Household deodorizers and moth repellents are common agents implicated in many childhood poisonings. Their ingredients usually include either paradichlorobenzene or naphthalene compressed into a solid ball or another shape, sometimes with added essential oils and fragrances. Because medically naphthalene is a more important toxin than paradichlorobenzene, with hematologic and nervous system effects, clinicians often seek to discern which product has been ingested. We discovered fortuitously that a mothball swallowed by a retarded adult was radiopaque, and so designed an in vitro experiment to study the radiopacity of a variety of household deodorizers and products. Of 10 products screened for radiopacity by two radiologists, those containing paradichlorobenzene were consistently strongly radiopaque; those containing naphthalene were radiolucent. A third alternative ingredient which is used in some toilet bowl deodorizers, cetrimonium bromide, was also radiopaque. Radiopacity of paradichlorobenzene or cetrimonium bromide-containing products did not dissipate with time. We speculate that the halogen within the chemical structure of these compounds accounts for their radiopacity. We conclude that paradichlorobenzene-containing commercial products can be distinguished clinically from those containing naphthalene by the performance of an abdominal radiograph.

This study investigated the effectiveness of a poison center-initiated mailed intervention on improving the preventive practices of families whose preschool child had recently experienced a poisoning incident. A low-cost, mailed poisoning prevention packet consisting of telephone stickers, a $1 coupon for syrup of ipecac, one slide-style cabinet lock, a nine-step checklist for "poison-proofing" the home, pamphlets, and a cover letter was tested prospectively on a population of parents calling a poison center for advice about possible poisoning exposures involving their preschool children. Parents without ipecac 1 week after the incident were randomized so that half received the mailed intervention. A "blind" follow-up telephone interview was conducted 3 months later. Of the 336 original families enrolled in the study, 301 (90% retention) completed the follow-up interview. Those who had received the intervention were more likely to have a telephone sticker than control families (78% vs 39%; P < .0001) and were more likely to be using at least one slide lock in the home (59% vs 40%; P < .001). However, intervention families were no more likely to have ipecac on hand than control families (57% vs 52%; P = not significant) and did not indicate a higher rate of compliance with suggested changes in other behaviors and practices to prevent poisonings. A poisoning recurrence rate of 3.7% was seen in the total sample during the 3-month period of surveillance; there was no difference between groups in recurrence rate. Even after a poisoning event, parents may not be sufficiently motivated to take poisoning prevention measures on their own. Poison centers can serve as lead agencies in developing effective prevention technologies for reaching out to large numbers of high-risk families. One such technology is a mailed intervention, which can be effective if it removes barriers to compliance with poisoning prevention advice.