Costa Rica (1) Labor (1) Futures (1) Employees (1) Volcanoes (1) Urine (1) Surveys (1) Spectrophotometry (1) Sieges (1) Saliva (1) Research (1) Public officers (1) Population (1) Pollutants (1) Physicians (1) Pathology (1) National parks and reserves (1) Months (1) Methodology (1) Ions (1) Interviews (1) Indicators (Biology) (1) Health (1) Head (1) Hair (1) Gases, Asphyxiating and poisonous (1) Fatigue (1) Examinations (1) Evaluation (1) Diagnosis (1)