Pediatric insecticide chalk exposures reported to Texas poison centers

Abstract

The pesticide Miraculous Insecticide Chalk^TM is illegal in the United States but can be obtained through a variety of sources. Because it is a stick similar in appearance to common blackboard chalk, children might play with it and put it in their mouths. All Miraculous Insecticide Chalk exposures involving children 5 years or younger reported to Texas poison centers during 2000–2010 were identified. The distribution by selected demographic and clinical factors was calculated. Of the total 188 exposures, the mean age was 1.5 years (range 6 months–5 years) and 60.6% were male. Ingestions were reported in 97.3% of the exposures, and these were reported to involve at most one stick of the chalk. The lowest exposure rates per 100,000 population of 5 years or younger were reported in the Public Health Regions in northern and eastern Texas (0.00–2.30) and the highest rates in the Public Health Regions in southern and western Texas (19.08–39.50). Of the 187 exposures not involving other substances, 96.8% were known or expected to result in at most minor effects, and 71.1% were managed on site (at residence).

Introduction

Miraculous Insecticide Chalk^TM, manufactured in China, is reported to contain the synthetic pyrethroid compound deltamethrin and also may contain cypermethrin. ^{1 –5} It is used to draw lines as boundaries in order to control insects such as ants and roaches. ^{1 –5} The insecticide chalk is not registered with the United States Environmental Protection Agency (EPA) and is illegal in the United States. ^1,2,5 However, the insecticide chalk is imported illegally from China and is reportedly sold through flea markets and Chinese import stores. ^2,5

The product’s label may make claims that the chalk is “harmless to human beings and animals” and “safe to use.” ³ However, because it is a stick similar in appearance to common blackboard chalk, children might play with it and put it in their mouths. ² The insecticide chalk is reported to be mildly toxic, but ingestion may result in such symptoms as vomiting, abdominal pain, convulsions, tremors, loss of consciousness, and serious allergic reactions. ^2,4,5 Ingesting one piece of insecticide chalk or less by a child should require no medical therapy. No antidote is known. ^4,5

Review of the literature for information on this product identified only one case report where a 1.5-year-old female ingested half a piece of chalk. The girl experienced vomiting, cough, fever, drowsiness, and irritability. There was a delay in seeking treatment because of a perception that the product had low toxicity. ³

Poison centers in the United States are contacted to assist in the management of potentially adverse exposures to a wide variety of substances, including pesticides. ⁶ The objective of this investigation was to describe Miraculous Insecticide Chalk exposures by young children reported to a statewide poison center system.

Methods

This retrospective study utilized data collected by the Texas Poison Center Network (TPCN), a system of 6 poison centers that service the entire state, a population of over 20 million. All the poison centers in the system use a single database to collect demographic and clinical information on all calls in a consistent manner.

Cases were all Miraculous Insecticide Chalk exposures involving patients of age 5 years or younger reported to the TPCN during 2000–2010. The distribution of the cases was determined for year, month, patient age and gender, route of exposure, quantity of product, circumstance of (reason for) the exposure, exposure site, geographic location, and whether other substances were involved in the exposure. Analysis of the quantity of the product was limited to those exposures that occurred through ingestion of the chalk. The geographic location was examined using the 254 Texas counties and 11 Public Health Regions (PHRs) into which Texas is divided. For the PHR analysis, the exposure rate per 100,000 children aged 5 years or younger was calculated using data from the 2000 Census as the denominator.

For those cases not involving other substances, the distribution was determined for medical outcome, management site, and reported adverse clinical effects and treatments. Those cases involving other substances were excluded from these latter analyses because other substances might have affected the management or outcome of the patients.

