6
EXISTING DISTRIBUTION PLANS FOR POTASSIUM IODIDE

Various governments have decided to distribute KI to protect populations against exposures to radioactive iodine in connection with nuclear facilities; others have decided not to distribute it. This chapter reviews US and international experiences in deciding to distribute KI and implementing those decisions. It emphasizes factors important to consider when contemplating whether and how to distribute KI. First, the international experience is discussed, beginning with international guidelines and recommendations for countermeasures. The development of countermeasures to mitigate radioiodine exposures in the event of a release by various countries is then outlined, followed by details on how various countries have made KI available. The US experience is then discussed, starting with recommendations made by public-health institutions regarding KI distribution and the roles and guidance of the involved federal



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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident 6 EXISTING DISTRIBUTION PLANS FOR POTASSIUM IODIDE Various governments have decided to distribute KI to protect populations against exposures to radioactive iodine in connection with nuclear facilities; others have decided not to distribute it. This chapter reviews US and international experiences in deciding to distribute KI and implementing those decisions. It emphasizes factors important to consider when contemplating whether and how to distribute KI. First, the international experience is discussed, beginning with international guidelines and recommendations for countermeasures. The development of countermeasures to mitigate radioiodine exposures in the event of a release by various countries is then outlined, followed by details on how various countries have made KI available. The US experience is then discussed, starting with recommendations made by public-health institutions regarding KI distribution and the roles and guidance of the involved federal

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident agencies. Before the September 11, 2001, attacks, few states were prepared to distribute KI to the general population. After the attacks and the offering of KI by the Nuclear Regulatory Commission, several states began KI distribution programs. The decisions of states regarding whether to distribute are discussed with the experiences of the states that decided to distribute KI. The chapter then discusses the elements of state distribution programs, highlighting options and limitations to consider in planning such programs. Finally, some obstacles to and limitations of distribution efforts are summarized with observations regarding improvements to overcome them. International Experience with Potassium Iodide and Other Countermeasures in Nuclear Emergency Guidelines and Database The International Atomic Energy Agency (IAEA) and the World Health Organization (WHO) have published general recommendations for countermeasures in the case of a nuclear emergency: the International Basic Safety Standards for Protection Against Ionising Radiation and for the Safety of Radiation Sources (IAEA, 1996) and the Guidelines for Stable Iodine Prophylaxis Following Nuclear Accidents (WHO 1989, Update 1999). However, radiological emergency preparedness and rules for countermeasures differ from country to country. The Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development (OECD) initiated a questionnaire-based evaluation of short-term countermeasures in March 2001. The results of this evaluation have recently been published under the title Short-term Countermeasures in the Case of Nuclear or Radiological Emergency (NEA/OECD, 2003)1. The NEA distributed questionnaires to its 22 European and 6 non-European member countries. It received 15 completed questionnaires—from Australia, Canada, the Czech Republic, Finland, Germany, Hungary, Ireland, Japan, Luxembourg, the 1   The report is available at the OECD/NEA publication services (email: neapub@nea.fr).

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Netherlands, Norway, Sweden, Switzerland, the United Kingdom, and the United States. Results of the NEA/OECD evaluation, which included general approaches for short-term countermeasures and more specific information on evacuation, sheltering, and iodine blockade will be the primary basis for the discussion of the international experience in KI distribution in this chapter. This is supplemented with data from other reports from Germany, France, and other countries. General Approach to Countermeasures All countries responding to the NEA/OECD questionnaire consider evacuation, sheltering, and administration of stable iodine the preferred short-term countermeasures in areas close to an emergency site. The planning zone for evacuation is generally an area some 10 km (6.2 miles) in radius around the NPP, whereas the planning zones for sheltering and stable iodine are generally larger—a radius of 10-20 km (6.2-12.4 miles). This indicates that sheltering and use of stable iodine administration may be implemented together. The decision to implement the different countermeasures is based on non-uniform criteria, such as the safety status at NPP, results of radiation monitoring on site and in the vicinity, the meteorological situation, the actual release of radioactivity, and, most important, the dose expected or the dose likely to be averted by the protective measures. Interestingly, the timing of countermeasures is handled differently in different countries: some countries do not expect to implement them consecutively, but other countries plan to implement them first for the nearby areas and for specific populations (such as pregnant women and schoolchildren) and then address the remaining populations and areas further out. In developing emergency-plan guidelines and procedures, the responsible organizations have considered various factors. Table 6.1 shows that the most important factor in all countries is the time necessary to implement countermeasures, followed by public-health risk, the shielding qualities of average houses, and the public trauma induced by emergency measures.

