Female students, as adolescent girls, are more at risk of anemia because of high nutritional requirements. Health education through mobile applications influences the knowledge, attitude, and practice (KAP) of anemia in adolescent girls. Based on our previous study, several adolescents experienced anemia. This study aims to analyze the effect of health education through mobile applications, namely the WANTER application, on increasing KAP. This study was quasi-experimental with a pretest–posttest design; the sample was divided into an intervention (WANTER application) and a control group (booklet). The study was conducted in a rural area of Indonesia. There were 162 adolescent girls included in the intervention group and as many as 115 adolescent girls in the control group. Our study showed that adolescents’ knowledge and attitude increased significantly in three months after the intervention of WANTER and booklets toward preventing anemia with p < 0.001; however, there was no significant difference in KAP between the control and intervention groups. In addition, there was no improvement in practice, either in the control or intervention groups. Knowledge, attitudes, and practices to prevent anemia need to be continuously improved. Health education through appropriate media for adolescents is very important to make interventions more effective.

The study aimed to compare air pollution levels in Jakarta, Indonesia before, during, and after the implementation of COVID-19-related restrictions on residents' activities. Data on air quality indicators such as PM2.5, PM10, nitrogen dioxide, and sulfur dioxide were collected and analyzed. The findings revealed significant variations in air pollution levels in response to the restrictions. Before the restrictions, air pollution levels were notably higher, attributed to increased industrial and vehicular activities. During the restrictions, there was a substantial decline in air pollution levels as a result of reduced human activities and transportation. After the restrictions were eased, air pollution levels began to rise again, albeit not reaching the same high levels as before. The study provides valuable insights into the impact of human activities on air quality and emphasizes the potential benefits of implementing policies to reduce air pollution. The findings contribute to the understanding of the environmental consequences of societal changes during the COVID-19 pandemic and have implications for future urban planning and air quality management in Jakarta.