Ключевые слова: air, alarm, alert, atmosphere, atom, background, bio, biohazard, biologic, biological, caution, cloud, cloudscape, cloudy, contamination, danger, dangerous, energy, environment, epidemic, hazard, icon, industry, infectious, laboratory, nuclear, outdoor, radiation, radioactive, risk, rough, science, sign, sky, space, storm, stormy, summer, symbol, texture, toxic, virus, warning, weapon, weather, wind,