High Volume Small Surface Sampler Research Articles

Factors influencing household organophosphate pesticide levels in agricultural communities

Background Organophosphate (OP) pesticide exposure is associated with various cancers, neurodegenerative diseases, and respiratory health outcomes. Proximity to agricultural operations and direct occupational contact are hypothesized to be important routes of exposure. Understanding these routes and exploring methods to estimate exposure will improve epidemiological studies, especially among agricultural communities where pesticide exposure due to drift and indirect contact is disproportionally high. To understand factors that influence household environmental exposures to OPs, we collected dust samples from homes in the Central Valley of California. We hypothesized that OP levels would be higher among samples collected during the agricultural spraying season and from homes in which a household member worked in agriculture. Methods Household dust samples were collected using a high-volume small surface sampler during the agricultural spraying (June) and non-spraying (January) seasons from 28 households located within 200 feet of agricultural fields. T-tests and paired t-tests were conducted to assess differences in total OP levels by occupational status and spraying season. Results A total of 50 samples were analyzed for the presence of OPs. Homes in which a household member worked in agriculture had significantly higher OP levels (130.0 parts per billion (ppb), SD 168.5), compared to homes without anyone working in agriculture (28.7 ppb, SD 24.2; p-value=0.001). No statistically significant differences were detected by spraying season (t=0.41, p-value = 0.69). Conclusions Our results demonstrate that detectable levels of OPs are prevalent in households within 200 feet of agricultural fields. Additionally, OPs may persist indoors for extended periods of time. Although the California Pesticide Use Registry indicates that OP application in our study area is seasonal, dust samples had similar levels across seasons. Our work will inform future research by revealing important factors related to routes of exposure to harmful pesticides experienced by agricultural workers and their families.

Immunological and genotoxic effects of occupational exposure to α-cypermethrin pesticide.

The aim of this work has been to find out the occupational oxidative stress, immunological and genotoxic health hazards among α-cypermethrin (CYP) pesticide-exposed workers. A cross-sectional study was performed including 200 workers divided into 3 groups according to the level of exposure: highly exposed group (50 workers), moderately exposed group (50 workers) and unexposed group (100 workers). All workers were subjected to detailed laboratory investigation for gene P53 mutations, immunological parameters as a cluster of differentiation into 3 percentage (CD3%), CD4% and CD8% in addition to peripheral blood total leukocytic and platelet counts that were measured. Spectrophotometer technique was used for detection of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx). Air samples were collected with a High Volume Small Surface Sampler for measurement of α-cypermethrin level. A highly exposed group to the α-cypermethrin had lower CD4/CD8 as compared to an unexposed group with statistically significant difference. As regards gene mutation, exons 5a and 6 were more frequent among the highly exposed group as compared to no mutation among moderately exposed and unexposed groups with significant difference. As regards antioxidants; SOD, CAT, GSH and GPx were higher among the unexposed group as compared to the highly and moderately exposed group with statistically significant difference. Significant negative correlation was found between working years and antioxidant parameters. Repeated exposure to α-CYP may lead to gene mutations, immunological disturbances and oxidative stress. Strict safety precautions are required not only for workers but also for public users. Int J Occup Med Environ Health 2017;30(4):603-615.

Predictors of polybrominated diphenyl ether (PBDE) serum levels in a cohort of U.S. children aged 1-5 years

Introduction. We investigated predictors of polybrominated diphenyl ether (PBDE) serum concentrations among young children in the southeastern United States. Methods. Serum levels of PBDE congeners (BDE-47, -99, -100, -153, -154, -209) were measured via gas chromatography-tandem mass spectrometry in a sample of 81 healthy children aged 1-5 years who were under anesthesia for ear tube surgery. Demographics and behaviors such as smoking and breastfeeding were reported by parents on a questionnaire; a research nurse recorded anthropometric measures and insurance status. In a subset of 17 children, PBDEs were measured in a house dust sample collected with a solvent-cleaned high volume small surface sampler (HVS3) vacuum, and from two hand wipes sampled from the child at a home visit. In linear and Tobit regression we modeled natural log-transformed serum PBDE levels of the most frequently detected congeners (PBDE-153 and ∑BDE-47,-99,-100) as a function of child characteristics, including median household income in the child’s residential zip code from the U.S. Census. Results. A $10,000 increase in median income in a child’s zip code was associated with a 21% (95%CI=9-32%) lower serum BDE-153 concentration and a 17% (95%CI=6–27%) lower serum concentration of ∑BDE-47,-99,-100. A similar pattern was observed for other markers of socioeconomic status. Higher BMI z-score was associated with lower serum levels of BDE-153, but not ∑BDE-47,-99,-100. Among the subset of children who participated in a home visit, serum PBDEs were positively correlated with hand wipe PDBEs, most strongly for ∑BDE-47,-99,-100 (Spearman r=0.48), but not dust PBDEs. Conclusions. Results suggest socioeconomic factors are strong predictors of serum PBDE levels among young children in the southeastern United States. This study adds to the evidence indicating PBDEs measured on hand wipes are more predictive of serum PBDE levels than vacuum-collected dust from the home.

