BELL GARDENS — Employees at two schools next to chrome-plating plants have not had a significantly higher rate of miscarriages than normal, as had been feared, according to a preliminary report on a county health survey.
A draft report released this week by the county Department of Health Services said the eight miscarriages reported by employees at Suva elementary and intermediate schools since the beginning of 1986 is not an excessively high number, but it recommended that the miscarriage rate be tracked for another two or three years.
The two plants--Chrome Crankshaft Co. and J & S Chrome Plating Co.--emit hexavalent chromium, a toxic metal that causes cancer in people and has triggered miscarriages and birth defects in laboratory animals exposed to high doses. Hexavalent chromium has not been shown to cause miscarriages and birth defects in humans, said Dr. Paul Papanek, chief of the county's toxics epidemiology program.
The survey found that 12% of the 66 pregnancies among employees at the schools from 1982 to last April ended in miscarriages but that in 1987 alone, 29% of pregnancies ended in miscarriages.
More than 250 staff members--92% of the total at the two schools--completed questionnaires.
No miscarriages were reported from 1982 to 1985, one was reported in 1986, five in 1987 and two this year, according to the report.
The overall rate "falls within the expected, or background, rates of 10% to 20%," the report said.
The report said the five miscarriages out of 17 pregnancies in 1987--the 29% rate--is of "borderline statistical significance."
"This represents two to three excess cases, which can be expected to occur by chance alone in a study population of this size," it said.
Three of the eight miscarriages involved deformed fetuses, but no birth defects were reported in babies born to school employees since 1982.
"It appears that the rate and pattern of fetal malformations (in miscarriages) . . . is about what would be expected," the report said.
Roberta Swanson, an eighth-grade teacher at Suva Intermediate School and spokeswoman for concerned school employees, said the report did not eliminate their worries.
"We're concerned because of the apparent rise . . . in the past two years," she said. "We feel there needs to be continuing monitoring. For the women who want to start families, they need to know."
In addition, Swanson said, an unofficial staff survey revealed two miscarriages that were not included in the county's total. Such differences will be reconciled before the final survey report, Papanek said.
Swanson said she also is concerned about an elevated rate of ectopic, or tubal, pregnancies. Since 1982, employees at the two schools have had five tubal pregnancies, an 8% rate, compared to a rate of 1.4% among all reported pregnancies in the United States in 1983.
But here, too, the report said that because of the small number of people being surveyed, the higher rate is not statistically significant.
The survey also asked school employees to report cancer cases, respiratory problems and symptoms of irritation, such as sore throats, red eyes and nausea. Epidemiologist analyst Carolyn Ward said an analysis of those areas is pending.
Meanwhile, a health survey of the residential community surrounding the schools has been completed and was submitted this week to Papanek for analysis. School employees surveyed more than 2,400 people in 584 households, Swanson said.
Swanson said the survey appeared to find elevated cancer and miscarriage rates, and low birth rates, in some neighborhoods surrounding the plants. But the results must be reviewed and verified before any conclusions can be drawn, Papanek said.
"It's important for us to keep looking," he said.
Suva Elementary was built in 1938, and Suva Intermediate began conducting classes in 1959. The two chrome-plating plants have been in operation since the late 1950s and early 1960s.
Air tests conducted at and around the schools earlier this year detected unacceptably high levels of hexavalent chromium, the South Coast Air Quality Management District reported.
The light industrial area just east of the schools is the most affected. An estimated 630 to 7,700 additional cancer cases per million people would occur in that area, based on 24-hour-a-day exposure over 70 years, the AQMD report said.
The risk is lower for school employees, who are exposed only part of the day in an area with lower concentrations of the toxic metal. Partial exposure to the average concentration of hexavalent chromium detected at the schools would produce an 37 to 450 additional cancer cases per million people, the AQMD said.
Hexavalent chromium from industrial plants is present in small amounts in air throughout the Los Angeles Basin.