Background: Many factors are associated with pedestrian injuries and accidents. If a pedestrian is injured in an outdoor public space, we are talking about a “pedestrian fall”. Pedestrian falls are a more common cause of pedestrian injuries than traffic crashes but have received less attention and the literature on this topic is scarce. Aims and methods: The aim of this work is to describe at a general level the prevalence and consequences of pedestrian falls and injuries, to make international comparisons of pedestrian falls and to identify risk factors and not least to examine the relationships between the prevalence of falls and pedestrian risk behaviour. A total of 6,373 participants from 15 different countries were recruited to take part in this study. To collect data a questionnaire was used. To cover the risky behaviour of pedestrians we used a short version of Pedestrians Behaviour Scale (PBS). In order to identify groups of countries with a similar pedestrian transport situation, a hierarchical cluster analysis was performed. The analysis produced four groups of countries based on pedestrians’ safety level, popularity of walking and GDP. Results and conclusions: As for the results, we can conclude that young people and older people are more frequently involved in falls and that women report more frequent involvement in falls than males. However, the risk of getting injured in a fall is not higher than that of men. Frequent walking is associated with a lower risk of falling while walking. In contrast to this, physical activity increases such risk. The prevalence of falls and injuries seems to be weakly related to pedestrians’ risky behaviour, thus other factors such as safety infrastructure probably play an important role.

A full-scale wastewater treatment plant in China experienced unintentional anammox bacterial enrichment on biofilm carriers placed in the anaerobic and anoxic zones of an anaerobic/anoxic/oxic process under ambient temperatures and without bioaugmentation. Here, we show that microaerophilic conditions resulting from air scouring needed for biofilm carrier suspension in the anaerobic/anoxic zones can support a robust nitritation/anammox process. Results from an in situ on/off air scouring test showed that air scouring strongly induced both ammonia and total inorganic nitrogen removal in the anaerobic/anoxic zones. Ammonium concentration in the anaerobic and anoxic tanks remained constant or even slightly increased when air scouring was off, indicating that air scouring made a noticeable difference in nitrogen profiles in the anaerobic/anoxic zones. Various batch tests further indicated that partial denitrification is not likely to generate nitrite for anammox bacteria. Robust nitritation, and anammox on the carriers, can occur at low dissolved oxygen conditions, as measured in the full-scale facility. The observations show that mainstream deammonification without sidestream bioaugmentation at moderate temperature is feasible and further optimization by a more dedicated design can result in improved nitrogen removal in cases when chemical oxygen demand is limited in mainstream wastewater treatment. Practitioner points: Microaerophilic conditions in a full-scale IFAS reactor caused mainstream anammox in moderate temperate area. Robust nitritation, and anammox on the carriers, can occur at low dissolved oxygen conditions in anaerobic/anoxic tanks with air scouring. Anammox can function well with conventional nitrification and denitrification process at mainstream conditions for stable nitrogen removal.