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Table 6.1 Considerations for Emergency Plan Guidelines Factors Countries Australia Canada Czech Republic Finland Germany Hungary Ireland Japan Luxemburg Netherlands Norway Sweden Switzerl and United Kingdom United States Public health risk X X X X X X X X X X X X X X X Time necessary for the implementation X X X Xb X X X X X X X X X X X Shielding qualities of average houses X X X   X X   X X X X X X X X Availability of basement and shelters     X   X     X X X X   X     Transportation availability     X   X     X X X X X X X   Public trauma   X X     X X X X X X X X X X Night or day     X   X     X X X X   X     Nuclear power plant near a border     X   X X     X   X X X     Costs   X X     X   X X   X - - X X Countermeasur e applied to entire population   X X   X X X X X Xc X X X     Other:         Xa         Xd   - -     aOnly for evacuation. bStable iodine and sheltering could be only for children. In the case of evacuation, if there is not enough time or transport facilities, pregnant women and children first. cWeather conditions. dWeather conditions and number of people involved. Source: NEA/OECD, 2003. For most European countries, the IAEA International Basic Safety Standards is the basis for radiation-emergency planning. Recently, the WHO Guidelines for Stable Iodine Prophylaxis Following Nuclear Accidents, which were updated in 1999, were implemented by many countries. In Germany, a country with a federal constitution comparable with that of the United States, general guidelines are laid down in the Basic Recommendations for Disaster Preparedness in Areas Surrounding Nuclear Facilities (The German Minister for the

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Environment, Nature Conservation and Nuclear Safety 1999). These guidelines were approved by the Conference of Ministers of the Interior of the Federal States, and the responsible organizations of the states (county district magistrates or district authorities) developed procedures for the implementation of short-term countermeasures. Evacuation According to the IAEA International Basic Safety Standards a generic optimized intervention level of 50 mGy (5 rad) of avertable effective dose in a period of no more than 1 week is recommended for temporary evacuation, that is, evacuation is indicated when the action averts a dose greater than this level. The national intervention levels for evacuation differ considerably, with intervention levels for most countries falling within a wide range of anticipated effective dose: 30-500 mGy (3-50 rad), typically with an integration time of 7 days. Timely evacuation offers the highest degree of protection against external and internal exposure. If evacuation cannot be finished in the pre-release phase, sheltering may be more effective. Evacuation, compared with sheltering or iodine blockage, however, can have more severe psychological, social, and economic consequences. Sheltering According to the IAEA International Basic Safety Standards, for sheltering the generic optimized intervention level is 10 mGy (1 rad) of avertable effective dose2 in a period of no more than 2 days. Staying indoors is a relatively simple way to reduce external or internal radiation exposure in the event of an emergency. Protection against external radiation depends strongly on the shielding capabilities of the building and the building material used. People should use cellars or protection rooms of solid construction. 2   The committee discussed and decided to use the term "avertable dose" for its recommendation (averted dose addresses the same issue). This decision follows the recommendations of the International Committee on Radiological Protection given e.g. in publication No. 60.

