PURPOSE OF THE STUDY.
The goal of this study was to assess potential routes of transfer of peanut protein into the home environment and to assess the effect that cleaning methods have on environmental peanut protein levels.
Forty-five families were recruited from pediatric allergy clinics.
To quantify ambient household peanut levels, dust samples from all household members’ beds and the infant’s play area were obtained by vacuuming. Wipe samples were obtained from the infant’s and parents’ eating areas, as well as other surfaces in the home. Peanut protein in the samples was measured by using enzyme-linked immunosorbent assay and converted to micrograms of peanut protein per gram of dust. Peanut protein was also measured from hand wipe and saliva samples before and 3 hours after subjects ate peanut products. To measure airborne peanut protein, air samplers were placed 1 cm and 1 m above open containers of peanut products for 22 hours and over a pan of simmering peanut-flavored sauce for 10 hours. In addition, air samples were obtained at and around researchers during and after they ate peanut products. Various table surfaces were spiked with peanut and then cleaned with water or detergent and sampled for residual peanut protein.
Dust from the infant’s play area had the highest peanut protein level, followed by the parents’ bed and siblings’ beds. Correlation between concentrations in various areas of the home was high. Levels in wipe samples were lower than in dust, and the median was below the lower limit of quantification for the assay. Levels of peanut protein on a sofa cover and a pillow case increased after peanut consumption. After the items were washed twice, the level of peanut protein on the items was dramatically decreased. Peanut protein levels on hands and in saliva remained elevated 3 hours after consumption. Except for when dry roasted peanuts were being shelled, median airborne peanut protein levels were below the lower limit of quantification. After wiping the spiked table surfaces with water, there was only a small reduction in the amount of peanut protein on the surface. After vigorous detergent cleaning, there was a reduction but protein was still measurable on the wood and laminate surfaces (but not on the granite surfaces).
Peanut protein can easily spread throughout a home but probably not by aerosolization. It may be resistant to usual cleaning methods.
Our mothers were right, to a certain extent. We should still wash our hands and clean up after ourselves after eating. After eating peanut products, these steps will reduce but not eliminate residual peanut in the environment. This study shows that peanut can then be transferred throughout the home. The amount found would likely not trigger symptoms in an allergic patient. However, the following article in the same issue of the Journal of Allergy and Clinical Immunology by the same group indicates that environmental peanut protein is biologically active and therefore has the potential to contribute to sensitization.
- Copyright © 2014 by the American Academy of Pediatrics