Parental occupational exposure to pesticides and risk of childhood cancer in Switzerland: a census-based cohort study

Table 1 Characteristics at the time of entry into the Swiss National Cohort of the children included and excluded from analyses

Characteristics	Maternal exposure		Paternal exposure		Excluded from analysis¹
Characteristics	n	%	n	%	n	%
Total	1,807,902	100	1,700,149	100	172,974	100
Sex
Female	882,885	48.8	829,089	48.8	82,926	47.9
Children age at entry (years)
0–4	681,683	37.7	652,023	38.4	58,498	33.8
5–9	671,441	37.1	628,993	37.0	73,083	42.3
10–14	454,778	25.2	419,133	24.7	41,393	23.9
Education of reference person² in the household
Compulsory education or less	315,095	17.4	275,748	16.2	42,878	24.8
Upper secondary level education	929,231	51.4	873,756	51.4	50,403	29.1
Tertiary level education	543,703	30.1	538,377	31.7	23,921	13.8
Not known	19,873	1.1	12,268	0.7	55,772	32.2
Swiss-SEP³
Q1	480,442	26.6	447,167	26.3	54,900	31.7
Q2	371,151	20.5	349,556	20.6	34,861	20.2
Q3	343,012	19.0	323,173	19.0	28,202	16.3
Q4	322,421	17.8	304,985	17.9	22,717	13.1
Q5	275,612	15.2	262,061	15.4	16,620	9.6
missing	15,264	0.8	13,207	0.8	15,674	9.1
Degree of urbanization
Urban	422,132	23.3	375,466	22.1	55,893	32.3
Semi-urban	834,780	46.2	784,674	46.2	72,060	41.7
Rural	550,990	30.5	540,009	31.8	45,021	26.0
Parents’ occupational exposure to pesticides
High likelihood (≥70% of people exposed)	53,074	2.9	113,784	6.7	NA
Moderate likelihood (≥25 to 70%)	1233	0.1	30,717	1.8
Limited likelihood (≥10 to 25%)	31,838	1.8	104,304	6.1
No or minimal likelihood (< 10%)	1,721,757	95.2	1,451,344	85.4

Data represent number of children and column percentages (in italic). NA: data not available. P-values of chi-squared tests for differences between included and excluded children were < 0.001 for all socio-demographic characteristics)
¹Children were excluded from both analyses if neither their father nor mother could be identified or could not be assigned an exposure due to missing or non-classifiable job titles (Fig. 1)
²Person that contributes the most to the income of the household
³The SEP-index is an area-based measure of socio-economic position for Switzerland, estimated in neighbourhoods of 50 households with a principal component analysis of four socio-economic variables, with data from census 2000²⁶

ISSN: 1471-2407