SKILLED CRAFTS such as jewelry making are practiced in many Native American communities in the United States. Jewelry making is culturally and economically vital for the Zuni tribe, whose work is known for its intricate designs. Inefficient exposure controls in home-based workshops may result in contamination of the home with byproducts from the jewelry-making process. The extent of metal exposures among home-based jewelers is essentially unknown.
Jewelry making is a potential source of exposure to heavy metals such as lead and cadmium, which are nephrotoxic. (1,2) Among the Zuni, the prevalence of end-stage renal disease is 6 times higher than in other Native American tribes and 20 times higher than in European American populations. (3) The severity and prevalence of renal disease in this population exceeds that expected from known risk factors such as diabetes. To date, no surveys have been conducted to evaluate the extent of environmental exposures, such as those arising from making jewelry, that may contribute to renal disease in this population.
The objectives of this pilot study were (a) to inventory the materials, personal protective equipment, and ventilation measures used by Zuni jewelers in their homes; and (b) to determine whether surface concentrations of metals are higher in jewelry-making households than in households in which no jewelry is made. The effectiveness of ventilation controls for reducing work and living area surface metal concentrations in jewelry-making homes was also evaluated. This study was performed to fill a gap in the existing knowledge regarding the extent of exposure to heavy metals and other potentially hazardous materials among Zuni jewelry makers. The authors hope that the results will aid in the formulation of targeted exposure questions and the selection of monitoring techniques for use in future population studies.
Method
Subjects. Participants were recruited from a previously assembled cohort of 1,500 Zuni tribal members who lived on the Zuni reservation in western New Mexico. (3,4) On the basis of data collected previously from adult ([greater than or equal to] 18 yr of age) cohort members regarding jewelry making, these individuals were stratified into 2 groups by household. If any household member reported making jewelry, all members of that household were included in the jewelry-making group. Otherwise, family members were classified in the non-jewelry-making control group. Twenty subjects were recruited from each group, one subject per household. The study protocol and informed consent forms were approved by the University of New Mexico Human Research Review Committee, Indian Health Services Institutional Review Board, and the Zuni Tribal Council. Subjects were recruited, and informed consent was obtained, by trained bilingual interviewers who were fluent in both English and the Zuni language (Shiwi). Informed consent was obtained from each participant after the nature of the survey had been fully explained.
Exposure survey. We developed a survey instrument to inventory the chemicals, metals, stones, and other materials used to make jewelry. Questions were also asked about the type and frequency of use of personal protective equipment and ventilation while working. The survey was developed with collaboration from Zuni tribal members who were part of the University of New Mexico field staff for the current study. It was designed to be sensitive to the tribal culture and beliefs and written in lay terms that would be understandable to the study population. A standardized oral translation of the survey was used to interview subjects who preferred Shiwi. Material safety data sheets were obtained from manufacturers or suppliers for each product reported in the survey, and product content and health hazard and safety information was extracted and summarized in a report for the participants.
All 20 jewelers interviewed (5 men and 15 women; mean age [+ or -] standard deviation = 43.2 [+ or -] 10.7 yr; average time making jewelry [+ or -] standard deviation = 22.1 [+ or -] 10.9 yr) reported making jewelry inside their homes. Of the 20 non-jewelry-makers interviewed (6 men and 14 women; mean age [+ or -] standard deviation = 43.8 [+ or -] 12.9 yr), 2 reported living in homes where another member of the household made jewelry, but that other person was not a member of the initial study cohort. These 2 households were subsequently reclassified as jewelry-making homes in the surface metal analyses.
Surface dust samples. The surface dust samples were collected and handled in accordance with standardized protocols. (5,6) A template was placed over the wall and floor areas closest either to the workbench (for work samples) or the dining room table (for living-area samples). A diagonal area of the template was then wiped with Whatman 41 70-mm filter paper (Whatman, Inc., Florham Park, New Jersey). A total of 715 [cm.sup.2] surface area was wiped at each location. Twenty-six wipe samples were collected from work areas and 22 from living areas of the 20 jewelry-making homes. Twenty-three samples were collected from living areas of the 20 control homes. Eighteen percent of the samples collected were duplicates obtained by wiping the opposite diagonal of the same template area. All surface wipe samples were analyzed for silver, copper, tin, mercury, nickel, zinc, lead, antimony, cadmium, and boron (a metalloid) by a single analytical laboratory using inductively coupled plasma mass spectrometry and graphite furnace atomic absorption spectrometry. (7,8)