def get_aqi_level(row):
    """
    Computes the level of health concern based on a numeric value of the
    AQI index for a pollutant
    :param row: the AQI level of the pollutant
    :return: a string in ['good', 'moderate', 'unhealthy_sensitive_groups',
           'unhealthy', 'very_unhealthy', 'hazardous'] indicating the level
           of health concern
    """
    if 'AQI' in row['type']:
        if row['value'] <= 50:
            return 'good'
        elif row['value'] <= 100:
            return 'moderate'
        elif row['value'] <= 150:
            return 'unhealthy_sensitive_groups'
        elif row['value'] <= 200:
            return 'unhealthy'
        elif row['value'] <= 300:
            return 'very_unhealthy'
        else:
            return 'hazardous'
    else:
        return None