The national outbreak of e-cigarette, or vaping, product use-associated lung injury has been the first vaping related disease to affect thousands of people . At its core, it is a chemical inhalation injury, most likely caused by heating, aerosolization and inhalation of Vitamin E within THC liquids and vape pens. Examination of airways and lungs of those affected has yielded a pattern of epithelial and alveolar damage. Neutrophils and foamy macrophages are often documented, with lipid laden phagosomes when directly tested through appropriate lipid stains; however, lipid laden macrophages are most likely evidence of vaping in general, not specific to EVALI. Although it has been clear for years that users of e-cigarettes and vaping devices were inhaling known toxins such as diacetyl and formaldehyde, this disease entity was the first to demonstrate that inhalation of clouds of chemicals that have never been tested for safety via inhalation methods can lead to significant impacts on public health. EVALI was first recognized in August 2019, with the number of recognized cases rising precipitously until December 2019. The connection with THC was made within several weeks – approximately 82% of those affected had vaped THC – while the identification of Vitamin E acetate as a prime suspect took months, and has not been confirmed as the etiologic agent at this time. Fourteen percent of those affected vaped nicotine containing e-liquids only, but upon review these subjects were older, female and had less leukocytosis, suggesting that they may have been suffering from a different vaping induced lung disease. Overall, EVALI is a disease of the young, with a median age of 24 years. It also predominantly affects males , which may be directly related to epidemiologic patterns of THC vaping. The majority of patients present with respiratory , gastrointestinal and systemic symptoms, and are found to have elevations in erythrocyte sedimentation rate , Creactive protein ,cannabis grow equipment white blood cell counts, and liver function tests. Beyond these factors, bilateral lung infiltrates are the key diagnostic finding on radio graphic imaging. The mortality rate is quite low, at 2.4% , with the highest mortality rate in older e-cigarette users with comorbidities. The median age of deceased EVALI patients was 49.5 years, with a range from 15 up to 75 years.

Of the cases identified up to December, approximately 47% required ICU admission and 22% required intubation. Because only moderate to severe cases were tracked, the reported numbers are likely to severely underestimate those affected. Since Vitamin E acetate within THC e-liquids has been identified as a likely causal agent, and with the intense media coverage of this disease entity, there is hope that the incidence of this particular vaping disease will decrease. However, as vaping increases across society, with millions of users inhaling hundreds of thousands of chemicals including lipophilic agents similar to VEA, it is clear that vaping associated lung diseases are here to stay. Conventional tobacco has been smoked for over 5000 years and is very well known to cause a myriad of long-term health problems, not the least of which is lung disease. Because modern vaping devices have been on the market for less than 16 years, and only widely used for 5, very little is known about how chronic use will affect human health. Murine dataSince they were first introduced in the 1970s more than 30 synthetic pyrethroids have been commercialized . Their rapid control of insects, relatively low toxicity to mammals and rapid degradation in the environment has made pyrethroids a very important class of insecticides, and they are commonly used worldwide. The federally mandated phase-out of residential uses of the organophosphate pesticides chlorpyrifos and diazinon in 2001 has caused further increases in the usage of pyrethroids indoors . This class of insecticides has a remarkably good safety profile, particularly compared to earlier materials that they replaced. There are cautions with regard to human exposure however. Many studies have shown that high levels of exposure to pyrethroids may cause significant toxicity and health effects. Pyrethroids are acute neurotoxins . They have shown immunotoxic effects and negative effects on mammalian reproduction , and they are reported to likely be carcinogenic to humans . Exposure in the general population results from ingestion of foods such as fruits and vegetables onto which the insecticide has been applied; drinking water; and inhalation, dermal contact and non-dietary ingestion resulting from residential indoor application.

In agricultural communities poor housing conditions can make homes more difficult to clean, potentially leading to a larger pest problem and in turn an increased use of pesticides in the indoor environment . Factors related to farm proximity, including drift from agricultural application and take-home contamination from occupational use, may also have a large influence on exposure to pesticides . Because children have an increased risk of exposure to environmental contaminants as compared to adults children living in agricultural communities are especially susceptible to pesticide exposure . A number of major pyrethroids such as permethrin, cypermethrin, deltamethrin, and fenvalerate are metabolized to 3-phenoxybenzoic acid . This urinary metabolite has been commonly used as a generic biomarker for evaluating human exposure to multiple pyrethroid pesticides . Traditionally, instrumental analytical methods are used to determine 3PBA in urine samples. More recently however, a lower-cost bio-analytical approach using an enzyme-linked immunosorbent assay has been developed and shown to be a suitable alternative method for the analysis of 3PBA in urine samples for exposure monitoring . The city of Mendota is located in agriculturally intensive Fresno County, in California’s Central Valley. According to the USDA’s 2007 Census of Agriculture, Fresno County had 6,081 farms, comprising over 1.6 million acres of land. It was ranked one of the top three counties in the U.S. for either total value or total acreage of agricultural products for the following commodities: cotton and cottonseed; vegetables, melons, potatoes, and sweet potatoes; fruits, tree nuts, and berries; grapes; tomatoes; vegetables harvested for sale; and almonds . With almost 29 million pounds of pesticide active ingredients applied in Fresno County, the highest of any county in California, in 2009 it can be assumed that there is a high risk of pesticide exposure to the farm workers, their families and people living in the surrounding areas. This study was conducted to examine the sources of pyrethroid pesticide exposure in the homes of farm worker families living in Mendota, California. We report housing conditions and exposure data collected in 2009 on pyrethroid pesticides measured by questionnaires and urinary concentrations of the metabolite 3PBA among 105 women, 23–51 years of age and 103 children, 2–8 years of age.

