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This public health assessment was developed 1) to evaluate the radiation data collected by theConnecticut Department of Environmental Protection (CT DEP) at structures that once housed clockfactories in four Connecticut municipalities, and 2) to determine whether a public health hazard existsat any of these sites from the contamination.

Contamination was detected at levels that may pose a health risk to current occupants at the formerWaterbury Clock Factory, the former Lux Clock Factory, and the former Benrus Clock Companybuildings in Waterbury; the former Sessions Clock Company in Bristol; and the former Seth ThomasClock Company in Thomaston. However, none of the radiation levels detected pose an immediatehealth problem. Many areas of the Belco facility (located in one of the former Waterbury ClockFactory buildings) had removable contamination that exceeded the Radium-226 (226Ra) regulations. Additional radiation surveys are needed to establish the degree of contamination in the New Havenand Thomaston locations. In other locations that were adequately characterized as described in thispublic health assessment, radiation levels did not exceed background and do not pose a health risk.

The Connecticut Department of Public Health recommends that individuals be disassociated fromareas with radiation at levels exceeding 15 mRem/year. Further investigations should be conductedto characterize the extent of contamination in other structures. The amount of dust on the floors andin air in contaminated structures needs to be determined in order to assess the radiologic inhalationand ingestion exposures to 226Ra. Radon sampling should be considered to further characterize thesesites. The findings of this Public Health Assessment should be provided to all occupants of thesurveyed structures.

The CT DPH will continue to provide environmental health education for local public health officials,the local medical community and local citizens to assist the community in assessing possible adversehealth outcomes associated with exposures to toxic substances. The CT DPH will reviewremediation plans to ensure the continued protection of public health during all phases of site cleanup.

The conclusions and recommendations in this Public Health Assessment are based on the data andinformation made available to the Connecticut Department of Public Health and the Agency forToxic Substances and Disease Registry. The Connecticut Department of Public Health and theAgency for Toxic Substances and Disease Registry will incorporate additional information if andwhen it becomes available. The incorporation of additional data could change the conclusions andrecommendations listed in this document.


There are four towns in Connecticut that have historic data indicating clock factories were locatedin these municipalities. These include: Bristol, New Haven, Thomaston, and Waterbury. On June12, 1998, the U.S. Environmental Protection Agency (EPA) requested (1) that the Agency for ToxicSubstances and Disease Registry (ATSDR) examine the radiation data available for the former clockfactories located in four towns. The purpose of this Public Health Assessment is to evaluate theradiation data provided by the Connecticut Department of Environmental Protection (CT DEP) (2), determine whether a public health hazard exists at any of these site, and to recommend appropriatepublic health actions to minimize known exposures.


Radium-226 (226Ra) has a half life of 1,600 years. It was used from the beginning of this centurythrough the 1940's to paint number dials on clocks, watches and aircraft navigation equipmentbecause of the paint's ability to illuminate in the dark. Earlier this year a researcher at the Universityof Illinois was investigating the distribution of radium dial painters throughout the country. Duringthis investigation, the CT DEP was informed of former radium dial painting facilities at the WaterburyClock Company. Other former radium dial painting sites have been identified outside the City ofWaterbury in Bristol, New Haven, and Thomaston. They are described below.

Two clock manufacturing facilities were located in the City of Bristol: the Ingram Clock Companyand the Sessions Clock Company.

- In 1914, the Ingram Company began making pocket watches, and in 1930, started producingwrist watches. The factory complex was torn down in the late 1960's. Since this complex was torndown, no radiation surveys have been conducted to date.

- In 1903, the Sessions Clock Company began operation and produced mantle and kitchen clocks. In 1958, the company was sold and the new company continued to produce clocks until 1968. In1960, one of the buildings was sold to he Bristol Instrument Gears Company. In 1970, theremaining buildings were sold to Dabko Industries, a machine parts manufacturer. The followingcompanies are housed in the Sessions Clock Company buildings: Bristol Instrument Gears, DabkoCO., NuTECH, CT Graphics, and C&R Printing. Radiation surveys were conducted in each ofthese companies.

New Haven
One clock manufacturing facility was located in the City of New Haven: the New Haven Clock Company.

-In 1853, the New Haven Clock Company was incorporated as a supplier of brass clockmovements. This facility produced many types of clocks including pocket versions (started in1880), and wrist watches (started in 1917). This facility produced over 40 million watches between1880 and 1959. This complex consists of several buildings. The building occupants now include:Club International, Goodies Repairs, and St. John's Restaurant. Most of the total building spaceis unoccupied or abandoned. Club International is housed in the first two floors of the four storybuilding. There is little information about the third and fourth floors of that building. Access hasnot been allowed for survey purposes in all of the buildings. Goodies Repairs is located in the firstfloor of the two story building. St. John's Restaurant is located in the first floor of the four storybuilding. There have not been any radiation surveys conducted at the abandoned buildings.

One clock manufacturing facility was located in the City of Thomaston: the Seth Thomas Clock Company.

