due to adjacent streets, to lack of protective fencing, and to ease of access by children on bicycles. The playground site was also assessed for projectile hazards posed by adjacent sports activities such as baseball fields and for warning signs alerting motorists of the playground's location. Comments were made at the end of each observation as to the general overall condition of the playground. Each hazard was evaluated as to the type of injury that was likely to occur as a result of such a hazard being present. Each hazardous condition was given a hazard rank as shown in Table 2. Hazard ranking is a way in which the data for the various types of hazards identified can be weighted to reflect its potential to cause injury.

Results

During the course of the 14-week study, a total of 474 separate hazards were identified at the 19 evaluated playgrounds. Of the 474 hazards cited, the location of the playground itself accounted for 14% of hazards, general equipment maintenance 22%, ground surface 18%, spacing and location of equipment 9%, slides 15%, climbing equipment 10%, swings 9%, and other hazards 3%. When hazard ranking (see Table 3) is applied to the observed hazard frequency data, the data become more useful measures of playground hazards. When the observed hazard frequency data are multiplied by the hazard ranking factors presented in Table 2, the location of the playground accounts for 12% of hazards, general equipment maintenance 8%, ground surface 34%, spacing and location of equipment 9%, slides 14%, climbing 19%,swings 5%, and other hazards 3%. Table 3 illustrates statistically the shifts in relative risk after hazard ranking is applied to the observed hazard frequency data. The shifts in relative risk after hazard ranking are also illustrated graphically in Figure 1.

Table 2. Hazard Ranking Based on Injury Severity-Adapted from Bond
and Peck, 1993 (9).

Injury                              Rank

Minor bruises and lacerations(a)      1

Moderate bruises and
lacerations(b)                        2

Severe lacerations and
fractures(c)                          3

Strangulation and head
entrapment                            4

Head injuries                         5

a A minor injury is defined as one in which the child is hurt but
continues to play.

b A moderate injury is defined as one in which the child is hurt and
leaves the playground.

c A severe injury is defined as one in which the child needs
professional medical assistance.

After hazard ranking is applied to the hazard frequency data, climbing equipment accounts for the greatest proportion of the moderate and severe hazards observed, with slides not far behind. Swings show a decrease in relative risk of injury compared to other potential hazards because they account for the majority of the minor bruises and minor lacerations. Safety guards on swings and guard rails on slides and climbing equipment were observed to be inadequate to prevent injuries from occurring on several playgrounds surveyed. The hazards associated with safety guards and guard rails might otherwise have gone unnoticed, but they are reflected in the data when the hazard ranking was applied.

Of the 19 playgrounds surveyed, 91% had hazards identified that were associated with ground surfacing material. Some or all of the accessible playground equipment with no impact-absorbing ground cover material accounted for 58% of the playgrounds. Of those playgrounds that did use impact-absorbing ground cover material around play equipment, 83% were of inadequate depth as specified in Table 1. In addition, the ground cover material on many playgrounds was littered with broken glass, small pieces of metal, and other debris.

Table 3. Percent Distribution of 474 Hazards that Were Observed on
19 Detroit, Michigan, Playgrounds.

Hazard                  Before Hazard Ranking   After Hazard Ranking

Playground Location              14%                     12%
Equipment Maintenance            22%                      8%
Surface Material                 18%                     34%
Spacing of Equipment              9%                      9%
Slides                           15%                     14%
Climbing Equipment               10%                     19%
Swings                            9%                      5%
Other                             3%                      3%

Equipment maintenance was another major problem; 61% of all equipment was poorly maintained. Poor maintenance resulted in a variety of potential hazards. For example, the majority of all wood equipment was well worn and splintering. Of the 19 playgrounds surveyed, 84% had equipment with exposed bolts, screws, and nails. Paint chipping off of playground equipment was observed at nearly all of the playgrounds surveyed. Improper or inadequate equipment maintenance accounted for 67% of all hazards known to cause minor bruises and lacerations.

Access to playgrounds was also found to be a potential hazard. In many cases, the playground was located in such a way that children would be at risk from hazards associated with vehicular traffic. Of the 19 playgrounds surveyed, eight were unfenced and bordered by two or more streets, and seven unfenced playgrounds bordered parking lots. During the natural course of play, children were observed running out into streets. An additional seven playgrounds bordered some type of playing field, thus increasing the risk of injury due to flying objects, such as balls. Only four playgrounds surveyed were completely fenced in and away from streets and playing fields. Only one of these had a bike path for safe access to the playground area. It was also noted that none of the playgrounds were accessible to the disabled.