Dust metal loadings and the risk of childhood acute lymphoblastic leukemia.

We evaluated the relationship between the risk of childhood acute lymphoblastic leukemia (ALL) and the levels of metals in carpet dust. A dust sample was collected from the homes of 142 ALL cases and 187 controls participating in the California Childhood Leukemia Study using a high volume small surface sampler (2001-2006). Samples were analyzed using microwave-assisted acid digestion in combination with inductively coupled plasma mass spectrometry for arsenic, cadmium, chromium, copper, lead, nickel, tin, tungsten, and zinc. Eight metals were detected in at least 85% of the case and control homes; tungsten was detected in <15% of homes. Relationships between dust metal loadings (μg metal per m(2) carpet) and ALL risk were modeled using multivariable logistic regression, adjusting for the child's age, sex, and race/ethnicity and confounders, including household annual income. A doubling of dust metal loadings was not associated with significant changes in ALL risk (odds ratio (95% confidence interval): arsenic: 0.96 (0.86, 1.07), cadmium: 0.92 (0.81, 1.05), chromium: 1.01 (0.90, 1.14), copper: 0.97 (0.91, 1.03), lead: 1.01 (0.93, 1.10), nickel: 0.95 (0.82, 1.09), tin: 0.96 (0.86, 1.08), and zinc: 0.94 (0.84, 1.05)). Our findings do not support the hypothesis that metals in carpet dust are risk factors for childhood ALL.

Polycyclic aromatic hydrocarbons in residential dust and risk of childhood acute lymphoblastic leukemia

Several polycyclic aromatic hydrocarbons (PAHs) are known or probable human carcinogens. We evaluated the relationship between PAH exposure and risk of childhood acute lymphoblastic leukemia (ALL) using concentrations in residential dust as an exposure indicator. We conducted a population-based case-control study (251 ALL cases, 306 birth-certificate controls) in Northern and Central California from 2001 to 2007. We collected residential dust using a high volume small surface sampler (HVS3) (n=185 cases, 212 controls) or by sampling from participants׳ household vacuum cleaners (n=66 cases, 94 controls). We evaluated log-transformed concentrations of 9 individual PAHs, the summed PAHs, and the summed PAHs weighted by their carcinogenic potency (the toxic equivalence). We calculated odds ratios (ORs) and 95% confidence intervals (CI) using logistic regression adjusting for demographic characteristics and duration between diagnosis/reference date and dust collection. Among participants with HVS3 dust, risk of ALL was not associated with increasing concentration of any PAHs based on OR perln(ng/g). Among participants with vacuum dust, we observed positive associations between ALL risk and increasing concentrations of benzo[a]pyrene (OR perln[ng/g]=1.42, 95% CI=0.95, 2.12), dibenzo[a,h]anthracene (OR=1.98, 95% CI=1.11, 3.55), benzo[k]fluoranthene (OR=1.71, 95% CI=0.91, 3.22), indeno[1,2,3-cd]pyrene (OR=1.81, 95% CI=1.04, 3.16), and the toxic equivalence (OR=2.35, 95% CI=1.18, 4.69). The increased ALL risk among participants with vacuum dust suggests that PAH exposure may increase the risk of childhood ALL; however, reasons for the different results based on HVS3 dust samples deserve further study.

Residential levels of polybrominated diphenyl ethers and risk of childhood acute lymphoblastic leukemia in California.

