Olorunfemi Adetona

Organophosphorus and pyrethroid insecticide urinary metabolite concentrations in young children living in a southeastern United States city.

Pesticide metabolites are routinely measured in the urine of children in the United States. Although the sources of these metabolites are believed to include residues in food from agricultural applications and residues from applications in everyday environments (e.g., homes), few studies have been able to demonstrate an association between indoor residential pesticide applications and pesticide metabolite concentrations. To better quantify the effects of potential risk factors related to demographics, household characteristics, occupation, and pesticide use practices on urinary biomarker levels, we performed a study in a city (Jacksonville, Florida) previously determined to have elevated rates of pesticide use. We enrolled a convenience sample of 203 children ranging in age from 4 to 6 years; their caregivers completed a questionnaire and the children provided a urine sample, which was analyzed for a series of organophosphorus and pyrethroid insecticide metabolites. The questionnaire responses substantiated much higher pesticide use for the study participants as compared to other studies. Urinary metabolite concentrations were approximately an order of magnitude higher than concentrations reported for young children in other studies. Few statistically significant differences (at the p<0.05 level) were observed, however, several trends are worth noting. In general, mean urinary pesticide metabolite concentrations were higher for males, Caucasians, and those children living in homes with an indoor pesticide application occurring within the past four weeks. Comparing the urinary pesticide metabolite concentrations in this study to those reported in the NHANES and GerES studies showed that the children living in Jacksonville had substantially higher pyrethroid pesticide exposures than the general populations of the United States and Germany. Further research is needed in communities where routine pesticide use has been documented to obtain information on the most important routes and pathways of exposure and to develop the most effective strategies for reducing pesticide exposures for children.

Inflammatory Effects of Woodsmoke Exposure Among Wildland Firefighters Working at Prescribed Burns at the Savannah River Site, SC

Wildland firefighters in the United States are occupationally exposed to high levels of woodsmoke. Results from experimental studies show that exposure to woodsmoke induces inflammation. A study was conducted to investigate the effect of occupational woodsmoke exposure on inflammatory biomarkers in firefighters working at prescribed burns. Twelve U.S. Forest Service wildland firefighters at the Savannah River Site, South Carolina, volunteered to give blood samples during four prescribed burns between February and March 2011. Twenty-four paired (pre- and post-work shift) blood samples were collected using dried blood spot method to facilitate repeated sample collection. Inflammatory biomarker concentrations in blood samples were measured using the Meso Scale Discovery multi-spot assay system. Concurrent personal PM2.5 and CO monitoring of firefighters was conducted. Linear mixed models were used to test whether cross-work shift differences occurred in the following inflammatory biomarkers: IL-1β, IL-8, CRP, SAA, ICAM-1, and VCAM-1. IL-8 showed a significant cross-work shift difference as indicated by a post/pre-work shift ratio of 1.70 (95% CL: 1.35, 2.13; p = 0.0012). Concentrations of IL-8, CRP, and ICAM-1 increased in >50% of samples across work shift. Firefighters who lighted fires as opposed to other work tasks had the largest cross-work shift increase in IL-8. A significant cross-work shift increase in IL-8 in blood samples was observed in healthy wildland firefighters working at prescribed burns. Further research is needed to understand the physiological responses underlying the adverse effects of woodsmoke exposure, and the dose-response relationship between woodsmoke exposure and inflammatory responses.

Household air pollution: a call for studies into biomarkers of exposure and predictors of respiratory disease

Household air pollution (HAP) from indoor burning of biomass or coal is a leading global cause of morbidity and mortality, mostly due to its association with acute respiratory infection in children and chronic respiratory and cardiovascular diseases in adults. Interventions that have significantly reduced exposure to HAP improve health outcomes and may reduce mortality. However, we lack robust, specific, and field-ready biomarkers to identify populations at greatest risk and to monitor the effectiveness of interventions. New scientific approaches are urgently needed to develop biomarkers of human exposure that accurately reflect exposure or effect. In this Perspective, we describe the global need for such biomarkers, the aims of biomarker development, and the state of development of tests that have the potential for rapid transition from laboratory bench to field use.

