Parental occupation is a risk factor for childhood wheeze and asthma

Abstract

The present birth cohort study investigated whether or not childhood wheeze and asthma are associated with parental exposure to occupational sensitisers that cause asthma.

Parental occupation, from the Avon Longitudinal Study of Parents and Children (ALSPAC), was related to wheeze, asthma, ventilatory function, airway responsiveness and atopic sensitisation in children aged 0–102 months.

Occupation was recorded for 11,193 mothers and 9,473 fathers antenatally, and for 4,631 mothers and 5,315 fathers post-natally. Childhood respiratory outcomes were not associated with parental occupational exposure to diisocyanates, glues/resins, dyes, animal dust, solder, enzymes and wood dust. Maternal post-natal occupational exposure to latex and/or biocides/fungicides increased the likelihood of childhood wheeze and asthma. High levels of latex or biocide/fungicide exposure were associated with an OR (95% CI) of 1.26 (1.07–1.50) and 1.22 (1.02–2.05), respectively, for wheezing up to 81 months. Combined maternal latex and biocide/fungicide exposure increased the likelihood of childhood wheeze (1.22 (1.03–1.43)) and asthma. High paternal occupational flour dust exposure was associated with an increased likelihood of wheeze after 30 months (2.31 (1.05–5.10)) and asthma by 91 months (3.23 (1.34–7.79)).

Maternal occupational exposure to latex and/or biocides and paternal exposure to flour dust increases the risk of childhood asthma. Further studies in this area are justified.
Occupational exposures are an established risk factor for asthma, accounting for 5–25% of incident asthma in working adults 1–3. Para-occupational asthma has also been described, e.g. cases of asthma caused by exposure to toluene diisocyanate in people not directly working with this chemical but working in the vicinity of factories using toluene diisocyanate 4. Para-occupational exposure of children via parent(s) to asbestos, pesticides and organic solvents with health sequelae has been described 5–8. There is also evidence that occupational allergens can be transported home, presumably on contaminated clothing and skin, with subsequent atopic sensitisation of other household residents 9–12.

Based on these observations, it was hypothesised that parental exposure to common occupational sensitisers increases a child's risk of developing asthma and respiratory symptoms. This hypothesis was tested in the Avon Longitudinal Study of Parents and Children (ALSPAC), which prospectively collected data on parental occupation and childhood respiratory symptoms/asthma. Certain maternal occupations during pregnancy have been reported to increase the risk of asthma and allergic disease in older children 6. The ALSPAC cohort permitted the investigation of possible effects of maternal antenatal and also post-natal occupation on the likelihood of childhood respiratory symptoms and asthma.