Background: House dust is a major source of exposure to polybrominated diphenyl ethers (PBDEs), which are found at high levels in U.S. homes.Methods: We studied 167 acute lymphoblastic leukemia (ALL) cases 0–7 years of age and 214 birth certificate controls matched on date of birth, sex, and race/ethnicity from the Northern California Childhood Leukemia Study. In 2001–2007, we sampled carpets in the room where the child spent the most time while awake; we used a high-volume small-surface sampler or we took dust from the home vacuum. We measured concentrations of 14 PBDE congeners including penta (28, 47, 99, 100, 153, 154), octa (183, 196, 197, 203), and decaBDEs (206–209). Odds ratios (ORs) were calculated using logistic regression, adjusting for demographics, income, year of dust collection, and sampling method.Results: BDE-47, BDE-99, and BDE-209 were found at the highest concentrations (medians, 1,173, 1,579, and 938 ng/g, respectively). Comparing the highest to lowest quartile, we found no association with ALL for summed pentaBDEs (OR = 0.7; 95% CI: 0.4, 1.3), octaBDEs (OR = 1.3; 95% CI: 0.7, 2.3), or decaBDEs (OR = 1.0; 95% CI: 0.6, 1.8). Comparing homes in the highest concentration (nanograms per gram) tertile to those with no detections, we observed significantly increased ALL risk for BDE-196 (OR = 2.1; 95% CI: 1.1, 3.8), BDE-203 (OR = 2.0; 95% CI: 1.1, 3.6), BDE-206 (OR = 2.1; 95% CI: 1.1, 3.9), and BDE-207 (OR = 2.0; 95% CI: 1.03, 3.8).Conclusion: We found no association with ALL for common PBDEs, but we observed positive associations for specific octa and nonaBDEs. Additional studies with repeated sampling and biological measures would be informative.Citation: Ward MH, Colt JS, Deziel NC, Whitehead TP, Reynolds P, Gunier RB, Nishioka M, Dahl GV, Rappaport SM, Buffler PA, Metayer C. 2014. Residential levels of polybrominated diphenyl ethers and risk of childhood acute lymphoblastic leukemia in California. Environ Health Perspect 122:1110–1116; http://dx.doi.org/10.1289/ehp.1307602

Persistent organic pollutants in dust from older homes: learning from lead.

We aimed to (1) evaluate the relation between home age and concentrations of multiple chemical contaminants in settled dust and (2) discuss the feasibility of using lead hazard controls to reduce children's exposure to persistent organic pollutants. As part of the California Childhood Leukemia Study, from 2001 to 2007, we used a high-volume small surface sampler and household vacuum cleaners to collect dust samples from 583 homes and analyzed the samples for 94 chemicals with gas chromatography-mass spectrometry and inductively coupled plasma mass spectrometry. We evaluated relations between chemical concentrations in dust and home age with Spearman rank correlation coefficients. Dust concentrations of lead, polychlorinated biphenyls, organochlorine insecticides, and polycyclic aromatic hydrocarbons were correlated with home age (ρ > 0.2; P < .001), whereas concentrations of pyrethroid insecticides and polybrominated diphenyl ethers were not. Dust in older homes contains higher levels of multiple, persistent chemicals than does dust in newer homes. Further development of strategies to reduce chemical exposures for children living in older homes is warranted.

Performance of dust allergen carpet samplers in controlled laboratory studies

Allergens and other pollutants in house dust are collected using a variety of dust samplers that are assumed to operate similarly. This factorial design study compared sampler performance under controlled environmental conditions. House dust with known particle sizes (212-90, 90-45, and <45 μm) and allergen concentrations were sampled from new carpet squares with varying denier, pile height and pile densities. Dust mass and allergen recovery for total dust mites (Der p 1 and Der f 1), cat (Fel d 1) and cockroach allergen (Bla g 1) were assessed using the Eureka Mighty Mite (EURK), the High Volume Small Surface Sampler (HVS), or the American Industrial Hygiene Association (AIHA) method. Allergen concentrations were quantified using enzyme-linked immunosorbent assays, and dust mass results were corrected for carpet fiber shedding. Samplers were compared by exploring mass collection efficiency (CE=fiber corrected dust mass/applied dust mass) and concentration ratio (CR=allergen concentration in collected sample/allergen concentration in test dust). Test dust allergen concentrations varied by particle size fraction due to varying laboratory performance over time. The EURK and HVS samplers had CEs of 41-63% in the small and medium particle size fractions, and collected less than 20% of the available dust from the large size fraction. The AIHA CE ranged from 10% to 17% in the medium and small particle size fractions, but collected little dust in the largest particle size fraction. The AIHA and HVS samplers were more likely to acquire more representative and less variable allergen CRs compared with the EURK method. Health studies that use allergen concentration as an exposure metric need to consider the implications of sampler performance when interpreting links to health outcomes and development of health-based standards for allergens in house dust.