- The Seth Thomas Clock Company produced pocket watches from 1882 until 1915. During thisperiod over four million watches were made. The facility was damaged in 1955 by flooding. Thebuilding is a four story structure that is being rented out to twenty different companies. Radiationsurveys have been conducted on each floor. Sections of the basement and fourth floor were notcompletely characterized.

Three clock manufacturing facilities were located in Waterbury: the Waterbury Clock Company,the Lux Clock Company, and the Benrus Clock Company. Radiation surveys have been conductedin these former clock company facilities.

- From 1857 through 1944, the Waterbury Clock Company produced clocks. Inexpensivewatches were produced starting in 1880. In 1919, radium dial painting was started at theWaterbury Clock Company. There are numerous reports of occupational diseases and possibleradiation related deaths from these early days of operation of the Waterbury Clock Factory. Thisfacility now houses a leather clothier, an apartment complex, and a human service center forWaterbury.

- The Lux Manufacturing Company, formerly known as the Lux Clock Company, beganmanufacturing in 1914. This facility now houses Anchor Advanced Products.

- The Benrus Clock Company historically produced watches and now is occupied by Benderplumbing.

Table 1. lists each town in which there were reports of radium use at clock companies. The table liststhe town name, the original clock company name, the current building occupant(s), and whether thebuildings have detectable levels of radiation. Three terms are used to describe the results for eachlocation: affected, pending, and not affected. Locations defined as "affected" have detectable levelsof radiation above background levels, but not necessarily at levels of health concern. The term"pending" is used to indicate locations that have not been fully characterized. Locations with noradiation levels above background are defined as "not affected".

Table 1.

Former Clock Manufacturing Facilities in Connecticut
Town Clock Factory Name Current Occupant Results
Bristol Ingram Clock Company None- Building was torn down in 1960s not applicable
Sessions Clock Company Dabko Industries
CT Graphics
C & R Printing
Bristol Instrument Gears
Not affected
Not affected
Not affected
New Haven New Haven Clock Company Club International
Goodies Repairs
St. John's Restaurant
Abandoned buildings
Not affected
Not affected
Thomaston Seth Thomas Clock Basement - Global Ball Mfg.
Basement - Power Trans
Basement - Quality Rolling

Not affected
First Floor - A.S.A.P.
First Floor - Cesco Brass
First Floor - CD Proctor
First Floor - Diane's Dance
First Floor - Feel Good Fitness
First Floor - J-Conn
First Floor - Vereka Enterprises
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
Second Floor - Gaynor Electric
Second Floor - National Spring
Second Floor - W.T.M.
Not affected
Third Floor - Conn Outreach
Third Floor - ECI
Third Floor - Global Spices
Third Floor - J. McGowan
Third Floor - Sort of Unique
Third Floor - Rob Whelan
Third Floor - Power Trans
Not affected
Not affected
Not affected
Not affected
Fourth Floor - Italian Club
Fourth Floor - Storage
Fourth Floor - Workshop Area
Fourth Floor - Church
Not affected
Not affected
Waterbury Waterbury Clock Company Belco
Villa Automatics
Enterprise Apartments
New Opportunities for Waterbury (NOW)
Lux Clock Company First floor -Anchor Advanced Products
Second floor -Anchor Advanced Products
Third floor -Anchor Advanced Products
Fourth floor -Anchor Advanced Products
Benrus Clock Company First floor - Bender Plumbing
Second floor - Bender Plumbing
Third floor - Bender Plumbing
Fourth floor - Bender Plumbing
Fifth floor - Bender Plumbing
Sixth floor - Bender Plumbing
Seventh floor - Bender Plumbing
Not affected
Not affected
Not affected
Not affected

The estimated population potentially exposed to the radium contamination is isolated to theoccupants, workers, and visitors of the former clock factories. The population estimates for theformer radium sites in each town for occupants (including children), workers, and visitors are asfollows: Bristol: 50, New Haven: 15; Thomaston: 150, and Waterbury: 300 (including about 10 children).

ATSDR Child Health Initiative
Infants and children are more sensitive to environmental exposures than adults in communities withcontaminated water, soil, air, or food, since 1) children play outside and are likely to be more exposedto soil or surface water, 2) children are shorter and closer to dust, soil and vapors near the ground,and 3) children have a higher metabolic rate than adults, resulting in a higher dose per body weight. Since exposures to children may affect development and growth, the CT DPH and the ATSDR arecommitted to evaluating potential exposures to children as part of the Child Health Initiative. Thechildren likely to be exposed to this contamination are the approximately 10 children that live in theEnterprise Apartment Complex, and any child visitors to the NOW building. The children in theapartment complex may have been exposed for as long as 10 years. Children visiting the NOWbuilding may have been exposed for a shorter period of time. However, both of these exposures donot represent an immediate health concern.

Health Outcome Data
The results of radiation surveys indicated that isolated areas contained elevated levels of radiation,however, no current exposures were occurring that represented an immediate public health concern. Continuous exposures for durations of 30 to 70 years represent a possible increased risk ofdeveloping some types of cancer. Because the number of people exposed is small, and the durationof continuous exposure is unlikely to be 30 to 70 years, an evaluation of available health outcome data is not warranted.

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