Review of the health effects of wildland fire smoke on wildland firefighters and the public

Abstract Each year, the general public and wildland firefighters in the US are exposed to smoke from wildland fires. As part of an effort to characterize health risks of breathing this smoke, a review of the literature was conducted using five major databases, including PubMed and MEDLINE Web of Knowledge, to identify smoke components that present the highest hazard potential, the mechanisms of toxicity, review epidemiological studies for health effects and identify the current gap in knowledge on the health impacts of wildland fire smoke exposure. Respiratory events measured in time series studies as incidences of disease-caused mortality, hospital admissions, emergency room visits and symptoms in asthma and chronic obstructive pulmonary disease patients are the health effects that are most commonly associated with community level exposure to wildland fire smoke. A few recent studies have also determined associations between acute wildland fire smoke exposure and cardiovascular health end-points. These cardiopulmonary effects were mostly observed in association with ambient air concentrations of fine particulate matter (PM2.5). However, research on the health effects of this mixture is currently limited. The health effects of acute exposures beyond susceptible populations and the effects of chronic exposures experienced by the wildland firefighter are largely unknown. Longitudinal studies of wildland firefighters during and/or after the firefighting career could help elucidate some of the unknown health impacts of cumulative exposure to wildland fire smoke, establish occupational exposure limits and help determine the types of exposure controls that may be applicable to the occupation.

Biomonitoring of polycyclic aromatic hydrocarbon exposure in pregnant women in Trujillo, Peru — Comparison of different fuel types used for cooking ☆

Women and children in developing countries are often exposed to high levels of air pollution including polycyclic aromatic hydrocarbons (PAHs), which may negatively impact their health, due to household combustion of biomass fuel for cooking and heating. We compared creatinine adjusted hydroxy-PAH (OH-PAH) concentrations in pregnant women in Trujillo, Peru who cook with wood to levels measured in those who cook with kerosene, liquefied petroleum gas or a combination of fuels. Seventy-nine women were recruited for the study between May and July 2004 in the first trimester of their pregnancy. Urine samples were collected from the subjects in the first, second and third trimesters for OH-PAH analyses. The concentrations of the OH-PAHs were compared across the type of fuel used for cooking and pregnancy trimesters. The relationships between OH-PAHs levels in the first trimester and concurrently measured personal exposures to PM₂.₅, carbon monoxide and nitrogen dioxide together with their indoor and outdoor air concentrations were also investigated. Women cooking with wood or kerosene had the highest creatinine adjusted OH-PAH concentrations compared with those using gas, coal briquette or a combination of fuels. Concentrations of creatinine adjusted 2-hydroxy-fluorene, 3-hydroxy-fluorene, 1-hydroxy-fluorene, 2-hydroxy-phenanthrene and 4-hydroxy-phenanthrene were significantly higher (p<0.05) in women who used wood or kerosene alone compared with women who used liquefied petroleum gas (LPG), coal briquette or a combination of fuels. An increase in the concentrations of creatinine adjusted 9-hydroxy-fluorene, 1-hydroxy-phenanthrene, 2-hydroxy-phenanthrene, 4-hydroxy-phenanthrene and 1-hydroxy-pyrene in the third trimesters was also observed. Weak positive correlation (Spearman correlation coefficient, ρ<0.4; p<0.05) was observed between all first trimester creatinine adjusted OH-PAHs and indoor (kitchen and living room), and personal 48-h TWA PM₂.₅. Women who cooked exclusively with wood or kerosene had higher creatinine adjusted OH-PAH levels in their urine samples compared to women who cooked with LPG or coal briquette.

