Geothermal Gases--Community Experiences, Perceptions, and Exposures in Northern California.

Lake County, California, is in a high geothermal-activity area. Over the past 30 years, the city of Clearlake has reported health effects and building evacuations related to geothermal venting. Previous investigations in Clearlake revealed hydrogen sulfide at levels known to cause health effects and methane at levels that can cause explosion risks. The authors conducted an investigation in multiple cities and towns in Lake County to understand better the risk of geothermal venting to the community. They conducted household surveys and outdoor air sampling of hydrogen sulfide and methane and found community members were aware of geothermal venting and some expressed concerns. The authors did not, however, find hydrogen sulfide above the California Environmental Protection Agency air quality standard of 30 parts per billion over one hour or methane above explosive thresholds. The authors recommend improving risk communication, continuing to monitor geothermal gas effects on the community, and using community reports and complaints to monitor and document geothermal venting incidents.

Don't change who we are but give us a chance: confronting the potential of community health worker certification for workforce recognition and exclusion.

BACKGROUND: For community health workers (CHWs) and promotores de salud (CHWs who primarily serve Latinx communities and are grounded in a social, rather than a clinical model of care), the process of certification highlights the tension between developing a certified workforce with formal requirements (i.e., certified CHWs) and valuing CHWs, without formal requirements, based on their roles, knowledge, and being part of the communities where they live and work (i.e., non-certified CHWs). California serves as an ideal case study to examine how these two paths can coexist. California's CHW workforce represents distinct ideologies of care (e.g., clinical CHWs, community-based CHWs, and promotores de salud) and California stakeholders have debated certification for nearly twenty years but have not implemented such processes. METHODS: We employed purposive sampling to interview 108 stakeholders (i.e., 66 CHWs, 11 program managers, and 31 system-level participants) to understand their perspectives on the opportunities and risks that certification may raise for CHWs and the communities they serve. We conducted focus groups with CHWs, interviews with program managers and system-level participants, and observations of public forums that discussed CHW workforce issues. We used a thematic analysis approach to identify, analyze, and report themes. RESULTS: Some CHW participants supported inclusive certification training opportunities while others feared that certification might erode their identity and undermine their work in communities. Some program managers and system-level participants acknowledged the opportunities of certification but also expressed concerns that certification may distance CHWs from their communities. Program managers and system-level participants also highlighted that certification may not address all challenges related to integrating CHWs into health care systems. CHWs, program managers, and system-level participants agreed that CHWs should be involved in certification discussions and decision making. CONCLUSIONS: To address participant concerns, our findings recommend California stakeholders build a voluntary certification process structured with multiple pathways to overcome entry barriers of traditional certification processes, maintain CHW identity, and protect diversity within the workforce. Positioning CHWs as decision makers will be critical when designing state certification processes.

Mercury Toxicity and Contamination of Households from the Use of Skin Creams Adulterated with Mercurous Chloride (Calomel).

Inorganic mercury, in the form of mercurous chloride, or calomel, is intentionally added to some cosmetic products sold through informal channels in Mexico and the US for skin lightening and acne treatment. These products have led to multiple cases of mercury poisoning but few investigations have addressed the contamination of cream users' homes. We report on several cases of mercury poisoning among three Mexican-American families in California from use of mercury-containing skin creams. Each case resulted in widespread household contamination and secondary contamination of family members. Urine mercury levels in cream users ranged from 37 to 482 µg/g creatinine and in non-users from non-detectable to 107 µg/g creatinine. Air concentrations of up to 8 µg/m³ of mercury within homes exceeded the USEPA/ATSDR health-based guidance and action level of <1.0 µg/m³. Mercury contamination of cream users' homes presented a multi-pathway exposure environment to residents. Homes required extensive decontamination, including disposal of most household items, to achieve acceptable air levels. The acceptable air levels used were not designed to consider multi-pathway exposure scenarios. These findings support that the calomel is able to change valence form to elemental mercury and volatilize once exposed to the skin or surfaces in the indoor environment.

Direct measurement of perchlorate exposure biomarkers in a highly exposed population: a pilot study.

Exposure to perchlorate is ubiquitous in the United States and has been found to be widespread in food and drinking water. People living in the lower Colorado River region may have perchlorate exposure because of perchlorate in ground water and locally-grown produce. Relatively high doses of perchlorate can inhibit iodine uptake and impair thyroid function, and thus could impair neurological development in utero. We examined human exposures to perchlorate in the Imperial Valley among individuals consuming locally grown produce and compared perchlorate exposure doses to state and federal reference doses. We collected 24-hour urine specimen from a convenience sample of 31 individuals and measured urinary excretion rates of perchlorate, thiocyanate, nitrate, and iodide. In addition, drinking water and local produce were also sampled for perchlorate. All but two of the water samples tested negative for perchlorate. Perchlorate levels in 79 produce samples ranged from non-detect to 1816 ppb. Estimated perchlorate doses ranged from 0.02 to 0.51 µg/kg of body weight/day. Perchlorate dose increased with the number of servings of dairy products consumed and with estimated perchlorate levels in produce consumed. The geometric mean perchlorate dose was 70% higher than for the NHANES reference population. Our sample of 31 Imperial Valley residents had higher perchlorate dose levels compared with national reference ranges. Although none of our exposure estimates exceeded the U. S. EPA reference dose, three participants exceeded the acceptable daily dose as defined by bench mark dose methods used by the California Office of Environmental Health Hazard Assessment.