[1] McGill Univ, Ctr Hlth, Dept Paediat, Div Paediat Allergy & Clin Immunol, Montreal, PQ, Canada
[2] Montreal Childrens Hosp, Montreal, PQ H3H 1P3, Canada
[3] McGill Univ, Ctr Hlth, Dept Med, Div Clin Epidemiol, Montreal, PQ, Canada
[4] McMaster Univ, Sch Geog, Hamilton, ON, Canada
[5] Hlth Canada, Food Directorate, Ottawa, ON K1A 0L2, Canada
[6] McGill Univ, Dorval, PQ, Canada
[7] McGill Univ, Montreal, PQ, Canada
[8] Univ Toronto, Dept Geog, Toronto, ON M5S 1A1, Canada
[9] Univ Waterloo, Waterloo, ON N2L 3G1, Canada
[10] McGill Univ, Ctr Hlth, Montreal, PQ, Canada