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Windows and outer doors have to be closed, and ventilation systems must be shut down. For a sheltering period of 24 h or longer, food, water, and medical care should be provided. Long-term sheltering may cause social, medical, and hygiene problems. The variation in intervention levels used for sheltering is smaller than that in other countermeasures (evacuation and iodine blockage). Generally, the recommendations of the IAEA International Basic Safety Standards are followed. For almost all countries, sheltering is implemented as the initial countermeasure because it is easy to organise and the compliance of the population is expected to be relatively high. During sheltering, people are easy to find if it is decided to use iodine blockage. In fact, sheltering is usually combined with the administration of KI. In some countries, the recommendation that children stay indoors is used as a “lighter” countermeasure. Iodine Blockade Iodine blockade will rarely be used as a stand-alone protective action. It normally is combined with sheltering or evacuation. All countries recommend the additional use of stable iodine when inhalation of radioiodine is the major exposure pathway. In the case of ingestion of contaminated food (such as milk and leafy vegetables), however, restricting the production and consumption of foodstuffs will be more effective (WHO, 1999). Dose criteria used to initiate iodine blockade in the 14 countries that completed the NEA questionnaire are summarized in Table 6.2. In nearly all countries, KI is the preferred chemical form for administration of stable iodine, but three countries use potassium iodate (KIO3). The dosages, administration mode, and duration of iodine blockade used by different countries are shown in Table 6.3.

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Table 6.2 Criteria for Stable Iodine Intervention Country Intervention level Dose type at intervention level Dose integration time Operational intervention criteria Australia 100 mGy Averteda dose   Under review at present Canada 100 mSvb Thyroid organ dose (averted dose)   c Czech Republic 5–50 mSv 50–500 mSv Effective dose Organ dose (averted)   0.1 mSv/hd Finland 10 mGy (for children under 18) 100 mGy (for adults) Averted dose to the thyroid   10 μSv/h (for children under 18) 100μSv/h (for adults) Germany 50 mSv (for children up to 18 and pregnant women) 250 mSv (for adults up to age of 45) Thyroid organ dose (anticipated) Radioactive iodine inhaled over a period of 7 days including dose equivalent commitment Criteria are given for released activity of iodine at the source and time integrated air concentration (see Annex A) Hungary 100 mGy Thyroid organ dose (averted)   0.1 mSv/h; 4 h plume transitione Ireland 100 mSv Anticipated averted thyroid dose   Thyroid dose from radioiodines Japan       Where a high thyroid dose is anticipated, stable iodine prophylaxis taken according to judgement of experts. Luxembourg 30–250 mSv (children) Anticipated organ dose     Netherlands 250 mSv (for children < 17 and pregnant women) 1000 mSv (for adults) Projected thyroid dose     Norway 100 mGy Averted dose     Sweden 10–100 mGy (for children) Averted dose to the thyroid     Switzerland 30–300 mSv Organ dose (anticipated dose) Inhalation dose integrated over time of plume passage Source term estimation United Kingdom 30–300 mSv Committed thyroid dose, averted by countermeasure   Varies with site/operator United States 5 Gy (for adults over 40 yrs) 100 mGy (for adults 18-40 yrs) 50 mGy (for pregnant/lactating women and those under 18 yrs) Committed dose equivalent to thyroid     a The averted (or avertable) dose is the dose to be prevented by the particular protective action (i.e., the difference between the dose to be expected without stable iodine blockade and that to be expected with it). b Health Canada’s Federal Recommendation. The province of Quebec has other intervention levels: 50 mSv. (0–20years), 100 mSv (20–40 years). c To be developed. d The default value of several ten mSv/h will be used, depending on real course and conditions of radionuclides release; for calculation the averted dose of 100 mSv from inhalation was used as basis assumption, and various accident sequences for WWER-213 reactor were calculated to assess the possible consequences for country specific conditions. e To be included into the National Nuclear Emergency Plan being revised, not yet accepted. Source: NEA/OECD, 2003. The table shows that different countries use different dose units.