Factors relating to equipment use were also employed to assess the risk for injury. Children were observed using playground equipment with no adult supervision on seven of the 19 playgrounds surveyed. At five locations, guardians were observed placing small children on playground equipment that was obviously beyond the child's developmental level. Crowding on equipment was observed at two locations. This also increases the risk for injury.

Conclusions

The results of this study are consistent with the NEISS report and studies done in other urban areas. The NEISS report cites falling as the most common cause of injury on playgrounds (4). In a survey of 47 public playgrounds in Boston, Massachusetts, climbing equipment accounted for 34% of hazards, slides 30%, and swings 22% (9), after a similar hazard ranking was applied to the observed hazard frequency data. The Boston study considered equipment only; it did not evaluate the playground location. In addition, the Boston study did not address hazards associated with ground surface. In a survey of 57 school playgrounds in Philadelphia, Pennsylvania, 99% of the climbing equipment and slides were considered unsafe due to the lack of proper ground surfacing material (8). Despite the differences in methodology, the conclusions reported herein are strikingly similar to those reported in the Boston and Philadelphia studies.

This study demonstrates that children who use playgrounds in the northern suburbs of Detroit, Michigan, are at risk to a variety of hazards. These hazards are likely to be found on playgrounds across the United States. Many of the hazards associated with playgrounds could be minimized if reasonable standards were mandated and enforced.

Recommendations

This study demonstrates the need for a national comprehensive playground safety program that can provide recommendations to policymakers in order to set standards and regulations for playground safety. The Handbook for Public Playground Safety could be used as a starting point for federal, state, and local safety regulations governing playgrounds.

Once safety regulations for playgrounds are mandated, new playgrounds should be built according to recommended safety standards, and old playgrounds should be renovated to meet safety standards. Such recommendations are as follows:

1. Playgrounds must be accessible to all children, including the disabled.

2. There should be a well-defined playground area for preschool children with equipment designed for their safety and developmental needs.

3. Playground equipment should be checked on a routine basis for safety hazards. Wooden equipment should be routinely sanded and exposed nails hammered into the wood. Swings should be checked for pinch points due to S-hooks; climbing equipment should not have exposed nuts and bolts.

4. Playground equipment that does not meet safety standards should be repaired or removed.

5. Ground surfaces should be covered with materials that will absorb the impact of falls. Ground surfacing material should not be allowed to pack down, and the depth of material should be kept at a safe level.

References

1. Centers for Disease Control (1988), "Playground related injuries in preschool-aged children-United States, 1983-1987," MMWR, 37:629-632.

2. Boyce, W.T., S. Sobolewski, L.W. Sprunger, and C. Schaefer (Sept. 1984), "Playground equipment injuries in a large, urban school district," Am J of Pub Health.

3. Reichelderfer, T.E., A. Overbach, and J. Greensher (1979), "Unsafe Playgrounds," Pediatrics.

4. National Injury Information Clearinghouse (July 1993), NEISS Summary Report, U.S. CPSC Washington, D.C.

5. Tinsworth, D.K., and J.T. Kramer (April 1990), Playground Equipment Related Injuries and Deaths, EPHA, Washington, D.C.

6. U.S. Consumer Product Safety Commission (1990), Handbook for Public Playground Safety.

7. Sosin, D.M., P. Keller, J.J. Sacks, M.J. Kresnow, and P.C. Van Dyck (May 1993), "Surface-specific Fall Injury Rates on Utah School Playgrounds," Am J of Pub Health.

8. Ramsey, L.F., and J.D. Preston (March 1990), Impact Attenuation Performance of Playground Surface Material, U.S. CPSC, Washington, D.C.

9. Bond, M.T., and M.G. Peck (March 1990), "The Risk of Childhood Injury on Boston's Playground Equipment and Surfaces," Am J of Pub Health.

10. Ridenour, M.V.F. (1987), "Elementary School Playgrounds: Safe play areas for inherent dangers," Precept Motor Skills, 64:447-451.

Sandra K. Allen, A.B., M.B.A., Ph.D., Dept. of Health & Safety, Indiana State University, Terre Haute, IN 47809