The medical outcome is assigned by the poison center staff managing the exposure and is based on the observed or anticipated symptoms. Medical outcome is classified according to the following criteria: no effect (no symptoms due to exposure), minor effect (some minimally troublesome symptoms), moderate effect (more pronounced, prolonged symptoms), major effect (symptoms that are life threatening or cause significant disability or disfigurement), and death. A portion of exposures are not followed to a final medical outcome because of resource constraints or the inability to find subsequent information on the patient. In these instances, the poison center staff recorded the expected outcome of the exposure. These expected outcomes are grouped into the following categories: not followed but judged as nontoxic exposure (symptoms not expected), not followed but minimal symptoms possible (no more than minor symptoms possible), and unable to follow but judged as a potentially toxic exposure. Another medical outcome category is “unrelated effect” where the exposure was probably not responsible for the symptoms.

Race/ethnicity was not included in the TPCN database and thereby could not be directly evaluated.

No attempt was made to perform the analyses of statistical significance. The Texas Department of State Health Services institutional review board exempts this study from ethical review.

Results

Of the 210 insecticide chalk exposures reported to Texas poison centers during 2000–2010, 188 (89.5%) involved patients of age 5 years or younger. During the same time period, there were 1,016,259 total reported exposures among the patients aged 5 years or younger, of which 45,087 involved some form of pesticide.

The annual number of insecticide chalk exposures among young children ranged from 10–25, with no clear annual trend. There was a seasonal pattern with 49 (26.1%) of the exposures occurring during June–July and 84 (44.7%) during May–August.

The geographic location was known for 185 of the cases. These cases were reported from 37 of the 254 Texas counties. Two of the counties (Bexar and Hidalgo) accounted for 67 (36.2%) of the cases and 5 of the counties (Bexar, Hidalgo, Cameron, El Paso, and Nueces) accounted for 114 (61.6%) of the cases. Figure 1 shows the insecticide chalk rate of exposure among young children by PHR. The rate was highest in southern and western Texas and lowest in northern and eastern Texas.

Figure 1.

Insecticide chalk exposure rate among children aged 0–5 years reported to the Texas Poison Center Network during 2000–2010 by Public Health Region.

The mean age of the patients was 1.5 years (range 6 months–5 years). The age distribution was 23 (12.2%) of less than 1 year, 72 (38.3%) of 1 year, 73 (38.8%) of 2 years, 12 (6.4%) of 3 years, 5 (2.7%) of 4 years, 1 (0.5%) of 5 years, and 2 (1.1%) of unknown exact age. Of the cases, 114 (60.6%) were male and 74 (39.4%) were female.

The exposure occurred via ingestion in 183 (97.3%) cases, dermal contact in 15 (8.0%) cases, and inhalation in 1 (0.5%) case. Some of the exposures occurred by multiple routes. In nine the exposure occurred by ingestion and dermal contact and in one by ingestion, dermal contact, and inhalation. Of the 183 ingestions, 136 (74.3%) involved only a “taste” of the chalk, 26 (14.2%) a portion of 1 stick, 10 (5.5%) 1 entire stick, and 11 (6.0%) an unknown amount.

The exposures occurred at the patient’s own residence in 179 (95.2%) of the cases and at another residence in 9 (4.8%) of the cases. All of the exposures were unintentional. Only one of the exposures was reported to have involved an additional substance (rat poison).

Of the 187 cases involving no other substances, 133 (71.1%) were managed on site (at a residence), 48 (25.7%) were already at or en route to a health care facility when the poison center was contacted, 5 (2.7%) were referred to a health care facility by the poison center, and 1 (0.5%) was managed at an unspecified site. The distribution by medical outcome was 53 (28.3%) cases with no effect, 6 (3.2%) with minor effect, 2 (1.1%) with moderate effect, 14 (7.5%) not followed and no clinical effects expected, 108 (57.8%) not followed with minimal clinical effects expected, 1 (0.5%) unable to follow and judge the potential toxin, and in 3 (1.6%) cases the clinical effects were considered unrelated to the exposure. No major effects or deaths were reported.

The most frequently reported specific clinical effects were vomiting (12, 6.4%) and nausea (4, 2.1%). Clinical effects reported twice were dermal irritation or pain, diarrhea, and coughing or choking. Clinical effects reported once were oral irritation, diaphoresis, and drowsiness or lethargy.

