Surface-to-food pesticide transfer as a function of moisture and fat content

Abstract

b National Council on the AgingTransfer of pesticides from household surfaces to foods may result in excess dietary exposure in children (i.e., beyond that inherent in foods due to agricultural application). In this study, transfer was evaluated as a function of the moisture and fat content of various foods. Surfaces chosen for investigation were those commonly found in homes and included Formica s , ceramic tile, plastic, carpet, and upholstery fabric. Each surface type was sprayed with an aqueous emulsion of organophosphates, fipronil, and synthetic pyrethroids. In the first phase of the study, multiple foods (apples, watermelon, wheat crackers, graham crackers, white bread, flour tortillas, bologna, fat-free bologna, sugar cookies, ham, Fruit Roll-ups s , pancakes, and processed American cheese) were categorized with respect to moisture and fat content. All were evaluated for potential removal of applied pesticides from a Formica surface. In the second phase of the study, representative foods from each classification were investigated for their potential for pesticide transfer with an additional four surfaces: ceramic tile, plastic, upholstery, and carpet. Moisture content, not fat, was found to be a determining factor in most transfers. For nearly all surfaces, more efficient transfer occurred with increased hardness (Formica and ceramic tile). Comparatively, the polymer composition of the plastic delivered overall lower transfer efficiencies, presumably due to an attraction between it and the organic pesticides of interest.

Influences on transfer of selected synthetic pyrethroids from treated Formica to foods

“…Formica was chosen because it provided a flat, hard surface. It would likely produce the maximum TEs that might be observed with similar household hard surfaces, as shown in earlier work (Rohrer et al, 2003;Bernard et al, 2008: Vonderheide et al, 2009a.…”

“…The four foods chosen for these experiments represent the characteristics that have been shown to impact transfer F fat and moisture contents (Vonderheide et al, 2009a). High fat and high moisture foods are efficient at transferring pesticides from contact with treated hard surfaces.…”

“…Four foods were investigated: thinly sliced Oscar Mayer bologna, Wonder sandwich style white bread, round sugar cookies (store brand), and raw, red delicious apples. Foods were selected based on moisture and fat contents, which were representative of those used in earlier work (Vonderheide et al, 2009a). All were exposed to a 20 Â 20 or 400 cm 2 coupon of Formica laminate (purchased at a local hardware store) treated in a spray chamber with an aqueous emulsion containing five synthetic hydrophobic pyrethroids (bifenthrin, permethrin, cyfluthrin, cypermethrin, and deltamethrin) (Bernard et al, 2008).…”

“…However, the factor must take into consideration the impact of the activity (Hubal et al, 2005), that is the multiplication of the transfer that is influenced by the activity. Earlier studies, conducted in the laboratory, determined TEs between certain food and surface combinations (Rohrer et al, 2003;Vonderheide et al, 2009a). The impact of activities, such as surface contacts of a single food item or contacts with food items in multiple locations, on the transfer of contaminants is largely unknown or has been estimated (Akland et al, 2000;Hu et al, 2004).…”

Residential insecticide usage in northern California homes with young children

“…Kitchens and bathrooms were the most common indoor environments treated with spray, followed by bedrooms, family rooms, and dining rooms. Spray applications in the kitchen may deposit on plates, cookware, or surfaces such as counters that may later come in contact with food, potentially increasing exposure (Vonderheide et al, 2009). Spray applications in bedrooms and family rooms where people spend a large amount of time may result in increased inhalation and dermal exposure.…”