Effects of the 2018 Camp Fire on birth outcomes in non-human primates: Case-control study

Abstract

The November 2018 Camp Fire, a devastating wildfire in Northern California, occurred during the peak of breeding season for field monkeys at the California National Primate Research Center (CNPRC). Effects of environmental stressors, such as wildfires, on birth outcomes in primates, and in humans, are poorly understood. Additionally, wildfires are of growing concern due to their increasing frequency and severity. The objective was to examine the impact of wildfire smoke on fertility, timing of birth, and pregnancy loss for field monkeys. A unique case-control study to investigate birth outcomes in rhesus macaques ( Macaca mulatta ) was conducted at the CNPRC. All females in the study were maintained in outdoor fields during a period of elevated ambient wildfire smoke from November 8–22, 2018. In addition to ambient air quality evaluations, the effects on fertility, timing to birth, and pregnancy loss were documented. Archival records of approximately 5,000 conceptions from the previous nine years served as control data. During the Camp Fire, ambient fine particulate (PM 2.5 ) levels exceeded the 24 -h National Ambient Air Quality Standard (35 μg/m 3) of the United States Environmental Protection Agency, reaching levels as high as 185 μg/m 3. A statistically significant association was observed between birth loss and the 2018–2019 CNPRC breeding season. As this wildfire event occurred during various stages of early pregnancy, an association can be inferred between early gestational exposure and increased risk of pregnancy loss.

Adverse biobehavioral effects in infants resulting from pregnant rhesus macaques’ exposure to wildfire smoke

“…PM 2.5 also contains a mixture of metals, organic carbon, potassium, geologic material, and potentially ammonium nitrate 6 making it an ideal proxy measure for damage that can be caused by WFS. Because large number of structures (almost 19,000) were destroyed in the Camp Fire, including most of the town of Paradise, the smoke from this fire contained an unusual mixture of components:; Willson et al 7 reported high levels of phthalates, and a recent report by the California Air Resources Board 6 found significantly elevated levels of lead and zinc in the Camp Fire smoke associated, presumably, with the combustion of anthropogenic objects, such as houses, cars, and other objects containing plastics. Recent evidence suggests wildfire smoke (WFS) may also contain infectious microbes 8 .…”

A deletion at the polled PC locus alone is not sufficient to cause a polled phenotype in cattle

“…A similar phenomenon was seen in rhesus macaques at the California National Primate Research Center (CNPRC), only a mile away from where our recipients were housed. The rate of pregnancy loss in rhesus macaques exposed to the Camp Fire was almost double that of controls 29 . Although the miscarriage rate seen at the CNPRC (18%) was not as high as was seen in our recipients (50%), it is still possible the Camp Fire played a role in the fetal losses experienced in ET2.…”

Impacts from Wildfires on Livestock Health and Production: Producer Perspectives

“…These may include the cytotoxic effects of inhalation of oxygen-free radicals [ 78 ], or the disruption of fetal–maternal circulation [ 79 ], which have been shown to result in low birth weights and other poor birth outcomes [ 80 ]. A recent study reported miscarriage in Rhesus macaques naturally exposed to wildfire smoke, further supporting the need to expand research of these reproductive impacts of smoke on animals [ 54 ].…”

“…Researchers at the University of California, Davis, recently published a study on cats hospitalized with burns and smoke inhalation following the 2017–2018 California wildfires; the cats were shown to have significant cardiovascular changes based on serial echocardiograms [ 53 ]. Rhesus macaques housed at the California National Primate Research Center and naturally exposed to wildfire smoke were reported to have pregnancy losses following heavy smoke exposure [ 54 ]. Additionally, early data suggests that immune suppression may be evident in macaques even 12 years following smoke exposure [ 54 ].…”

“…Rhesus macaques housed at the California National Primate Research Center and naturally exposed to wildfire smoke were reported to have pregnancy losses following heavy smoke exposure [ 54 ]. Additionally, early data suggests that immune suppression may be evident in macaques even 12 years following smoke exposure [ 54 ]. These latest studies both document an association between smoke exposure and diverse pathologies, and highlight the lack of peer-reviewed research in this area, underscoring the need for additional information.…”