PUBLIC HEALTH ASSESSMENT

PUBLIC HEALTH IMPLICATIONS OF RADIATION CONTAMINATION AT
FORMER CLOCK FACTORIES LOCATED IN
BRISTOL (HARTFORD COUNTY), NEW HAVEN (NEW HAVEN COUNTY), THOMASTON (LITCHFIELDCOUNTY), AND WATERBURY (NEW HAVEN COUNTY)
CONNECTICUT

DISCUSSION

Radiation Surveys

Radiation surveys included gamma, alpha, beta radiation, and radon gas sampling. The gammaradiation measurements included direct contact, and waist level or general area readings. The waistlevel readings are measured at three feet from the suspected source.

The alpha and beta radiation measurements were reported as either fixed or smearable. Thesmearable results indicate that radioactive contamination is present. The units of radiation aredependent on the radiation type and measurement techniques. Gamma radiation is generally reportedin uR/hr (micro Roentgen per hour). Alpha and beta radiation units are either reported as counts perminute (cpm) or disintegrations per minute (dpm). The value of dpm will always be greater than thevalue for counts per minute, since the efficiency for the alpha detector is approximately 30 percentand the beta/gamma detector is approximately 10 percent. Radon is a radioactive gas that is a decayproduct of radium. The units of measurement are pCi/L (pico Curie per liter).

The CT DEP requested radiological assistance from the US Department of Energy (DOE) on April1, 1998. Surveying was conducted from April 2, 1998, to April 7, 1998.

On April 2, 1998, the DOE/CT DEP team conducted sampling at the Waterbury Clock Companyincluding, the Ville Swiss Automatics and Belco.

On April 3, 1998, the investigation proceeded to the former Lux Clock Company in Waterbury.

On April 6, 1998, the radiation survey investigated the former Seth Thomas Clock company inThomaston, as well as the former Benrus Clock Company in Waterbury.

On April 7, 1998, the Thomaston radiation survey was completed, and a separate survey wasconducted in New Haven.

The results of the radiation surveys are presented below in Tables 2 through 14. Each table identifiesthe town name, former clock company name, current occupant, location of sample, maximumradiation levels detected, background levels, and the relevant comparison value. In 1997, EPA issuedOSWER Directive 9200.4-18, Establishment of cleanup levels for Superfund sites with radioactivecontamination. This directive provides guidance for establishing protective cleanup levels forradioactive contamination at Superfund sites. Using this directive, an effective dose of 15 mRem/yrequates to an increased lifetime risk of 3 in 10,000 of cancer, serving as the upper bounds of EPAacceptable risk. This would include exposures from all pathways, and through all media (e.g., soil,ground water, surface water, sediment, air, structures, biota).

Results of Radiation Surveys

Occupant(s): DABKO CO.

CL = EPA Cleanup Level
NR = not reported
uR/hr = Micro Roentgen per hour

CL = EPA Cleanup Level
uR/hr = Micro Roentgen per hour

CL = EPA Cleanup Level
uR/hr = Micro Roentgen per hour

CL = EPA Cleanup Level
cpm = counts per minute
dpm = disintegrations per minute
NR = not reported, background counting rates ranged from 0.2-0.3 cpm for alpha, and 30-50 cpm for beta/gamma.
uR/hr = Micro Roentgen per hour
*The cpm units can be converted into dpm units, however the calibration isotope is required for this. In general, if an unconverted cpm value exceeds the dpm cleanup level, then the converted value will also be greater.

CL = EPA Cleanup Level
NR = not reported
pCi/L = Pico Curries per Liter
uR/hr = Micro Roentgen per hour

CL = EPA Cleanup Level
dpm = disintegrations per minute
NR= not reported, background counting rates ranged from 0.2-0.3 cpm for alpha, and 30-50 cpm for beta/gamma.
uR/hr = Micro Roentgen per hour

<MDA = less than minimum detected activity
CL = EPA Cleanup Level
dpm = disintegrations per minute
NR = not reported, background counting rates ranged from 0.2-0.3 cpm for alpha, and 30-50 cpm for beta/gamma.
uR/hr = Micro Roentgen per hour

CL = EPA Cleanup Level
dpm = disintegrations per minute
NR = not reported, background counting rates ranged from 0.2-0.3 cpm for alpha, and 30-50 cpm for beta/gamma.
uR/hr = Micro Roentgen per hour

CL = EPA Cleanup Level
dpm = disintegrations per minute
NR = not reported, background counting rates ranged from 0.2-0.3 cpm for alpha, and 30-50 cpm for beta/gamma.
pCi/L = Pico Curries per Liter
uR/hr = Micro Roentgen per hour

