Air Quality and Ionizing Radiation During Travel

Air quality

Travelers, particularly people with underlying cardiorespiratory disease, should investigate the air quality at their destination. The AirNow website provides basic information about local air quality by using the Air Quality Index (Table 3.3.1). The World Air Quality Index project shows real-time air quality and air pollution data for more than 10,000 air stations in more than 80 countries around the world, and the World Health Organization posts historical data on outdoor air pollution in urban areas.

Dust masks, surgical masks, and bandanas offer limited protection against severely polluted air. When air is severely polluted (e.g., during wildland fires), the best protection strategies are to:

• Avoid prolonged time spent outdoors.
• Follow guidance or directives from local health or emergency management officials (see Wildfire Smoke Factsheet: Protect Your Lungs from Wildfire Smoke or Ash).

The U.S. National Institute for Occupational Safety and Health (NIOSH) approves respirators. A NIOSH-approved particulate respirator (e.g., N95 or P100 filtering facepiece respirators) can provide protection from breathing in harmful substances, including wildfire smoke, ash, and very small particles. Advise travelers with potential exposure to poor air quality outdoors to consider wearing a NIOSH-approved particulate respirator. While they may resemble other masks, these respirators are designed to form a seal to the face and have material that can filter out small particles such as particulate matter, smoke, ash, and mold spores. Parents should be aware that NIOSH does not currently approve respirators for children.

Travelers should be mindful of, and limit exposures to, outdoor and indoor air pollution (e.g., carbon monoxide [CO]; Table 3.3.2). Secondhand smoke from smoking tobacco is a primary contributor to indoor air pollution. Other potential sources of indoor air pollutants include ceremonial incense, candles, and cooking and combustion sources (e.g., kerosene, coal, wood, animal dung). These sources may also worsen asthma.

CO is an odorless, colorless gas that kills without warning. It claims the lives of tens of thousands of people every year worldwide and makes many more ill. Every year, a handful of U.S. tourists die from CO poisoning, typically in lodgings lacking CO detectors. Major sources of indoor CO include methane gas ranges and ovens, unvented gas or kerosene space heaters, fireplaces, and coal- or wood-burning stoves. A battery-operated or battery back-up CO detector, either portable or installed in a living space, can prevent CO poisoning. If the detector sounds, leave the living space immediately and call for emergency help. Check or replace the batteries on a routine basis, such as every spring and fall.

Table 3.3.1: Air quality index levels

Table 3.3.2: Strategies to mitigate adverse health effects of air pollution

Mold

Travelers might visit flooded areas as part of emergency, medical, or humanitarian relief missions. Water damage to buildings can lead to mold contamination. People with asthma or who are allergic to mold may have severe reactions. Immunocompromised people and people with chronic lung disease may get pulmonary infections from mold. To reduce exposures that could result in adverse health effects, travelers should avoid areas with visible mold contamination or odor and use personal protective equipment (PPE) such as gloves, goggles, waterproof boots, and NIOSH-approved particulate respirators. If the traveler plans to participate in activities such as ripping out moldy drywall, consider wearing a NIOSH-approved half-face or full-face respirator. To learn more about mold and respirators, see the Centers for Disease Control and Prevention (CDC) website, Respiratory Protection for Residents Reentering and/or Cleaning Homes That Were Flooded and Community Respirators and Masks.

Travelers should anticipate the environment to which they are traveling and bring enough PPE because supplies might be scarce or unavailable in the countries visited. Travelers should keep hands, skin, and eyes clean and free from mold-contaminated dust. For additional information, review CDC's recommendations for Mold Cleanup and Remediation.

Ionizing radiation

Exposure to radiation, especially ionizing radiation, raises concern for many people, even though background radiation is everywhere. This continuous radiation is from outer space, the ground, the air we breathe, and the food and water we consume.

Although the background exposure is continuous, it is not uniform and will vary with respect to location, altitude, and even seasonally. Despite this variability, no peer-reviewed studies have shown adverse effects from these exposures, even in those areas where the exposures are exceptionally high. Areas with naturally high radiation levels include Guarapari (Brazil), Kerala (India), Ramsar (Iran), and Yangjiang (China). Traveling to these areas does not pose a health hazard to travelers.

