Background: Air pollution is a severe problem in Poland, with Kraków area being among the regions with the worse air quality. Viral croup or pseudocroup is a common childhood disease that may manifest with severe upper respiratory tract obstruction. Our aim was to evaluate the associations between incidence and severity of viral croup symptoms among children living in Kraków area, Poland, and air pollution. Methods: Th e retrospective cross-sectional study included Kraków area residents <18 years of age admitted to the Emergency Department of St. Louis Children Hospital in Kraków, Poland over 2-year period. Daily mean concentrations of air pollutants: particulate matter (PM10 and PM2.5), nitric oxides (NOx), carbon oxide (CO), sulfur dioxide, ozone, and benzene were retrieved from public database of measurements performed at three local stations. Numbers of cases of viral croup per week were correlated with weekly mean concentrations of air pollutants. Mean air temperature was treated as a cofactor. Results: During the studied period, mean concentrations of PM10, PM2.5, and NOx exceeded the allowable levels (yearly means) specifi ed by Polish law regulations. Signifi cant positive correlations of moderate strength were observed between weekly mean concentrations of most air pollutants, especially PM10, PM2.5, CO and benzene, and numbers of cases of viral croup recorded per week, confi rmed in the analysis restricted to non-holiday period and to winter months only. Th e correlations between NOx, CO, benzene and croup prevalence were independent of temperature in non-holiday period. Conclusions: Our results support adverse impact of air pollution on children’s respiratory health.

Alcohol is a recognized teratogen that affects various aspects of fetal development. Tissue that is particularly susceptible to its teratogenicity is neuronal tissue. The effect of prenatal alcohol exposure (PAE) on the central nervous system has been extensively studied, yet the knowledge on the influence of PAE on the autonomic nervous system is scarce. The purpose of this article is to review the current state of knowledge about the impact of PAE on the autonomic nervous system. Studies conducted on the PAE animal model have shown that prenatal alcohol exposure is associated with significant alterations in the autonomic nervous system, but the mechanisms and consequences are not yet clearly defined. It was established that PAE causes decreased heart rate variability (HRV) in fetal cardiotocography. Several studies have revealed that later, in infancy and childhood, reduced parasympathetic activity with or without compensating sympathetic activity is observed. This may result in behavioral and attention disorders, as well as an increased predisposition to sudden infant death syndrome. Both animal and human studies indicate that the relationship between PAE and autonomic dysfunction exists, however large, well-designed, prospective studies are needed to confirm the causal relationship and characterize the nature of the observed changes.