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Table 6.3 Dosages of Stable Iodine Recommended for Radioiodine Prophylaxis Country Populationa Dosage (mg) Frequency Duration Mass of KI Mass of iodine Australia Infants   25–50 Single dosage   Children 50 Single dosage Adults 100 Single dosage Pregnant women 100 Single dosage Emergency Workers 100 1 per day 10 days Canada Neonates   12.5b c c Infants 25b   Children 50b Adults 100b Czech Republic Infants 32   24 h 16 mg 48 h Children 65 24 h 3.5 mg 48 h Adults 130 24 h 65 mg 48 h Pregnant women 130 24 h max. 2x Others 130   Finland Neonates 16   d 24 h Infants 32.5   Children 65 Adults 130 Pregnant women 130 Germany Neonates 12.5   Normally single dosage. In exceptional cases taking an additional tablet may be recommended The intake for neonates should be confined to one day. Infants 25 Children 50 Adults 100 Pregnant women 50 Hungary Infantse 65   Twice daily 10 days Childrene       Adultsf Pregnant womene Ireland Neonates   12.5 (1/4 tablet)   One day Infants 25 (1/2 tablet)   Children 50 (1 tablet) Adults 100 (2 tablets) Pregnant women 100 (2 tablets) Japan Infants 50   50 mg/day Max. 10 days; Children 100 100 mg/day Adults 100 100 mg/day Less than 1 g (total) Pregnant women 100 100 mg/day Luxemburg Neonates   12.5 1 Only 1 dosage Infants 25   2 days Children 50 2 days Adults 100 2 days Pregnant women 100 Only 1 dosage Netherlands 0-4 year KIO3 25 Normally single dosage. In exceptional cases taking an additional tablet may be recommended Only during the passage of the plume. Normally, ‘clean’ food can be supplied 5-16 year   50 > 16 year 100 Pregnant women 100 Norway Neonates 16   d 24 h Infants 32.5   Children 65 Adults 130 Pregnant women 130

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Country Populationa Dosage (mg) Frequency Duration Mass of KI Mass of iodine Sweden 0-1 month 16   Normally single dosage. In the case of prolonged release, an additional dosage may be recommended   Infants < 3yrs 32.5 Children < 12 yrs 65 Adults < 40 yrs 130 Pregnant women 130 Switzerland Neonates 16.2   Single dosage Only one time Infants 32.5 Single dosage Only one time Children 65 Per day g Adults 130 Per day a Pregnant women 130 Per day Max. 2 days United Kingdom Neonates   12.5 Single administration only, preferred Single administra tion provides protection for 24 hours Infants 25 Children 50 Adults (including pregnant and lactating women) 100 United Statesh,i Birth through 1 mo 16   Until risk of significant exposure to radioiodin e by either inhalation or ingestion no longer exists 1 mo through 3 yrs 32 Children 3-12 yrs Adults 12-18 yrs 65 Adults over 18 yrs Pregnant/lactating women 130 a Neonates: birth–1 month old Infants: 1 month–3 years old Children: 3–12 years old Adults: include adolescents aged 13–16 years old b Federal recommendation follows the 1989 WHO Guidelines. Varies by province. c Varies by province. In New Brunswick, the frequency is 1 dosage per 24 hr (except for newborns, where a single dosage is advised), until instructed to stop. At the federal level, a protracted dosage is generally not advised d If needed, authorities give an order for another dosage after 24 h e ½ or ¼ may be administered depending on age or in case of iodine sensitivity f Adults under 40 years old g The duration depends on the actual situation hIn the United States, the plume phase exposure lasts 24 hours or less due to evacuation being the primary protective action. KI is provided to address plume exposure and one dose should be taken to address the first 24 hour period during which time evacuation is occurring. iIt is assumed throughout this report that the need for administration of KI is necessary only once and to protect the thyroid gland against inhalation of radioiodine from a passing plume (cloud) and that further protection from radioiodine will be accomplished by evacuation and control of contaminated milk and other foods. Source: NEA/OECD, 2003. For practical use of iodine the pharmacological shelf life of predistributed tablets is of interest. Table 6.4 summarizes how the shelf life for stable iodine tablets is taken into account by different countries.

