Child Labour and Health Outcomes- A Critical Review of Published Evidence 1988-2008

Introduction
Over 215 million children below 14 years of age work globally. Not all child labor is harmful. This comprehensive literature review assesses all accessible published evidence in scientific journals of health effects of child labor in the informal sector in developing countries 1988-2008.

Methods
Journal articles were identified in bibliographical databases: PubMed, OVID and World of Science. Keywords were: working children, child labor, employment, informal sector AND health. Two authors assessed abstracts and then articles. Articles that reported a scientific study on health outcomes in working children (age 14 and younger) from developing countries were included.

Results
The broadest search yielded 46,330 articles. However, abstract review yielded only 28 possible research studies. Most not-included publications were either not available/accessible, or were opinions/editorials, anecdotal or case reports or unclear convenience samples. Books or gray literature were excluded. Finally only 22 studies met inclusion criteria. Overall quality of was poor: 8 (36%) below 50%-quality score, 19 (86%) below 65%-quality. Majority were cross-sectional (10/22; 45%), very few qualitative studies. Common quality limitations were: poor design and methodology, cross-sectional study design, poor reporting, and unclear participants' selection. Eleven studies (50%) focus on nutrition and growth, only three reported physical injuries (14%), ten growth (45%), two mental health (10%) and three neurological outcomes (14%). Only one study each included biological monitoring or lung-function-tests. Some studies report improved [!] health and nutritional outcomes. All studies describe difficulties to recruit participants.

Discussion
Surprisingly few studies in 1988-2008 actually report scientifically on health effects. Overall quality of studies was poor. Access to journals in developing countries is still problematic. Impact of non-hazardous child work on health can be positive or negative. The global focus of ILO/IPEC on worst forms of child labor, abuse or social impact seems justified.