Effect of short-term exposure to ambient nitrogen dioxide and particulate matter on repeated lung function measures in infancy: A South African birth cohort.

BACKGROUND: The developing lung is highly susceptible to environmental toxicants, with both short- and long-term exposure to ambient air pollutants linked to early childhood effects. This study assessed the short-term exposure effects of nitrogen dioxide (NO2) and particulate matter (PM10) on lung function in infants aged 6 weeks, 6, 12 and 24 months, the early developmental phase of child growth. METHODS: Lung function was determined by multiple breath washout and tidal breathing measurement in non-sedated infants. Individual exposure to NO2 and PM10 was determined by hybrid land use regression and dispersion modelling, with two-week average estimates (preceding the test date). Linear mixed models were used to adjust for the repeated measures design and an age*exposure interaction was introduced to obtain effect estimates for each age group. RESULTS: There were 165 infants that had lung function testing, with 82 of them having more than one test occasion. Exposure to PM10 (µg/m3) resulted in a decline in tidal volume at 6 weeks [-0.4 ml (-0.9; 0.0), p = 0.065], 6 months [-0.5 ml (-1.0; 0.0), p = 0.046] and 12 months [-0.3 ml (-0.7; 0.0), p = 0.045]. PM10 was related to an increase in respiratory rate and minute ventilation, while a decline was observed for functional residual capacity for the same age groups, though not statistically significant for these outcomes. Such associations were however less evident for exposure to NO2, with inconsistent changes observed across measurement parameters and age groups. CONCLUSION: Our study suggests that PM10 results in acute lung function impairments among infants from a low-socioeconomic setting, while the association with NO2 is less convincing.

Latent classes in diagnoses among psychiatric inpatients predicting mortality and imprisonment - a nationwide cohort study.

PURPOSE: Identify risk factors of death or imprisonment within classes defined by demographic factors and diagnoses within one year of first psychiatric admission. METHODS: Nationwide data was obtained from hospital registers from psychiatric hospitals in Iceland 1983-2007. Mortality and cause of death as well as information about imprisonments during the study period, and discharge diagnoses for the first year after initial admission were obtained for each individual. Individuals aged 18 during the study period with at least one year of follow-up were included. Latent Class Analysis was used to identify groups with distinguishable risk of either being alive, dead or having been imprisoned at the end of follow-up. RESULTS: Among psychiatric patients, 4677 were included, average age was 27 years (range 18-43). Four latent classes were identified with different risks of adverse outcomes. Class B (16%), predominantly males with substance use disorder (SUD) diagnoses, had highly increased risk of imprisonment and death accounting for 85 and 34% of these outcomes, respectively. Class A (12%), all with alcohol use disorder, had similar mortality rate as the general population and no imprisonments. Class C (23%) were younger at first admission with some SUD and increased risk of mortality. Class D (46%) had increased mortality rate, SUDs were rare but depression common. CONCLUSIONS: Risk of mortality and criminal trends among psychiatric inpatients can be described as distinct clusters of risk factors present at first admission to a psychiatric hospital. Treatment and interventions to reduce mortality and criminality should take these risk differences into account.