Table 1

Maternal and child characteristics, Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), CA, 1999–2000 (n=279)

Child’s sex
Season of birth*
Breast feeding duration
 Never breastfed134.7
 ≤6 Months12845.9
 >6 Months13849.5
Mother’s country of birth
Maternal education
 ≤6th Grade12344.1
 7–12th Grade9734.8
 Completed high school5921.1
Maternal history of asthma
Mother smoked during pregnancy
Home ≤150 m from highway 101 (6 or 12 months)
Mean daily PM2.5 near home (0–3 months)
 <8 μg/m312645.2
 8–12 μg/m312143.4
 ≥12 μg/m33211.5
Signs of moderate/extensive mould at home visit (6 or 12 months)
Pets at home at ages 5–7
Agricultural workers in the household at age 7
Food insecurity status at age 7
 Food secure17462.4
 Food insecure with or without hunger10537.6
  • *Season of birth corresponds generally to other potential exposures that might play a causal role in respiratory disease. We defined the seasons as follows: pollen (mid-January to mid-May 2000), dry (mid-May to mid-August 2000), mould (mid-August to mid-January 2001), wet (mid-January to mid-March 2001), pollen (mid-March to mid-May 2001) and dry (mid-May to October 2001). Differences in the date of seasons across years are based on actual rainfall and measured pollen counts for that year.