Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-6 (of 6 Records) |
Query Trace: Aldridge M[original query] |
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Does prior exposure to larvicides influence dengue virus susceptibility in Aedes aegypti (Diptera: Culicidae)?
Aldridge RL , Alto BW , Roxanne Connelly C , Okech B , Siegfried B , Eastmond BH , Alomar AA , Linthicum KJ . J Med Entomol 2023 Control of mosquito vector populations is primarily intended to reduce the transmission of pathogens they transmit. Use of chemical controls, such as larvicides, can have unforeseen consequences on adult traits if not applied properly. The consequences of under application of larvicides are little studied, specifically the impacts on pathogen infection and transmission by the vectors that survive exposure to larvicides. We compared vector susceptibility of Aedes aegypti (L.) for dengue virus, serotype 1 (DENV-1) previously exposed as larvae to an LC50 of different classes of insecticides as formulated larvicides. Larval exposure to insect growth regulators (methoprene and pyriproxyfen) significantly increased susceptibility to infection of DENV-1 in Ae. aegypti adults but did not alter disseminated infection or transmission. Larval exposure to temephos, spinosad, and Bti did not increase infection, disseminated infection, or transmission of DENV-1. Our findings describe a previously under observed phenomenon, the latent effects of select larvicides on mosquito vector susceptibility for arboviruses. These data suggest that there are unintended consequences of sublethal exposure to select larvicides that can influence susceptibility of Ae. aegypti to DENV infection, and indicates the need for further investigation of sublethal effects of insecticides on other aspects of mosquito biology, especially those parameters relevant to a mosquitoes ability to transmit arboviruses (life span, biting behavior, extrinsic incubation period). |
Lethal and sublethal concentrations of formulated larvicides against susceptible aedes aegypti
Aldridge RL , Alto BW , Connelly CR , Okech B , Siegfried B , Linthicum KJ . J Am Mosq Control Assoc 2022 38 (4) 250-260 Chemical control of vectors depends on the effective application of formulated insecticides. In this study we evaluated formulated larvicides using a larval bioassay against susceptible Aedes aegypti. The estimated larvicide lethal concentrations for 50% mortality (LC50s) were 25.7 μg/liter (Natular 2EC), 3.13 μg/liter (Abate 4E), 0.43 μg/liter (Altosid), 0.03 μg/liter (Nyguard), and 500.6 ITU/liter (VectoBac12AS containing Bacillus thuringiensis israelensis). Sublethal effects were identified and documented from adults that survived exposure to these estimated LC50s (body size and sex proportion). We observed changes in net growth as measured by adult wing lengths. For those larvae exposed to estimated LC50s, the average size of adults was between 0.1% and 10.6% smaller for males and between 1.1% and 13.6% smaller for females compared to controls. Sex proportions varied between larvicides, but some were significantly different from the control, favoring greater survival of females than males. |
Chemical emissions from heated vitamin e acetate-insights to respiratory risks from electronic cigarette liquid oil diluents used in the aerosolization of (9)-thc-containing products
LeBouf RF , Ranpara A , Ham J , Aldridge M , Fernandez E , Williams K , Burns DA , Stefaniak AB . Front Public Health 2021 9 765168 As of February 18, 2020, the e-cigarette, or vaping, product use associated lung injury (EVALI) outbreak caused the hospitalization of a total of 2,807 patients and claimed 68 lives in the United States. Though investigations have reported a strong association with vitamin E acetate (VEA), evidence from reported EVALI cases is not sufficient to rule out the contribution of other chemicals of concern, including chemicals in either THC or non-THC products. This study characterized chemicals evolved when diluent oils were heated to temperatures that mimic e-cigarette, or vaping, products (EVPs) to investigate production of potentially toxic chemicals that might have caused lung injury. VEA, vitamin E, coconut, and medium chain triglyceride (MCT) oil were each diluted with ethanol and then tested for constituents and impurities using a gas chromatograph mass spectrometer (GC/MS). Undiluted oils were heated at 25°C (control), 150°C, and 250°C in an inert chamber to mimic a range of temperatures indicative of aerosolization from EVPs. Volatilized chemicals were collected using thermal desorption tubes, analyzed using a GC/MS, and identified. Presence of identified chemicals was confirmed using retention time and ion spectra matching with analytic standards. Direct analysis of oils, as received, revealed that VEA and vitamin E were the main constituents of their oils, and coconut and MCT oils were nearly identical having two main constituents: glycerol tricaprylate and 2-(decanoyloxy) propane-1,3-diyl dioctanoate. More chemicals were measured and with greater intensities when diluent oils were heated at 250°C compared to 150°C and 25°C. Vitamin E and coconut/MCT oils produced different chemical emissions. The presence of some identified chemicals is of potential health consequence because many are known respiratory irritants and acute respiratory toxins. Exposure to a mixture of hazardous chemicals may be relevant to the development or exacerbation of EVALI, especially when in concert with physical damage caused by lung deposition of aerosols produced by aerosolizing diluent oils. |
Carbon monoxide emission rates from roasted whole bean and ground coffee
