## 1 Introduction
\begin{table}
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**Environmental Pollutants** & **Major Source of Emission** & **Average Time** & **Standard Level** & **Health Impact Target Organs** \\ \hline CO & motor engines, burning coal, oil and wood, activities, smokes & 1 h & 35 mg/m\({}^{3}\) & CNS and cardiovascular damages \\ \hline NO\({}_{2}\) & fnal combustion, burning coal & 1 h & 75 mg/m\({}^{3}\) & respiratory and CNS involvement, eye irritation \\ \hline UVB & sum, light bulbs, UV lamps & depending on the type of skin & 3-7; seek shade during daily hours & skin cancer, aging skin, age-related macular \\  & & skin & 8-11: avoid being outside during midby hours & & \\ \hline Sound loudness & vehicle, industry, traffic & 1 h & 60-70 dB & ear damage and hearing loss, CNS involvement, sleep disorder \\ \hline \end{tabular}
\end{table} 
Table 1: Standard level of environmental pollutants and their sources with health impact [26; 27]. diseases are among the leading causes of death [39]. Wearable devices support not only unobtrusive real-time and long-term monitoring of physiological parameters, vital signs, and motion activities but can also track ambient parameters from the environment [40; 41]. However, the required sensor integration and data fusion still is missing. For many diseases, and in particular for COPD, we need multi-functional, economic, and user-friendly wearables that are feasible in daily routine of clinical practice to identify individual's health status and its changes. Such devices should not be limited to a specific group of individuals but applicable to anyone and anywhere [42]. Nonetheless, previous works on wearable devices and technological platforms for the monitoring of COPD patients are either focused on physical activities, or physiology and vital signs, but only a few approaches actually combine several domains. Long-term physical activities are considered most, as body positioning and mobility indicate the health status [15]. Therefore, several works are published in this area, mainly utilizing accelerometers and gyroscopes [43; 44]. Contrarily, [PERSON] et al. developed an ear-worn prototype of pulse oximeter. The prototype is designed for low-cost, convenient, and long-term continuous monitoring. Technological, it is based on a vertical cavity surface emitting laser and shaped in style of hearing aids [45]. In \"VTAMN\" four electrodes for ECG and two for skin temperature measurement are combined with accelerometer and gyroscope for fall detection. Events are either launched manually by the patient or generated automatically from remote signal analytic for fall, hyper- and hypothermia, and tachycardia detection [46]. \"SweetAge\" is a distributed system that monitors heart rate, skin and near-body temperatures, and physical activity by a wrist band, which is connected via Bluetooth to a smartphone. A commercial pulse-oximeter is coupled as second component. The phone operates as gateway receiving data from the wearable sensors and transmitting it to the monitoring system [38]. Likewise, \"HealthWear\" is based on wearable garment with several textile-embedded biomedical sensors including 6-lead ECG, pulse rate, and respiratory movements and rate. Data is transmitted to a so-called portable patient unit (PPU). The PPU further connects external sensors such as an oximeter. All data is transmitted via the general packet radio service (GPRS) to a centralized server [47]. In Reference [48], motion activities, heart rate, and breathing rate are measured through a combination of wearable devices for vital signs and a camera for motion tracking and gesture detection. Heart rate and respiratory-induced intensity variation (RIIV) are extracted from a photo-plethysmographic headset. Data are transmitted via BLE to a personal computer (PC). [PERSON] et al. introduced \"CHRONIOUS\" as an integrated platform composed of several wearable devices.