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Table 6.4 Assumed Stable Iodine Tablets Shelf-Life Country Assumed Shelf-Life for Stable Iodine Tablets in years KI KIO3 Australia 5a   Canada 5   Czech Republic 5   Finland 5   Germany 10–15   Hungary 5   Ireland   5 Japan     Luxemburg 10   Netherlands   Check every 5 years Norway 5   Sweden 5   Switzerland 8   United Kingdom   3 aAfter 5 years, the tablets are tested; depending on result, shelf-life might be extended. Source: NEA/OECD, 2003. Information about possible side effects of iodine tablets is presented in leaflets that are distributed by most of the countries to households in EPZs before an emergency. In Luxembourg, people who may suffer severe side effects from a large dosage of stable iodine or who have thyroid disease are invited to consult their doctors in advance. In Germany, two types of leaflets are distributed: one to households and the other to family doctors. The German information about possible side effects and countermeasures for family doctors reads as follows: Persons with a known hypersensitivity to iodine (very rare disorders, such as genuine iodine allergy, dermatitis herpetiformis Duhring, iododerma

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident tuberosum, hypocomplementaemic vasculitis, myotonia congenita) must not take iodine tablets. In rare cases, iodine tablets may also lead to skin rashes, edema, sore throat, watering eyes, nasal catarrh, swelling of the salivary glands and elevated temperature. In very rare cases, signs of hypersensitivity to iodine (genuine iodine allergy), e.g. iodic rhinorrhea or iodic rash, may be observed. However, the possibility of intolerance to iodine should not be overrated. Absorption of iodine by the body can be inhibited by gastric irrigation with starch solution (30 g to 1 litre until blue colour disappears) or with a 1-3% solution of sodium thiosulphate. Administration of Glauber’s salt and forced diuresis are recommended to speed up excretion. Any shock and any water and electrolyte disorders are to be treated according to guidelines well known by physicians. In cases of a previous history of thyroid disorders, even if its course has been so far asymptomatic (especially in case of nodular goiter with functional autonomy) hyperthyroidism may be triggered within weeks or months after administration of iodine. If stable iodine is contraindicated because of the reasons mentioned, the most suitable medication apart from iodine is perchlorate, which competitively inhibits the uptake of iodine. The following dosage is recommended for adults: Sodium perchlorate (as Irenat®): on first day 60 drops, thereafter 15 drops every 6 hours for seven days (15 drops = 345 mg). Contra-indications such as hypersensitive reactions (agranulocytosis) and serious liver damage must be watched for.

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident One of the most effective predistribution programs with respect to reaching residents that came to the committee’s attention was that of Calvert County, Maryland. This county, the fastest-growing county in Maryland, has a population of 75,000, with 35,000 residents within the 10-mile vicinity of the NPP. The county relied heavily on the public schools and other facilities for distribution, using school mails to disseminate information to families, health-department mails to inform designated facilities for KI placement, and the local print and television media to alert residents. From April to June, 2002, KI was placed in 97 schools and other facilities for distribution to the public. Five Saturday clinics were held at two high schools to inform and distribute to families that had been identified through the elementary-school network, and two additional clinics were held at the high school and four at the health department for the general public. The public was also encouraged to visit the county health department. Home visits were made to the homebound. KI reached about 24,400 of 35,000 residents living within 10 miles of the Calvert Cliffs NPP: 2,421 households covering some 11,450 people reached by the school framework and about 12,955 people reached via other facilities (a large LNG plant, 65 small workplaces, senior facilities and nursing homes, and day-care centers). Those reached by the school framework received two tablets per person, and those reached through other facilities received one tablet per person. The cost of the Calvert County predistribution program was fairly low, totaling $13,126 for county health-department staff and printing and mailing. That corresponds to $0.55 per person reached. In response to the committee’s request for information, limitations in the plan were noted. The major limitations have to do with resources, which were characterized as “sorely limited”. That affects the evaluation and monitoring of the distribution program, the degree of public education and outreach, the general management of the distribution and related programs, and access to people who may not be aware of the program but might wish to obtain KI. It was noted that federal resources, if made available, would best be applied to fund staff to support the plan, assist in distribution, carry out public education and outreach, and evaluate the program. It was felt that additional federal guidance was unnecessary and that local