LeBouf RF , Aldridge M . J Air Waste Manag Assoc 2018 69 (1) 89-96 Carbon monoxide (CO) emitted from roasted coffee is a potential occupational respiratory exposure hazard to workers within the coffee industry. The current study objective was to estimate CO emission factors from commercially-available roasted whole and ground coffee measured in loose-form, not packaged, and to assess the utility of CO monitoring in non-ventilated storage spaces such as within coffee roasting and packaging facilities, transport vessels, and cafes. Determinants affecting CO emissions from coffee were investigated including form (whole vs. ground), roast level (Light, Medium, Medium-Dark, Dark), and age (time since the package was opened). CO emissions factors were estimated for roasted coffee samples from a variety of manufacturers purchased from local grocery stores and online. Emissions tests were performed on 36 brands of coffee with more than one sample per brand and with various roast levels. Decaying source equations or smoothing functions were fitted to the CO concentration measurements. Maximum observed emission factors at the peak of the predicted concentration curve were adjusted by the time required to reach the maximum CO concentration, and reported as emissions factors (EFbuildup). Ground coffee had a significantly increased EFbuildup (p < 0.0001) compared to whole bean. Roast level did not significantly affect emissions for whole bean coffee (p = 0.72), but did for ground (p < 0.001) coffee. For ground coffee, Medium-Dark and Dark roasts had significantly higher emissions than Medium and Light roasts. Worst-case emissions factors from commercially-available whole and ground coffee measured in loose-form, not packaged, showed that roasted coffee can rapidly emit CO. CO concentrations should be monitored in storage spaces in service and manufacturing facilities as well as transport vessels to ensure exposures do not exceed occupational exposure limits. Storage spaces may need to be ventilated to control CO concentrations to safe levels. |
Estimation of breast cancer incident cases and medical care costs attributable to alcohol consumption among insured women aged <45 years in the U.S
Ekwueme DU , Allaire BT , Parish WJ , Thomas CC , Poehler D , Guy GP Jr , Aldridge AP , Lahoti SR , Fairley TL , Trogdon JG . Am J Prev Med 2017 53 S47-s54 INTRODUCTION: This study estimated the percentage of breast cancer cases, total number of incident cases, and total annual medical care costs attributable to alcohol consumption among insured younger women (aged 18-44 years) by type of insurance and stage at diagnosis. METHODS: The study used the 2012-2013 National Survey on Drug Use and Health, cancer incidence data from two national registry programs, and published relative risk measures to estimate the: (1) alcohol-attributable fraction of breast cancer cases among younger women by insurance type; (2) total number of breast cancer incident cases attributable to alcohol consumption by stage at diagnosis and insurance type among younger women; and (3) total annual medical care costs of treating breast cancer incident cases attributable to alcohol consumption among younger women. Analyses were conducted in 2016; costs were expressed in 2014 U.S. dollars. RESULTS: Among younger women enrolled in Medicaid, private insurance, and both groups, 8.7% (95% CI=7.4%, 10.0%), 13.8% (95% CI=13.3%, 14.4%), and 12.3% (95% CI=11.4%, 13.1%) of all breast cancer cases, respectively, were attributable to alcohol consumption. Localized stage was the largest proportion of estimated attributable incident cases. The estimated total number of breast cancer incident alcohol-attributable cases was 1,636 (95% CI=1,570, 1,703) and accounted for estimated total annual medical care costs of $148.4 million (95% CI=$140.6 million, $156.1 million). CONCLUSIONS: Alcohol-attributable breast cancer has estimated medical care costs of nearly $150 million per year. The current findings could be used to support evidence-based interventions to reduce alcohol consumption in younger women. |
A new methodological approach to adjust alcohol exposure distributions to improve the estimation of alcohol-attributable fractions
Parish WJ , Aldridge A , Allaire B , Ekwueme DU , Phelps D , Guy GP Jr , Thomas CC , Trogdon JG . Addiction 2017 112 (11) 2053-2063 BACKGROUND AND AIMS: To assess the burden of excessive alcohol use, researchers routinely estimate alcohol-attributable fractions (AAFs). However, underreporting in survey data can bias these estimates. We present an approach that adjusts for underreporting in the estimation of AAFs, particularly across subgroups. This framework is a refinement of a previous method (Rehm et al., 2010). METHODS: We use a measurement error model to derive the "true" alcohol distribution from a "reported" alcohol distribution. The "true" distribution leverages per capita sales data to identify the distribution average and then identifies the shape of the distribution with self-reported survey data. Data are from the National Alcohol Survey (NAS), the National Household Survey on Drug Abuse (NHSDA), and the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). We compared our approach with previous approaches by estimating the AAF of female breast cancer cases. RESULTS: Compared with Rehm et al.'s approach, our refinement performs similarly under a gamma assumption. For example, among females aged 18-25, the two approaches produce estimates from NHSDA that are within a percentage point. However, relaxing the gamma assumption generally produces more conservative evidence. For example, among females aged 18-25, estimates from NHSDA based on the best-fitting distribution are only 19.33 percent of breast cancer cases, which is a much smaller proportion than the gamma-based estimates of about 28 percent. CONCLUSIONS: A refinement of Rehm et al.'s approach to adjusting for underreporting in the estimation of alcohol-attributable fractions provides more flexibility. This flexibility can avoid biases associated with failing to account for the underlying differences in alcohol consumption patterns across different study populations. Comparisons of our refinement with Rehm et al.'s approach show that results are similar when a gamma distribution is assumed. However, results are appreciably lower when the best-fitting distribution is chosen versus gamma-based results. |
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