CL = EPA Cleanup Level
dpm = disintegrations per minute
NR = not reported, background counting rates ranged from 0.2-0.3 cpm for alpha, and 30-50 cpm for beta/gamma.
uR/hr = Micro Roentgen per hour

CL = EPA Cleanup Level
NR = not reported
pCi/L = Pico Curries per Liter
uR/hr = Micro Roentgen per hour

CL = EPA Cleanup Level
NR = not reported
pCi/L = Pico Curries per Liter
uR/hr = Micro Roentgen per hour

CL = EPA Cleanup Level
Nd = none detected
pCi/L = Pico Curries per Liter
uR/hr = Micro Roentgen per hour

Radium Toxicity

Studies have shown that internal deposition of ²²⁶Ra results in the induction of skeletal tumors andparanasal sinus carcinomas (cancer of the sinus cavities) (3, 4). Argonne National Laboratory andits' Center for Human Radiobiology have studied the human health effects of radium deposition forover 20 years. Stebbings, et al. (5) reported that in U.S. white females employed as dial painters, therates of liver, pancreatic, cervical, and uterine cancers were not related to radium exposure. Somecancers of the digestive system, however, may have been indirectly related to radium exposure. Theyreported that although, there was an increase in multiple myeloma (a form of leukemia), indicationswere that this increase was related more to the length of employment as a dial painter than the amountof radium in the body. This indirectly suggests the myeloma may be due to the external exposure tothe gamma radiation emitted during the radioactive decay of ²²⁶Ra.

The major health effects resulting from internally deposited ²²⁶Ra are noted in cases dealing withoccupational exposure, the majority being radium dial painters. The alpha particle is the major typeof damaging radiation from internalized (inhaled or ingested) ²²⁶Ra. This decay particle travels veryshort distances within the body and the majority, if not all its energy is absorbed within the body partwhere the ²²⁶Ra is deposited. ²²⁶Ra has chemical characteristics similar to calcium therefore, most ofthe ingested ²²⁶Ra deposits in bones where the greatest exposure and dose is delivered to bonesurfaces and perhaps the blood-forming bone marrow. Additionally, more specific informationregarding ²²⁶Ra is given in Appendix A.

As of 1984, almost 6,000 individuals with all types of exposure to radium had been locatedthroughout the United States (6). Of the 6,000 identified, 1,907 dial painters were located and hadtheir radium body burden measured. In this group, there were 44 cases of bone tumors and 19 casesof sinus or mastoid (associated with the head) carcinomas. These totals include three individuals withboth types of illnesses. The study concluded that these illnesses and skeletal tissue deterioration werenevertheless unquestionably related to the presence of internal radium.

Radiation doses and related information: International and National

The National Council on Radiation Protection and Measurements (NCRP) is a non-governmentalbody that makes recommendations to the radiation protection community within the United States. In 1987, the NCRP recommended that in the case of continuous or frequent exposure to radiation,a population should not exceed 1 milliSieverts (mSv; 100 milliRem per year [mRem/yr]) abovebackground. For a population infrequently exposed, a limit of 5 mSv (500 mRem/yr) wasrecommended (7). In 1994, the NCRP reaffirmed and refined these exposure limits (8).

Smear Samples

The radiation protection industry has adopted stringent, acceptable levels of surface contaminationthat is fixed in place (non-removable) or that which can be removed from the contaminated surface. In the case of removable contamination, these levels are determined by taking a surface smear froma square meter area and averaging the results per 100 square centimeters (cm²). The radioactivematerial collected by this procedure is analyzed for the specific radionuclide. For non-removable²²⁶Ra, the average allowable limit is 100 dpm per 100 cm², and the maximum allowable limit in any100 cm² area is 300 dpm. If more than 20 dpm can be removed, then the contaminated surfaceexceeds these federal standards (9).

The US Environmental Protection Agency (EPA) uses Applicable or Relevant and AppropriateRequirements (ARAR) which, in many cases, serve as the determining factor for site cleanup. Because the contamination in these non-Superfund facilities are not specifically addressed by ARARvalues, the EPA can set site specific cleanup levels. In 1997 EPA issued OSWER Directive 9200.4-18. Establishment of cleanup levels for Superfund sites with radioactive contamination (10). Thisdirective provides guidance for establishing protective cleanup levels for radioactive contaminationat superfund sites. Using this directive, an effective dose of 0.15 milliSieverts (mSv; 15 mRem/yr)equates to an increased lifetime cancer risk of 3 in 10,000, serving as the upper bounds of EPAacceptable risk.