Personal PM2.5 Exposure Among Wildland Firefighters Working at Prescribed Forest Burns in Southeastern United States

This study investigated occupational exposure to wood and vegetative smoke in a group of 28 forest firefighters at prescribed forest burns in a southeastern U.S. forest during the winters of 2003–2005. During burn activities, 203 individual person-day PM2.5 and 149 individual person-day CO samples were collected; during non-burn activities, 37 person-day PM2.5 samples were collected as controls. Time-activity diaries and post-work shift questionnaires were administered to identify factors influencing smoke exposure and to determine how accurately the firefighters’ qualitative assessment estimated their personal level of smoke exposure with discrete responses: “none” or “very little,” “low,” “moderate,” “high,” and “very high.” An average of 6.7 firefighters were monitored per burn, with samples collected on 30 burn days and 7 non-burn days. Size of burn plots ranged from 1–2745 acres (avg = 687.8). Duration of work shift ranged from 6.8–19.4 hr (avg = 10.3 hr) on burn days. Concentration of PM2.5 ranged from 5.9–2673 μg/m3 on burn days. Geometric mean PM2.5 exposure was 280 μg/m3 (95% CL = 140, 557 μg/m3, n = 177) for burn day samples, and 16 μg/m3 (95% CL = 10, 26 μg/m3, n = 35) on non-burn days. Average measured PM2.5 differed across levels of the firefighters’ categorical self-assessments of exposure (p < 0.0001): none to very little = 120 μg/m3 (95% CL = 71, 203 μg/m3) and high to very high = 664 μg/m3 (95% CL = 373, 1185 μg/m3); p < 0.0001 on burn days). Time-weighted average PM2.5 and personal CO averaged over the run times of PM2.5 pumps were correlated (correlation coefficient estimate, r = 0.79; CLs: 0.72, 0.85). Overall occupational exposures to particulate matter were low, but results indicate that exposure could exceed the ACGIH®-recommended threshold limit value of 3 mg/m3 for respirable particulate matter in a few extreme situations. Self-assessed exposure levels agreed with measured concentrations of PM2.5. Correlation analysis shows that either PM2.5 or CO could be used as a surrogate measure of exposure to woodsmoke at prescribed burns.

Changes in the concentrations of biochemical indicators of diet and nutritional status of pregnant women across pregnancy trimesters in Trujillo, Peru, 2004–2005

BackgroundIn developing countries, deficiencies in essential micronutrients are common, particularly in pregnant women. Although, biochemical indicators of diet and nutrition are useful to assess nutritional status, few studies have examined such indicators throughout pregnancy in women in developing countries.MethodsThe primary objective of this study was to assess the nutritional status of 78 Peruvian women throughout pregnancy for 16 different nutritional indicators including fat-soluble vitamins and carotenoids, iron-status indicators, and selenium. Venous blood samples from which serum was prepared were collected during trimesters one (n = 78), two (n = 65), three (n = 62), and at term via the umbilical cord (n = 52). Questionnaires were completed to determine the demographic characteristics of subjects. Linear mixed effects models were used to study the associations between each maternal indicator and the demographic characteristics.ResultsNone of the women were vitamin A and E deficient at any stage of pregnancy and only 1/62 women (1.6%) was selenium deficient during the third trimester. However, 6.4%, 44% and 64% of women had ferritin levels indicative of iron deficiency during the first, second and third trimester, respectively. Statistically significant changes (p ≤ 0.05) throughout pregnancy were noted for 15/16 nutritional indicators for this Peruvian cohort, with little-to-no association with demographic characteristics. Three carotenoids (beta-carotene, beta-cryptoxanthin and trans-lycopene) were significantly associated with education status, while trans-lycopene was associated with age and beta-cryptoxanthin with SES (p < 0.05). Concentrations of retinol, tocopherol, beta-cryptoxanthin, lutein + zeaxanthin and selenium were lower in cord serum compared with maternal serum (p < 0.05). Conversely, levels of iron status indicators (ferritin, transferrin saturation and iron) were higher in cord serum (p < 0.05).ConclusionThe increasing prevalence of iron deficiency throughout pregnancy in these Peruvian women was expected. It was surprising though not to find deficiencies in other nutrients. The results highlight the importance of continual monitoring of women throughout pregnancy for iron deficiency which could be caused by increasing fetal needs and/or inadequate iron intake as pregnancy progresses.

