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Pharmacokinetic Interactions of Drinking Water Contaminants
Published in Rhoda G.M. Wang, Water Contamination and Health, 2020
Ronald Brown, Jerry N. Blancato, David Young
Biological monitoring is widely used to assess exposure of workers to toxic substances in occupational settings; however, it is being increasingly used to assess exposure to environmental pollutants in nonoccupational settings as well. In terms of significance, exposure of humans to environmental pollutants and to ethanol, drugs, or such agents as cigarette smoke may be more important than coexposure to environmental pollutants because of the relatively greater dose of compounds taken intentionally for therapeutic or recreational purposes. For example, cigarette smoke is a well-known inducer of enzyme activity. Enzyme induction may in turn alter the levels of the biomarker in blood or urine. As a result, it may be useful also to measure cotinine (a metabolite of nicotine) in the urine of subjects selected for a biological monitoring study of environmental pollutants as an index of their exposure to tobacco smoke. For similar reasons, knowledge of each person's drug and ethanol intake is also important for the interpretation of biomarker data.
Measurement of Exposure and Dose
Published in Samuel C. Morris, Cancer Risk Assessment, 2020
Smoking is such an important confounding factor in epidemiological studies of environmental carcinogenesis and self-reporting is so often inaccurate (perhaps the product of self-deception on the part of smokers), that a biomarker which can provide a definite and quantitative measure of smoking is highly desirable. Moreover, a marker that could provide a quantitative measure of passive smoking—the involuntary exposure of nearby people to side-stream cigarette smoke—would also be of use. Some nicotine is excreted in the urine; it can be measured in the saliva, also. The rate of nicotine metabolism varies as much as fourfold among smokers, however, so nicotine levels in urine, while specific, do not provide an accurate quantitative indicator unless calibrated in each individual. Levels of cotinine, the major metabolite of nicotine, vary much less than residual nicotine levels; measured in urine, cotinine provides both a specific and relatively accurate quantitative measure of exposure to tobacco smoke. Thiocyanate, a metabolite of hydrogen cyanide (a component of cigarette smoke) has also been suggested as a biomarker for exposure to tobacco smoke; but cyanide is also a component of leafy vegetables, some nuts, and beer, so its metabolite is not specific to cigarette smoke (HHS, 1986).
Exposure Characterization
Published in Elizabeth L. Anderson, Roy E. Albert, RISK ASSESSMENT and INDOOR AIR QUALITY, 2019
Because of the large number of measurable compounds in ETS, researchers often focus on target compounds. Two important markers for exposure studies are vapor-phase nicotine and respirable suspended particles (RSP). Almost all (95% or more) of nicotine in ETS appears to be in the vapor phase and tobacco is the predominant source of nicotine. Tobacco burning also emits large amounts of RSP. Both are relatively easily measured, although a number of assumptions are usually necessary in order to estimate exposure. As noted above, cotinine is widely used as a biological marker indicating exposure to nicotine. Other biological markers are also used, including thiocyanate, carboxyhemoglobin, aromatic amines, and protein and DNA adducts. Again, these biological markers indicate that exposure has occurred but cannot precisely pinpoint the source; they can also vary across the population. Some markers are not specific; for example, carboxyhemoglobin also results from exposure to carbon monoxide from sources other than cigarettes.
Association between fluoride exposure and blood pressure in children and adolescents aged 6 to19 years in the United States: NHANES, 2013–2016
Published in International Journal of Environmental Health Research, 2023
Meng Guo, Francis-Kojo Afrim, Zhiyuan Li, Na Li, Xiaoli Fu, Limin Ding, Zichen Feng, Shuo Yang, Hui Huang, Fangfang Yu, Guoyu Zhou, Yue Ba
General demographic characteristics, including age, sex (boys and girls), race/ethnicity (Mexican American, non-Hispanic white, non-Hispanic black, and other races), and familiesʻ poverty income ratios (PIR) were collected by at-home interviews. PIR was calculated by dividing the annual family income by the poverty threshold determined annually by the US Department of Health and Human Services. Poverty status was classified as PIR <1 or ≥ 1 (Park et al. 2019). Body mass index (BMI) was calculated by dividing weight by the square of height in meters (kg/m2). Serum cotinine was determined by an isotope-dilution high performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry. Daily intake of calorie, sodium, calcium, and potassium exposure, which were also potential dietary risk factors of hypertension (Hermansen 2000), were obtained from the first 24-hour dietary recall interview. For each participant, calorie and nutrient intake were calculated by multiplying the frequency that each food item was reported by the calorie or nutrient content of the specified portion size. Nutritional values of all the dietary items and beverages were provided by the United States Department of Agriculture ‘s Food and Nutrient Database for Dietary Studies which regularly updates each cycle and supplies the nutrient profiles for every food and beverage reported in NHANES.
Evaluation of lead body burden in US adolescents
Published in Archives of Environmental & Occupational Health, 2022
Wen-Chao Ho, Yu-Sheng Lin, James L. Caffrey, Mohammed F. Faramawi
The glomerular filtration rate (eGFR) for teenagers in the current study was estimated using the creatinine-based bedside Schwartz equation:15 eGFR (ml/min/1.73m2)=0.413×(height/Scr). In the formula height is expressed in centimeters, and Scr is serum creatinine (mg/dL). Demographic characteristics including age, sex and race were obtained as self-reported information during the household interview. BMI was calculated from measured height and weight, and computed as recommended by CDC16 and recorded as BMI-for-age percentile by sex. The cohort was then grouped into four categories: obesity (≥95th percentile), overweight (≥85th percentile but <95th percentile), normal weight (≥5th percentile but normal <85th percentile, and underweight (<5 the percentile). Poverty income ratio (PIR), an indicator for socioeconomic status, was computed by dividing self-report family income by poverty thresholds, which was produced annually by the Census Bureau. The cutoff for PIR was set at 1, the federal poverty line. Exposure to environmental or active cigarette smoking was assessed by serum cotinine levels: > 0.05 ng/mL.17
Age, gender, and racial/ethnic differences in the association of triclocarban with adulthood obesity using NHANES 2013–2016
Published in Archives of Environmental & Occupational Health, 2020
Uloma Igara Uche, Christopher C. King
Potential confounding variables such as age, sex, race/ethnicity, socioeconomic status, smoking, education, creatinine, triclosan, and bisphenol A (BPA) were adjusted. Information on age, sex, race/ethnicity, socioeconomic status, and education were retrieved from a questionnaire. Sex was grouped as male and female. Race/ethnicity was grouped as non-Hispanic whites, non-Hispanic blacks, Mexican Americans, other Hispanics, and other races. Socioeconomic status was indicated using the poverty income ratio (PIR), calculated by dividing the family income by a poverty threshold. Poverty income ratio was then grouped into at/below poverty level and above poverty level. Education was categorized into less than 9th grade, 9–11th grade, high school grad/GED or equivalent, some college or AA degree, and college graduate or above. Triclosan, bisphenol A, and smoking have been associated with obesity,14,15,47 so were also included in the model. Smoking was indicated using serum levels of cotinine. Urinary concentrations of triclosan and bisphenol A were measured by an online SPE method coupled to high performance liquid chromatography and tandem mass spectrometry. Approximately 71% and 94% of study population had triclosan and BPA concentrations above the detection limits. For those with concentrations below, the detection limits values were also imputed. This value is the limit of detection divided by the square root of 2 as recommended by NHANES. Serum level of cotinine was measured using an isotope-dilution high-performance liquid chromatography/APCI tandem spectrometric method.