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident jurisdictions and states were the best equipped to plan and execute KI distribution because of their familiarity with the affected communities. Elements of State Distribution Programs The differing experiences and implementation plans of Connecticut, Maryland, Tennessee and other states (see Appendix C) highlight options and limitations to consider in planning distribution programs, as discussed below. Predistribution with Postincident Stockpiling. All states on which the committee had detailed information about predistribution programs also had extensive plans for stockpiling and postincident distribution. Target Population. All states target predistribution efforts to those living in the 10-mile EPZ. The Nuclear Regulatory Commission decision to offer KI dosages to the general public in the 10-mile EPZ no doubt was a dominant factor in producing this uniformity. Some states are evaluating populations beyond the 10-mile radius. States with predistribution programs currently distribute or offer KI to the entire population; age has not been a factor in predistribution of KI, despite the fact that children and pregnant women with fetuses in the second and third trimester of pregnancy are at most risk. States’ stockpiling programs also target the general and special populations in the 10-mile EPZ. Some states attempt complete coverage of the entire population that may be present in the EPZ during an emergency, others a specified fraction of those residing in the EPZ (such as Tennessee), while others decided to use the residual KI not distributed in predistribution programs for stockpiling and distribution in the event of an emergency. Advice on Dosages. The complexity of the public health message that must be given to mitigate overdosages and ensure adequate dosages appears to have contributed to the oversimplified dosages information given by some state programs. Different dosages

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident messages and advice are used by the states. Some states (such as California, Massachusetts, and South Carolina) recommend dosages at the recent FDA (2001a) guidance levels for minimum effective dosage (see Table 6.11). Others (such as Ohio and New York) found that a scheme of graded dosages would be difficult to implement during a radiologic emergency. Some noted that adherence to the FDA minimum effective-dosage guidance should be followed where feasible, but compliance would be more likely if the simple instruction for two dosages (Dosage Message 2 in table 6.11) were given. Vermont recommended the administration of one tablet to children above 3 years old in such settings as schools, and ½ tablet to those under 3. Several states appear to be unaware of the important precautions regarding overdosing neonates given in the FDA 2001 guidance (see section above Recommendations from Public Health Institutions in the U.S.). This may result from the interpretative guidance and fact sheets issued by the FDA (2001b, 2002, 2003c); they all emphasize the benefits of KI compared to the risks of overdosage, and none discuss TSH monitoring of neonates after KI dosage, as recommended in FDA (2001a). An example of the confusion in the FDA guidance on dosing is provided above in discussion of Connecticut’s distribution program.

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Table 6.11 Dosages recommended by States Dosage Message 1 1 tablet = 130 mg Adults 18 years and older 1 tablet Pregnant or nursing women 1 tablet Adolescents 12-18 years old ½-1 tablet Children 3-12 years old ½ tablet Children 1 month-3 years old ¼ tablet Infants—birth-1 month old 1/8 tablet Dosage Message 2 1 tablet = 130 mg Children over 1 year old and adults 1 tablet Children under 1 year old ½ tablet Number of Tablets to Predistribute. Some states provided two dosages per person, others (such as New York) provided one dosage. One state provided two tablets per individual residing in households identified and reached via schools and one tablet per individual in households reached by other facilities. In this case, a greater proportion of children compared to adults would be expected to have multiple tablets available to them. States stockpile and reserve for post-accident distribution the tablets not predistributed. Inefficient predistribution programs (ones who do not manage to predistribute most of the KI they plan to) following this strategy could be expected to have an adequate supply for a single day of post-distribution. Connecticut, with its efficacious predistribution program, purchased additional KI tablets to ensure adequate supply for stockpile and postdistribution.

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Method of Predistribution. The efficacy of the voluntary-pickup predistribution program appears to depend heavily on the methods used, the intensity of community and stakeholder involvement in planning and distributing KI, public-education materials and messages, and mass-media involvement (Table 6.12). The general methods used have included door-to-door distribution (as was done in 1981 in Tennessee), mass mailing of tablets and information on use (Connecticut), request by mail after mass mailing (California), formal application for KI via a mailed application (some involving an informed-consent form), and pickup at identified locations in the community on particular “KI days.” Some states routinely provide residents information on the predistribution and make KI available to persons moving into the EPZ after the initial distribution. States’ programs of voluntary pickup by residents at specified locations generally resulted in distribution to no more than 5% of residents. In addition to the door-to-door distributions of Tennessee in the early 1980s, other means appear to have been effective. KI reached 2/3 of the effective population in a program involving mass mailing accompanied by publication and public education effort, and a well-orchestrated distribution through schools and local facilities (Calvert County, Maryland).