Discussion of removable contamination

Removable contamination indicates how easily radiologic contamination might be transferred tohumans or other surfaces. This is performed by using a standard size paper swab and gently butfirmly rubbing the paper over an area of 100 square centimeters. The paper is then checked for typeof radioactivity removed and the results are expressed as disintegrations per minute (dpm) per 100square centimeters (cm²) of surface. Surface contamination limits have been established for ²²⁶Ra (9);the limit for removable ²²⁶Ra contamination is 20 dpm/100 cm².

Discussion of Results

The following section summarizes the results presented in the tables above. This section describesthe results stratified by town and presents an overview of the radiation surveys conducted thus far. Locations that have not been fully characterized (identified previously pending data) are alsodiscussed.

Bristol:

All facilities in the Sessions Clock Company were examined. Radiation was detected in two locations above the EPA risk-based cleanup level in two buildings. The locations included: a storage area on the 4th floor of building A, the other was located in an area designated as an old storage area on the 3rd floor of building D. These areas are not currently occupied. One area of the first floor of the Bristol Instrument Gears building was affected with radiation levels at the EPA risk-based cleanup level.

 

New Haven:

Club International is the current occupant of the four story building associated with the former New Haven Clock Company buildings. The first two floors are not affected, the third and fourth floors are pending further investigations.

 

Goodies Repairs is the current occupant of the two story building associated with the former New Haven Clock Company buildings. The first floor has one small spot identified as containing radiation levels above the EPA risk-based cleanup level. The second floor is pending further investigations.

 

St. John's Restaurant is the current occupant of the second four story building associated with the former New Haven Clock Company buildings. The first floor is not affected. The second through fourth floors are pending further investigations. There are several abandoned building also associated with the former New Haven Clock Company. These structures range in size from four to six floors. These have not been fully characterized and are pending further investigations.

 

Thomaston:

The Former Seth Thomas Clock Company was affected with radiation in isolated areas on the first through the fourth floors. Two companies located in the basement and a social club on the fourth floor are pending further investigations. The basement of this structure contains two areas not characterized and one identified as unaffected. The first floor was only affected in one facility, the Verka Enterprise. The second floor was affected in two locations which include the Gaynor Electric facility and WTM. The affected locations on the third floor included the Power Trans facility, the Global Spice Company, and J. McGowan facility. The fourth floor location identified as containing radiation levels above the EPA risk-based cleanup level is the storage area.

Waterbury-Benrus Clock Company:

Radiation levels were above the EPA risk-based cleanup level in isolated areas of the fourth, fifth, and seventh floors of the former Benrus Clock Company building. The current occupant is Bender Plumbing.

Waterbury-Lux Clock Company:

Radiation levels were above the EPA risk-based cleanup level in isolated areas of the first through the fourth floors of the former Lux Clock Company building. The current occupant is Anchor Advanced Products, which is also known as Lakewood Metals.

Waterbury-Waterbury Clock Company:

The affected areas of the former Waterbury Clock facility currently occupied by the Belco company include the cutting room and machine shop in the second floor; the store room, hallway, and Liba section of the third floor, the store room on the fourth floor, and the rental area of the fifth floor. The highest detected levels of radiation above the EPA risk-based cleanup level were located on the third floor hallway. This section is not frequently used. The radiation source has been covered with tape. The tape was used to prevent loose material from being relocated by accidental contact. This procedure will not, however, reduce gamma radiation levels emitted from that location.

 

Many of the areas within the Belco facility were checked for removable contamination using the procedure discussed in the previous section. The results indicated that in all areas checked, the removable contamination was positively identified as ²²⁶Ra, and exceeded the regulations. These areas included: 1) the second floor machine shop 2) the third floor store room, hallway, and Liba 3) the fourth floor store room and 4) the fifth floor rental areas. In these areas, the removable alpha contamination ranged from approximately 20 dpm/100 cm² to over 7,900 dpm/100 cm². These areas contained beta/gamma removable contamination at levels ranging from approximately 200 dpm/100 cm² to over 16,600 dpm/100 cm². Because there is insufficient information as to the amount of dust loading in these areas, additional dose assessment is not possible at this time

 

The occupant of a second Former Waterbury Clock facility is the New Opportunities for Waterbury (NOW). This structure has thirteen offices identified as containing radiation levels above the EPA risk-based cleanup level. The third floor contains one of these offices, the fourth floor houses eight, and the fifth floor has four of these offices.

 

The five story building associated with the former Waterbury Clock Company which houses Ville Swiss Automatics Automotive is affected on isolated areas of the third through fifth floors.

 

Enterprise Apartments is located in another structure also associated with the former Waterbury Clock Company. This complex has radiation levels above the EPA risk-based cleanup level in isolated areas of one fourth floor apartment and in isolated areas of nine 5th floor apartments. Additionally a section of the fifth floor hallway is affected. Two additional apartments on the fifth floor contained radiation levels slightly below the EPA risk-based clean up levels at waist level, but exceeded this value with direct contact readings.