Determinants of polychlorinated biphenyls in dust from homes in California, USA.

Polychlorinated biphenyl (PCB) production ceased in the U.S. over 30 years ago, but these persistent chemicals remain ubiquitous contaminants. Here, we evaluate potential determinants of PCB levels in dust from California homes including characteristics of the residence as well as the residents' habits and occupations. Dust was collected from 415 households as part of a large case-control study (the Northern California Childhood Leukaemia Study), using a high-volume small surface sampler. Dust concentrations of 6 PCBs (PCB-105, PCB-118, PCB-138, PCB-153, PCB-170, and PCB-180) were measured using gas chromatography-mass spectrometry. Individual PCB detection rates ranged from 9% to 54% with PCB concentrations ranging from below detection (1 or 2 ng g (-1)) to 270 ng g(-1) and PCB loadings ranging from below detection to 960 ng m (-2). Multivariable linear and logistic regression models were used to identify potential determinants of residential PCB contamination based on in-home interviews and residential geographic locations. We observed that residences built prior to 1980 had higher odds of PCB detection and higher PCB loadings than more recently constructed homes. Households where residents typically did not remove their shoes had higher PCB dust loadings than households where residents did. PCBs were less likely to be detected in carpet dust from households that had frequently vacuumed or replaced carpets compared to other households. Since we used a cross-sectional dust sampling protocol and report significant, but modest, effects of these determinants on levels of PCBs in residential dust, our results should be interpreted with caution. Longitudinal studies to determine optimal strategies for reducing PCBs in homes are warranted.

House Dust Collection Efficiency of the High Volume Small Surface Sampler on Worn Carpets

The High Volume Small Surface Sampler (HVS3) is a dust-sampling vacuum that allows for set airflow and back pressure during sampling, increasing precision. Total dust collection efficiency of the HVS3 has been evaluated only on new carpets—not worn carpets. We performed a factorial study to assess the impact of carpet wear, dust deposition level, carpet type, and relative humidity during sampling on HVS3 collection efficiency. House dust was aerosolized in a 1-m3 exposure chamber and allowed to settle on test carpets and reference filters. Dust was embedded into the carpets and later extracted with the HVS3 under controlled environmental conditions according to established protocols. Overall collection efficiency was high, 88.3%. Collection efficiency was significantly higher at low relative humidity levels (30%) relative to high (75%) (p = < 0.0001), though differentially between cut-pile and closed-loop carpets. Collection efficiency of carpets with high wear was significantly lower than those with midlevel wear (p = 0.01). These results demonstrate that the design of the HVS3 partially corrects for differences in dust load and carpet type. However, collection efficiency of the HVS3 is affected by high levels of carpet wear and ambient humidity during sampling.

Measurement of Airborne and Floor Dusts in a Nonproblem Building

Part of a year-long study was to establish baseline measurements of airborne and surface dusts in a building. A four-story building was monitored with a laser particle counter (LPC) to characterize airborne particle size ranges of >0.5 to >15 m, a fine particle sampler (FPS) to measure 24-hour total airborne dust mass concentrations, and a high-volume small surface sampler (HVS3) to assess dust levels on floor surfaces. Monthly measurements were taken on each floor for 5 months. An improved cleaning regimen was instituted, and monitoring continued for 7 months. Mean LPC indoor particle counts correlated well with those outdoors (0.92). Mean LPC size distributions were similar on all floors, decreasing as particle size increased, and remained fairly constant over the study. FPS airborne dust mass concentrations were low throughout the building (5 to 11.5 g/m3). In comparing FPS and LPC measurements, mean 24-hour FPS total airborne dust mass measurements proved the most meaningful over a long term. LPC data...