Treatments reported more than once were dilution or wash (158, 84.5%), food or snack (10, 5.3%), activated charcoal (5, 2.7%), other unspecified emetic (5, 2.7%), intravenous fluids (3, 1.6%), and cathartic (2, 1.1%). Treatments reported once were antiemetics and antihistamines.

Discussion

This investigation described Miraculous Insecticide Chalk exposures reported to Texas poison centers during a recent 11-year period. Such information is important because the product is illegal in the United States, and yet exposures, particularly among young children, continue to occur. However, there is little information in the published literature on the pattern and outcome of such exposures.

The study is subject to several limitations. Reporting of potentially adverse insecticide chalk exposures to Texas poison centers is voluntary. As a result, it is not likely that all such exposures are reported to the Texas poison centers. Moreover, those exposures that are reported may not be representative of all such exposures that are occurring in the state.

Another limitation is that the exposures were often based on reports by the patient’s family or others caring for the children. A portion of the exposures may not have actually occurred. In addition, the quantity involved in the exposure was usually reported in vague terms such as “a taste” or “a part of a stick” and was not based on clinical measures.

A total of 188 insecticide chalk exposures among children aged 5 years and younger were reported to Texas poison centers during 2000–2010. This represents a fraction of the total exposures, and all pesticide exposures, among this age group. This might suggest that insecticide chalk exposures among young children are relatively uncommon in Texas, particularly when compared with other types of exposures and even those including other pesticides. However, it may be that the public may consider the product to be nontoxic, particularly since its labeling may contain such phrases as “harmless to human beings and animals” and “safe to use.” ³ Because of this labeling and the fact that the product is illegal in the United States, people may be unlikely to seek health care assistance when a potentially adverse exposure to the product has occurred.

The insecticide chalk exposures tended to be concentrated in certain parts of Texas. Three-fifths of the exposures were reported from only five counties, all of which were in the southern and western part of the state. Moreover, the exposure rates were lowest in the northern and eastern parts of the state and highest in the southern and western parts of the state. This geographic pattern was roughly similar to the distribution of the Hispanic population in Texas. The four PHRs with the highest insecticide chalk exposure rates also have the highest proportion of the population that is Hispanic. The two PHRs with the lowest insecticide chalk exposure rates have the lowest proportion of the population that is Hispanic. This pattern may suggest that the Hispanic population, particularly close to the border with Mexico, is more likely to use insecticide chalk, or at least use it in such a way that potentially adverse exposures among young children may occur. Although illegal in Mexico, the product is available in that country. ³ The free notes capture area of several of the cases mentioned that the product was purchased in Mexico. Texas poison centers do not collect information on the patient’s race/ethnicity, so this variable could not be directly evaluated in this study. In any event, the observed geographic distribution of insecticide chalk exposures suggests that education and prevention activities can be targeted to those areas with higher risk of these exposures.

Most of the patients were managed at home. Of those patients not already at or en route to a health care facility when the poison center was called, few were referred to a health care facility. Moreover, 181 (96.8%) of the exposures not involving other substances were known or expected to result in at most minor effects. This might be expected because most of the exposures involved only a taste or portion of a stick of insecticide chalk, and none were known to have involved more than one stick. This amount has been considered in the literature to be mildly toxic and not require medical therapy. ^4,5 Twenty-five percent of the patients were already at or en route to health care facility when a poison center was contacted. The relatively mild outcome associated with most of these exposures suggests that they could have been managed successfully at home if the poison center had been contacted prior to treatment sought at a health care facility.

In summary, insecticide chalk exposures involving young children are still a problem in Texas, although they may not occur with great frequency compared to other types of exposures among this age group. The exposures occurred most frequently in the southern and western parts of the state. Ingestions of one stick or less of the insecticide generally result in at most minor effects and could be managed at home.