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Table 6.12 Coverage of Some Predistribution Programs State Predistribution Method Coverage Statistics California Mass mailing of brochures including postcard to request KI; mass-media campaign KI distributed to 31.7% residents ordering Connecticut 450,000 tabletsa Mass mailing of tablets High Illinois 360,000 tablets KI made available for residents to pickup at distribution stations 6% of eligible population requested KI Maryland Other counties Predistributed to local residents through clinics; continuing distribution through local health-department offices State estimates that 25% of eligible population obtained KI Calvert County Voluntary pickup; distributed to general population through schools, workplaces, other facilities 70% New Hampshire 350,000 tabletesa Requires submitting application available at town halls, and health-department offices, over Internet 3.5% New Jersey 722,000 tabletsa KI made available at designated locations via “public education and distribution” sessions About 10% New York 1.2 million tablets Distribution varied by county; provided locations for pickup, pickup via mail 15% of population in EPZ North Carolina 750,000 tabletsa Voluntary pickup 35% of public picked up tablets Ohio Mass mailing of information letter with coupon for KI pick-up; mass-media campaign 40% of amount received was distributed Pennsylvania for 640,000 people Voluntary pickup About 34% Tennessee Voluntary pickup <5% Vermont Application required for distribution <5% aTablets requested.

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Predistribution to Schools and Workplaces. States have varied in their approach to predistribution and requirements of consent forms for postincident administration of KI at day-care facilities, schools, and workplaces. Some leave it to school districts and workplaces to design programs for distribution. Others have standardized education materials, methods for distribution, and consent materials. Education and Communication Strategies. Distribution programs with extensive public education and use of mass media appeared to be much more effective than those without. Structuring, implementing, and sustaining a public-awareness campaign appear to be necessary elements of a predistribution program. Provisions for Special Populations Difficult to Evacuate. One state has plans for early evacuation of nonambulatory residents. Several states have plans to administer KI and to shelter in place at prisons, hospitals, and nursing homes. One state routinely identifies the homebound and has plans for distributing KI to them. Morbidity and mortality associated with evacuating segments of special populations were important considerations in state decisions on strategies for their protection. Packaging and Labeling of KI Tablets. Because the tablets are issued by the Nuclear Regulatory Commission in blister packages of 14 tablets each, repackaging for distribution is necessary. Information with the packages can include the identity of the drug, the dosage, and precautionary messages. The Commission makes tablets available to the states in amounts of 130 mg, which may in an emergency make it more difficult to achieve accurate dosage of small children. An FDA-approved 65-mg KI tablet with cross scoring is available. This enables the tablet to be quartered. One-quarter tablet is the dosage required for a young infant. It has been a challenge to provide with sufficient clarity the rather complex notion that the very young are very sensitive to the radioiodine exposure, that it is essential that they receive a sufficient dosage, and that it is important not to overdosage, because of risks to

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident normal growth and development. The additional message for full disclosure is that although taking KI will reduce the risk of thyroid disease, it will not protect against the radiation effects of other radioactive materials released with the radioactive iodine. States would clearly benefit from research to ensure that such messages are given in a manner that would lead to the desired outcome. Number of Tablets to Stockpile for Postdistribution. Some states merely stockpiled tablets that were not retrieved by the public in the predistribution. Other states set aside a specified number per person, and at least one purchased for post distribution tablets beyond those given by the Nuclear Regulatory Commission. Means and Circumstances of Advising the Public to Take KI. All states on which such information was available refer to the triggering dosage levels given in the FDA guidance. Some that have predistributed KI will advise the public to take KI at the same time that emergency workers in the EPZ are given word to ingest the tablets. If KI is to be provided at evacuation or reception centers, several states have information sheets for advising the public of adverse reactions and dosages. Some states will administer KI under the supervision of physicians and registered nurses. Others will have other public-health professionals available to answer questions. Distribution Postincident from Stockpiles to Reception Centers and Shelter in Place Locations. Issues to be considered include the number and placement of stockpiles with respect to where they will be needed in a nuclear incident. Restocking and Resupply. Few states have in place plans for resupply when official or actual shelf-life expires. The Nuclear Regulatory Commission has made no commitment to resupply states. If needed in the days after a major incident, resupply is dependent on the Strategic National Stockpile.