Pathway Analysis

To determine whether occupants, workers, or visitors have been or are being exposed to radiation,the CT DPH and the ATSDR evaluate the environmental and human exposure and an exposedpopulation. There are three types of exposures when radium is present:
- gamma ray exposure occurs when people are near the radium;
- radon exposure, occurs when radium decays into radon and is inhaled (breathed); and
- radium dust exposure occurs through inhalation, dermal contact (direct contact with the skin), andingestion (through the mouth) of dust.

The pathways analysis consist of: the source of contamination, a point of exposure, a route ofexposure, and an exposed population. The ATSDR categorizes exposure pathways as eithercompleted or potential pathways. For an exposure pathway to be completed all elements of thepathway must be present. Potential pathways are those where there is not sufficient evidence to showthat all the elements are present now, could be present in the future, or were present in the past.

Completed exposures have occurred to gamma ray and radon exposure to radium and radon. Thereis insufficient information to determine whether dust containing radium is present in the air of theaffected buildings. In addition, there is insufficient information regarding current or past exposuresto dust on any surface in the affected buildings. Consequently, the exposure pathway involving dustis considered potential.

Public Health Implications
Occupants of buildings identified with radium radiation levels above 15 mRem/yr may be at a lowincreased risk of developing bone cancer. This risk may be characterized as higher at locations wherethe radiation source has been identified as moveable (smearable). These locations may be exposingoccupants to an additional health risk due to inhalation and incidental ingestion of radium-contaminated dust particles. Additionally, elevated levels of radon gas were detected in the 4th floorof the Waterbury Clock Company building which now houses Belco. This concentration of radongas may increase the risk of developing lung cancer among occupants of that facility. The source ofthe radon gas is from the radiation decay products of ²²⁶Ra.

Conclusions

1. The former Waterbury Clock factory buildings are contaminated in isolated areas with radioactive material emitting radiation at levels (as measured at waist level) that may pose a public health hazard to occupants of the buildings.
2. The former Sessions Clock Company in Bristol (in isolated areas of the fourth floor of building A and in isolated areas of the third floor of building D) are contaminated with elevated levels of radiation. The CT DPH understands that the locations where the radiation was detected is not currently occupied. However, if the use of these locations changes, occupants may be exposed to radiation at levels of a public health hazard. The Bristol Instrument Gears Company has radiation levels at the EPA risk-based cleanup level.
3. The former Seth Thomas Clock Company in Thomaston (in isolated areas of the first through the fourth floors) are contaminated with elevated levels of radioactive material. The occupants may be exposed to radiation at levels considered a public health hazard.
4. Many of the areas within the Belco facility were checked for removable contamination, and the results indicated that sections of each floor were contaminated with removable ²²⁶Ra which exceeded the regulations. These areas included: 1) the second floor machine shop 2) the third floor store room, hallway, and Liba 3) the fourth floor store room and 4) the fifth floor rental areas.
5. Two sites, included as part of these radiation scoping surveys, have data gaps in New Haven and Thomaston. Specifically, the data gaps for the New Haven site include the third and fourth floors of the building which houses Club International, as well as the second through fourth floors of the building which currently houses St. John's Restaurant. The data gaps for the Thomaston site include two areas located in the basement, and a social club located on the fourth floor.
6. Locations that have been adequately characterized and do not contain radiation levels abovebackground, represent no public health hazard to the occupants.

1. Dissociate people from areas contaminated with radiation at levels exceeding the EPA directivefor establishing protective cleanup levels for radioactive contamination (15 mRem/yr). Thefollowing table lists the locations of elevated radiation levels:

* Only isolated areas of the floors listed were affected.
** These apartments were slightly below the EPA risk-based cleanup levels at waist level, but exceeded this value on direct contact.

2. Mark all areas identified as containing radioactive contamination exceeding the EPA cleanup level of 15 mRem/yr.
3. Complete full radiation characterization surveys of all sites. Specifically, the following locations are pending further investigations in the New Haven Clock Company buildings: the third and fourth floors of the Club International Building, the second floor of the Goodies Repairs building, the second through the fourth floors of the building which houses St. John's Restaurant, and the multiple abandoned buildings. Additionally, the former Seth Thomas Clock Company in Thomaston has areas in the basement, and on the fourth floor that are pending further investigations.
4. ATSDR and the Connecticut Department of Public Health recommend that the amount of radioactive dust on the floors and in the air be determined in order to assess the radiologic inhalation and ingestion doses from ²²⁶Ra.
5. Inform occupants of all buildings of the findings of this Public Health Assessment.
6. Radon sampling should be conducted to further characterize sites.

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