**E. Risks of hazardous substances for the ecosystem**

If pharmaceutical or chemical pollutants are released into the environment, they can easily diffuse through groundwater, surface water, and eventually leach into drinking water. Pharmaceuticals are discarded and renewed in healthcare facilities when they expire. In time of conflicts or natural disasters, large quantities of pharmaceuticals are often donated as a part of humanitarian assistance [26]. However, such donated pharmaceuticals are sometimes stocked and often mismanaged when the pharmaceutical management system is not well functioned. Disposal of these unwanted or expired drugs may disturb the ecosystem. WHO guidelines [1, 27] recommended pharmaceutical waste to reverse distributors.



#### **Table 1.**

*Problems recognized in HCW management and challenges for solving them.*

#### **3.3 Problems and challenges in HCW management**

The above-mentioned five risks are caused by 14 problems in HCW management, and the relationship between the risks and problems is depicted as a causal linkage diagram as shown in **Figure 6**. The description of each problem and the challenges

for enhancing HCW management, which indicate the goal of technical assistance, are summarized in **Table 1**. If HCW waste is not properly segregated at the source (Problems No. 1–4), it creates many risks associated with various technical and management factors in the HCW management process (No. 5–14).