Although avoiding exposure to background radiation is not possible, areas exist where contamination from radioactive materials because of radioactive waste disposal or accidents is substantial; travel to these areas should be avoided by the public. Many of the disposal areas are controlled by national governments, have restricted access, and are usually situated in areas isolated from the public. The areas should be posted with warning signs. The warning signs used include the easily recognized trefoil symbol used in the United States (Figure 3.3.1, left) and a newer international symbol for radiation supplementing the U.S. sign (Figure 3.3.1, right).

Travelers who may be spending extensive periods of time (more than several months) in areas near these radioactive disposal areas should contact the U.S. embassy for information related to potential health issues in those areas. The requested information should include the safety of drinking water and food, including locally produced fruits, vegetables, meat, and prepared foods such as breads. For up-to-date safety information and current travel advisories for any country, see the U.S. Department of State's website on travel advisories or check with the U.S. embassy or consulate in the corresponding country. The U.S. Department of State's Smart Traveler Enrollment Program (STEP) permits U.S. citizens and nationals to receive safety alerts from the U.S. embassy; enrolling in STEP also enables the U.S. embassy to contact them in the event of an emergency.

Two areas of radioactive contamination where the radiation levels are considered too dangerous to visit are in Ukraine (Chernobyl) and Japan (Fukushima). These are sites of the world's largest nuclear power plant disasters. The lands surrounding these plants are contaminated with radioactive materials and will remain so for the foreseeable future. This poses a significant health risk to those living near, or traveling to, the areas.

The Chernobyl plant is about 100 km (62 miles) northwest of Kyiv, Ukraine, and 310 km (193 miles) southeast of Minsk, Belarus, on the banks of the Pripyat River. In 1986, the plant exploded and ejected radioactive material into the atmosphere. The radioactive contamination then deposited in many countries. One outcome of this accident was the increase in the incidence rates of childhood thyroid cancer. In a 7,000 km² (2,700 mi²) area, some buildings and roads had to be buried because they could not be decontaminated. In addition, some agricultural fields required extensive decontamination efforts. However, the area of greatest contamination continues to be in an area 60 km (38 miles) in diameter, centered on the Chernobyl power plant. This more than 2,800 km² (1,100 mi²) area is called the exclusion zone, where the ambient radiation dose levels range from 3 to 20 or more times greater than background levels.

The Fukushima Daiichi plant is located 240 km (150 miles) north of Tokyo. Following a tsunami in 2011, electrical power to the nuclear plant failed, resulting in explosions. Radioactive contamination was dispersed on land and into the ocean. The land area within a 20-km (12-mile) radius of the plant was evacuated. Japanese authorities also advised evacuation from locations farther away to the northwest of the plant. Because Japanese authorities continue to clean the affected areas and monitor the situation, access requirements and travel advisories change. The U.S. Department of State recommends against unnecessary travel to areas designated by the Japanese government to be restricted because of radioactive contamination.

Tours of the Chernobyl nuclear power plant and the Fukushima power reactor can be found online; however, the potential for radiation exposure and its long-term sequelae should be considered.

Fortunately, radiation emergencies are rare; however, their consequences can be extreme. In case of such an emergency, travelers should follow instructions provided by local authorities. If such information is not forthcoming, travelers should seek advice from their nearest embassy or consulate. The basic radiation protection measures include time (minimizing the amount of time one is exposed), distance (the further from the exposure, the lower the dose), and shielding (the more material between a person and the source, the lower the dose).

Natural disasters (e.g., floods) might displace industrial or clinical radioactive sources. In all circumstances, travelers should exercise caution when they encounter unknown objects or equipment, especially if the objects have the basic radiation trefoil symbol or other radiation signs (see examples; Figure 3.3.1). Travelers who encounter a questionable object should avoid touching or moving the object and should notify local authorities as quickly as possible. In addition to these objects, floods in the area of radioactive waste disposal areas may result in the dispersion of contamination into waters, soils, and sediments. Contact with these environmental media should be avoided.

Figure 3.3.1