The Mexican Immigration to California: Agricultural Safety and Acculturation Study is a prospective cohort sample of 467 hired farm worker family households from Mendota, CA designed to evaluate occupational and environmental exposures of significance for a farm working population. Households were sampled from randomly selected census blocks and, following door-to-door enumeration, those households containing at least one hired farm worker were contacted for recruitment. Eligible participants in the MICASA study included men and women, residing in Mendota, CA, ages 18–55 years, self-identified as Mexican or Central American, with at least one household member who worked in agriculture 45 days or more in the previous year . MICASA recruitment and baseline interviews were conducted between January 2006 and May 2007. A follow-up interview was conducted between February 2009 and June 2010. Recruitment for the home pyrethroid exposure study began in February of 2009 and sample collection took place between June and December of 2009. In total, 843 participants, representing 467 households, completed the MICASA baseline interview. The analysis highlighted in this paper was designed to look at sources of pyrethroid exposure in the homes of the MICASA study population. As children typically have higher levels of exposure to pesticides ,PIPP horticulture we restricted eligibility to those MICASA families with at least one child aged 7 or under at the time of recruitment in order to better understand the sources in this potentially highly exposed population. Among the MICASA households completing baseline interviews, 175 were eligible for participation in the home pyrethroid exposure study. Eligible households were placed in random order for contact. One hundred twenty seven households were contacted for recruitment before reaching our goal of 105 households who agreed to participate and were enrolled in the study. The remaining 22 households either could not be contacted or declined to participate. If a family had multiple eligible children, one child was randomly selected and enrolled. At the time of sample collection, children ranged from 2 to 8 years of age. Written informed consent was obtained from each participant. Each study component was described verbally and in writing to the participant prior to obtaining written informed consent. Spanish was the primary language of the participants, thus the study description and written informed consent were provided in Spanish. All study procedures were approved by the University of California, Davis Institutional Review Board.

Data collected between June and December of 2009 consisted of urine samples, questionnaires and food recall. As collecting 24-hour urine samples can be difficult for participants, a more convenient end of-day single spot void urine sample was collected from each mother and enrolled child.Plastic bonnets, to be placed under the toilet seat , and prelabeled standard plastic urine cups were provided for urine collection. Total volume of void, time of void collection and time of previous void were recorded. Participants were instructed to store their urine sample in the provided coolers with ice packs overnight until study staff retrieved the samples the following day. Urine samples were then refrigerated at the MICASA field office for generally less than one day, delivered on ice to UC Davis where they were stored in a −80°C freezer until sample extraction and analysis. At the time of urine collection, a questionnaire was administered to the mothers. We obtained the frequency of pesticide use in both the hot and cold season of the previous year. Pesticide use encompassed any type of pest control including sprays, foggers, sticky traps, bait traps, gels, and any application by professional exterminators. To assess the presence of insect or rodent problems in the home, we asked if anyone living in the home had seen rodents, rodent feces, live or dead roaches, roach feces or ants inside the home at any time in the last year. The overall condition of the home was assessed by a series of questions looking at the presence of various common household disrepair items with the aim of creating a summed Home Disrepair Score. These individual disrepair items included water damage, mold, plumbing leaks, rotten wood, holes/worn spots in flooring, walls, ceiling and/or counters, peeling paint and home security. On the day of urine collection, a staff member inventoried all pesticide products in the home, including their EPA registration number and active ingredients. Additional sources of data included pesticide use questions assessed at both MICASA baseline and follow-up interviews and asked of husband and wife in each household.Furthermore, at follow-up interview, an evaluation each participant’s home was conducted by trained staff members. Three assessments–Inside Housing Condition, Outside Housing Condition, and Home Cleanliness–were scored on a 4-point scale based on level of disrepair. The Inside Housing Condition included peeling paint, holes/cracks in walls or floors, stains on floors, and presence of rodents and/or insect feces inside the house. The Outside Housing Condition included peeling paint and landscape maintenance. Home Cleanliness assessed the difficulty level of keeping the home clean. The Inside Housing Condition was based only on the portion of the home visible during the interview, and the research staff did not look for the presence of water damage. Participants were asked to complete a 24-hour food diary for the day prior to urine collection. The diary was split into four sections: breakfast, lunch, dinner, and snacks. The participants were instructed to write down everything they ate or drank during the entire 24- hour period, including the number of servings of each item consumed. Due to the low education level of participants, we did not consider it feasible to collect more detailed serving size information. No information was collected on participants’ time activity. Urine samples were prepared and analyzed for 3PBA using a competitive inhibition ELISA adapted from previously reported methods . Briefly, 0.5 mL urine aliquots were treated by acid hydrolysis, followed by solid phase extraction with a mixed-mode column, and finally solvent exchanged into methanol .