Remy Linda L, Byers Vera, Clay Ted
Family Health Outcomes Project, Family and Community Medicine, School of Medicine, University of California San Francisco, 500 Parnassus Ave. Room MU-337, San Francisco, CA, 94143-0900, USA.
Immunology Inc, PO Box 4703, Incline Village, NV, 89450, USA.
Environ Health. 2017 Mar 6;16(1):18. doi: 10.1186/s12940-017-0222-8.
From 1963-1995, a factory in Willits, Mendocino County, CA used toxic hexavalent chromium (Cr(VI)) without adequate measures to protect the population. We use longitudinal hospital data to compare reproductive outcomes for two generations in Willits and two generations in the Rest of County (ROC). This is the first study to quantify the reproductive impact of Cr(VI) in a non-occupational population.
We searched California hospital discharge data (1983-2014) to find Mendocino County residents born 1950 or later. ZIP-code 95490 identifies Willits residents, with all others living in ROC. We used the Multi-Level Clinical Classification Software (CCS) to classify health outcomes. First, we calculated the crude birth rate using an external census denominator. The next two models used self-contained denominators to assess health of infants and two generations of pregnant women. Finally, we focused on non-pregnant females and, for comparison, males. Here we added admissions for people who moved, linked and summarized admissions to the person level, and calculated rates per census population.
We found 29311 newborn records in ROC and 5036 from Willits. At start of period, Willits birth rate was low and did not recover until 12 years after Plant closure. While the Plant was open, respiratory conditions, perinatal jaundice, and birth defect rates were higher for Willits infants compared to ROC, but improved post-closure. Risk for abnormal birthweight and term was high and remained high over the study period. During the period under study, we identified 31444 admissions of pregnant ROC women and 5558 from Willits. Willits women had significantly higher risk of pregnancy loss compared to ROC, whether stratified by generation, age group, or pre- and post-closure. Regardless of when exposed, Willits women continued to have significantly higher rates of in-hospital terminations, as animal studies of Cr(VI) exposure predict. In life course models, non-pregnant Willits women have significantly higher risk of reproductive organ conditions and neoplasms compared to ROC.
Adverse reproductive outcomes are elevated and consistent with animal studies. General health outcomes reflect the same broad effect reported for occupationally exposed workers. For the first time, the detrimental reproductive effects of non-occupational Cr(VI) exposure in human females and their infants is reported.
1963年至1995年期间，加利福尼亚州门多西诺县威利茨的一家工厂使用有毒的六价铬（Cr(VI)），却未采取足够措施保护居民。我们利用纵向医院数据，比较了威利茨两代人和该县其他地区（ROC）两代人的生殖结局。这是第一项量化非职业人群中Cr(VI)对生殖影响的研究。
我们检索了加利福尼亚州医院出院数据（1983年至2014年），以查找1950年或之后出生的门多西诺县居民。邮政编码95490可识别威利茨居民，其他所有人居住在ROC。我们使用多级临床分类软件（CCS）对健康结局进行分类。首先，我们使用外部人口普查分母计算粗出生率。接下来的两个模型使用自包含分母来评估婴儿和两代孕妇的健康状况。最后，我们关注非孕妇女性，并为作比较关注男性。在此，我们添加了迁入者的入院记录，将入院记录链接并汇总到个人层面，并计算每人口普查人口的发生率。
我们在ROC中发现了29311条新生儿记录，在威利茨发现了5036条。在研究期开始时，威利茨的出生率较低，直到工厂关闭12年后才恢复。工厂运营期间，威利茨婴儿的呼吸道疾病、围产期黄疸和出生缺陷率高于ROC，但在工厂关闭后有所改善。出生体重异常和足月出生的风险较高，且在研究期间一直居高不下。在研究期间，我们确定了31444名ROC孕妇和5558名威利茨孕妇的入院记录。与ROC相比，威利茨女性无论按代、年龄组或工厂关闭前后分层，流产风险都显著更高。正如对Cr(VI)暴露的动物研究预测的那样，无论何时暴露，威利茨女性的院内终止妊娠率仍然显著更高。在生命历程模型中，与ROC相比，非孕妇威利茨女性患生殖器官疾病和肿瘤的风险显著更高。
不良生殖结局有所增加，且与动物研究结果一致。总体健康结局反映出与职业暴露工人报告的相同广泛影响。首次报告了非职业性Cr(VI)暴露对人类女性及其婴儿的有害生殖影响。
