Table 1.

Descriptive Characteristics of 350 Boys With Serum Organochlorine Pesticide Measurements at Entry Into the Russian Children's Study, 2003–2005

Characteristic	Median	Range	No.	%
Physical characteristics
Height, z scorea	0.14	−0.58, 0.77b
Body mass indexc, z scorea	−0.31	−1.01, 0.51b
Overweight			36	10
Obese			22	6
Birth and neonatal historyd
Birth weight, kg	3.4	3.1, 3.7b
Gestational age, weeks	40	38, 40b
Duration of breastfeeding, weeks	13.0	4.3, 30.3b
Breastfed			297	85
Boys’ daily dietary intakesd
Total calories	2,520	2,039, 3,256b
Calories from carbohydrates, %	55	50, 59b
Calories from fat, %	34	30, 38b
Calories from protein, %	11	10, 12b
Boys’ daily physical exercise levelsd
None			109	31
<2 hours/day			124	36
≥2 hours/day			116	33
Household characteristicsd
Maximum parental educational level
Secondary education or less			29	8
Junior college/technical training			198	57
University graduate			121	35
Household income
<$175/month			107	31
$175–$250/month			88	25
>$250/month			154	44
Serum organochlorine pesticides
Lipid-standardized measures, ng/g lipid
Hexachlorobenzene	162	80, 392e
β-Hexachlorocyclohexane	165	81, 407e
p,p′-Dichlorodiphenyldichloroethylene	288	122, 835e
Wet-weight measures, ng/g
Hexachlorobenzene	770	383, 1,973e
β-Hexachlorocyclohexane	800	405, 2,078e
p,p′-Dichlorodiphenyldichloroethylene	1,410	596, 4,106e

^a World Health Organization age-adjusted z scores (21).

^b Values represent the 25th and 75th percentiles.

^c Weight (kg)/height (m)².

^d Missing information on birth weight (n = 1), gestational age (n = 2), whether or not breastfed (n = 5), dietary intakes (n = 3), physical activity (n = 1), parental education (n = 2), and household income (n = 1).

^e Values represent the 10th and 90th percentiles.