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident Conclusions In the United States and internationally, iodine blockade is supplemental to evacuation and sheltering in place, and this is appropriate. Because KI is most effective when taken within a few hours of exposure to radioiodine, predistribution programs are used extensively. Some states do not have distribution programs and rely on evacuation for protection. The committee did not review the relevant information to conclude whether, in the event of a serious incident, rapid and complete evacuation could be accomplished for sites without rapid access to KI, but it notes the need for such an evaluation. Local, rapid access to KI is accomplished through stockpiling and predistribution. Predistribution to residences alone is not sufficient to protect the public, and local stockpiling appears to be a part of all local KI distribution programs. Because of low coverage and inadequate education, some predistribution programs offer little more protection than a stockpiling program, although these ineffective programs do provide a “right to have” KI even though few decide to obtain it. Several states had predistribution programs that reached less than 10% of the affected population. Voluntary pickup programs reach more than 50% of the general population only if there is active community involvement. Door-to-door delivery appears more effective, but can be costly. With mass mailing, greater coverage can be obtained, especially when it does not involve completion of request forms. It may be, though, that fewer recipients of mass mailings will be able to retrieve stored KI in an emergency. The fraction of residents recalling where they have stored KI, say, 2-3 years after obtaining it and how this might be related to the method of distribution and public-information campaigns have not been adequately studied. Even with the most efficacious predistribution programs, well-developed programs for local stockpiling and postdistribution are required to ensure protection. The Nuclear Regulatory Commission offered KI coverage for those working and living within the 10-mile EPZ, and all local distribution programs in the United States are designed for this coverage. Geographic features and weather conditions vary

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident substantially among NPPs and alternative coverage areas might be preferable. These could be based on analyses to evaluate the populations that may be at significant risk from radiation exposures under different release scenarios and on the related contours to circumscribe the area associated with that risk. It would also aid in consideration of whether more-detailed planning of KI distribution to populations beyond the 10-mile EPZ is warranted. Furthermore, such analyses would provide the states and communities a framework for considering alternative intervention and significant risk levels. FDA recommends intervention with KI administration at 50 mGy (5 rad) exposure to children; at this level, FDA determined that radiation-induced cancers were not observed to be increased in the Chornobyl population. Using the WHO dose-response analysis, 50 mGy (5 rad) corresponds to a risk of five thyroid cancers per 10,000 children exposed. Some states may wish to afford a different level of risk protection to potentially exposed populations. FDA’s messages regarding advice on dosages are not uniform. The current guidelines, interpretive guidance, and approved labeling of KI differ, and considerably different messages have been developed by states to provide advice and procedures for KI administration. Precautions regarding overexposure of neonates and follow-up monitoring of the very young for hypothyroidism once KI is administered are not given by some states. Different messages are also given for populations that may be sensitive to iodine. A consistent set of advice from FDA regarding adequacy of messages to protect the public from the risks of overexposure but to encourage adequate dosage is needed. The difficulty of providing complicated messages to effect optimal behavior under emergency conditions is recognized. In this regard, research would benefit the states in the development of effective education and mass-media strategies and benefit FDA and the states in developing packaging and labeling messages. Several states’ distribution efforts were hampered by the limited support given for distribution programs by the Nuclear Regulatory Commission. Many states noted that they did not have sufficient funds for resupply and stockpile, which the commission has

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Distribution and Administration of Potassium Iodide in the Event of a Nuclear Incident not committed to support. For some states, decisions on whether to use KI and how to use it also appear to depend on federal funding.