Personal Exposure to PM2.5 and Urinary Hydroxy-PAH Levels in Bus Drivers Exposed to Traffic Exhaust, in Trujillo, Peru

Public transport vehicle drivers, especially in highly polluted or trafficked areas, are exposed to high levels of air pollutants. In this study, we assessed the influence of traffic on levels of hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) in commercial bus drivers in Trujillo, Peru, by measuring the within-shift changes in the urinary whole weight and creatinine-corrected concentrations of the PAH metabolites. We measured personal PM2.5 as a proxy of exposure to traffic emission. Urine samples were collected daily from two bus drivers and three minivan drivers in Trujillo, pre-, mid-, post-work shift and on days when the drivers were off work (total n = 144). Ten OH-PAH metabolites were measured in the urine samples. Drivers were also monitored for exposure to PM2.5 (n = 41). Daily work shift (mean = 13.1 ± 1.3 hr) integrated PM2.5 was measured in the breathing zones of the drivers for an average of 10.5 days per driver. The differences across shift in OH-PAH concentrations were not statistically significant except for urinary 2-hydroxyfluorene (2-FLU) (p = 0.04) and 4-hydroxyphenanthrene (4-PHE) (p = 0.01) and creatinine-corrected 4-hydroxyphenanthrene (p = 0.01). Correlation between pairs of hydroxy-PAHs (ρ = 0.50 to 0.93) were highest for mid-shift samples. Concentrations of PM2.5 (geometric mean = 64 μg/m3; 95% confidence limits = 52 μg/m3, 78 μg/m3) is similar to those measured in many other studies of traffic exposure. There was significant change across work shift for concentrations of only two of the OH-PAHs (2-FLU and 4-PHE). Results indicate that the drivers may have had limited time for clearance of PAH exposure from the body between work shifts. Comparisons of the concentrations of creatinine-corrected hydroxy-PAH to those reported in other studies indicate that exposure of public transport drivers to PAH could be similar. By following the subjects over multiple days, this study gives an indication of appropriate exposure situations for the use of hydroxy-PAHs and will be beneficial in designing future occupational studies of PAH exposure.

Lung function changes in wildland firefighters working at prescribed burns.

Context: Although decline in lung function across workshift has been observed in wildland firefighters, measurements have been restricted to days when they worked at fires. Consequently, such results could have been confounded by normal circadian variation associated with lung function. Objectives: We investigated the across-shift changes in lung function of wildland firefighters, and the effect of cumulative exposure on lung function during the burn season. Materials and Methods: We measured forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), forced expiratory flow from 25% to 75% of FVC (FEF25–75), and peak expiratory flow (PEF) of wildland firefighters before and after their workshifts. In all, 501 pre-shift and 488 post-shift measurements were collected over 22 prescribed burn days and 43 non-burn days from 24 non-smoking wildland firefighters during the dormant winter burn seasons of 2003 and 2004. We compared changes in the spirometry measures across the workshift on burn days to those observed on non-burn days. We also assessed the effect of cumulative exposure during the burn season on the spirometry measures. Results: There were no significant differences in the across workshift changes on burn days compared to those on non-burn days for all the spirometry measures. However, for a given point in time during the season, each additional day of exposure was estimated to be associated with declines of 24 ml in pre-shift FVC and 24 ml in pre-shift FEV1 (p <0.01). Discussion and Conclusion: Cumulative exposure to woodsmoke was associated with slight decrements in lung function among the wildland firefighters.

Exposure of Pregnant Women to Cookstove-Related Household Air Pollution in Urban and Periurban Trujillo, Peru

Although evidence suggests associations between maternal exposure to air pollution and adverse birth outcomes, pregnant womens exposure to household air pollution in developing countries is understudied. Personal exposures of pregnant women (N = 100) in Trujillo, Peru, to air pollutants and their indoor concentrations were measured. The effects of stove-use-related characteristics and ambient air pollution on exposure were determined using mixed-effects models. Significant differences in 48-hour kitchen concentrations of particulate matter (PM2.5), carbon monoxide (CO), and nitrogen dioxide (NO2) concentrations were observed across fuel types (p < 0.05). Geometric mean PM2.5 concentrations where 112 μg/m3 (confidence limits [CLs]: 52, 242 μg/m3) and 42 μg/m3 (21, 82 μg/m3) in homes where wood and gas were used, respectively. PM2.5 exposure was at levels that recent exposure-response analyses suggest may not result in substantial reduction in health risks even in homes where cleaner burning gas stoves were used.