Household vacuum cleaners vs. the high-volume surface sampler for collection of carpet dust samples in epidemiologic studies of children

Background  

Levels of pesticides and other compounds in carpet dust can be useful indicators of exposure in epidemiologic studies, particularly for young children who are in frequent contact with carpets. The high-volume surface sampler (HVS3) is often used to collect dust samples in the room in which the child had spent the most time. This method can be expensive and cumbersome, and it has been suggested that an easier method would be to remove dust that had already been collected with the household vacuum cleaner. However, the household vacuum integrates exposures over multiple rooms, some of which are not relevant to the child's exposure, and differences in vacuuming equipment and practices could affect the chemical concentration data. Here, we compare levels of pesticides and other compounds in dust from household vacuums to that collected using the HVS3.     

Dynamic monitoring of the dust pickup efficiency of vacuum cleaners

This study evaluated a new method that uses an optical aerosol photometer for dynamically monitoring dust pickup efficiency during vacuuming. In the first stage of this study the new method was compared with built-in dirt sensors installed by vacuum cleaner manufacturers. Through parallel testing it has been shown that the widely available built-in dirt sensors are not sensitive enough to register small (< 53 microm) dust particles. Therefore, only the optical photometer was used in the rest of the experiments of this study to monitor the dust pickup efficiency while the vacuum cleaner was operated with different nozzles on clean and soiled carpet and vinyl sheet flooring. This method also was used to monitor dust pickup efficiency when vacuuming carpets originating from lead-contaminated homes. The dust pickup efficiencies obtained with the optical aerosol photometer have been compared with the surface lead concentrations found during different stages of cleaning. Results indicate that the dust mass concentration registered with the optical aerosol photometer at the nozzle outlet correlates well with the dust mass collected in the vacuum cleaner filter bag and with the surface lead level. Therefore, dynamic dust pickup monitoring can provide valuable information about the efficiency of cleaning when a vacuum cleaner is used. This suggests that a small aerosol photometer similar to a light-scattering smoke detector would be beneficial in vacuum cleaners used for cleaning surfaces contaminated with leaded dust and biological particles (including allergens).     

Chemical emissions from residential dryer vents during use of fragranced laundry products

Common laundry products, used in washing and drying machines, can contribute to outdoor emissions through dryer vents. However, the types and amounts of chemicals emitted are largely unknown. To investigate these emissions, we analyzed the volatile organic compounds (VOCs) both in the headspace of fragranced laundry products and in the air emitted from dryer vents during use of these products. In a controlled study of washing and drying laundry, we sampled emissions from two residential dryer vents during the use of no products, fragranced detergent, and fragranced detergent plus fragranced dryer sheet. Our analyses found more than 25 VOCs emitted from dryer vents, with the highest concentrations of acetaldehyde, acetone, and ethanol. Seven of these VOCs are classified as hazardous air pollutants (HAPs) and two as carcinogenic HAPs (acetaldehyde and benzene) with no safe exposure level, according to the US Environmental Protection Agency. As context for significance, the acetaldehyde emissions during use of one brand of laundry detergent would represent 3% of total acetaldehyde emissions from automobiles in the study area. Our study points to the need for additional research on this source of emissions and the potential impacts on human and environmental health.     

The vertical distribution of house dust mite allergen in carpet and the effect of dry vacuum cleaning

BACKGROUND: Carpets are large reservoirs of the dust mite allergen Der p 1. The effect of vacuum cleaning on the distribution of Der p 1 in carpets is poorly understood. METHODS: Samples were cut from 7 used household carpets, all over 5 years of age. From each carpet, 10 samples were left untreated, 10 vacuumed with an upright vacuum cleaner, and 10 vacuumed with a canister vacuum cleaner. Each section was then cut into 3 horizontal layers: the top 2mm, the remainder of the carpet pile, and the carpet base. The mass of Der p 1 as a proportion of carpet volume was then determined. RESULTS: The concentrations of Der p 1 in each depth layer varied considerably between the 7 untreated carpets. In the top layer, Der p 1 concentrations were (median; 25th-75th percentiles): 41.9; 28.3-92.6 pg/mm3. For the middle layer they were similar (38.1; 22.4-108.5 pg/mm3), and for the carpet base, higher (212.4; 98.8-456.2 pg/mm3). In most cases, cleaning using either type of vacuum cleaner resulted in no significant reduction in allergen concentration throughout all depth layers. A subset of carpets showed an apparent increase in Der p 1 concentration in one or more layers following vacuum cleaning. In all tests Der p 1 was collected in the vacuum cleaners' filter bags. CONCLUSIONS: The depth-distribution of Der p 1 differs widely amongst used carpets. Vacuum cleaning changes the distribution of Der p 1 within such carpets but does not necessarily result in a reduction in the overall content.     

Comparison of techniques to reduce residential lead dust on carpet and upholstery: the new jersey assessment of cleaning techniques trial

High-efficiency particulate air (HEPA) filtered vacuum cleaners are recommended by the U.S. Department of Housing and Urban Development for cleaning lead-contaminated house dust. We performed a randomized field study to determine whether a conventional (non-HEPA) vacuum cleaner could achieve cleaning results comparable with those of a HEPA vacuum cleaner. We compared the lead loading reductions of these two vacuum cleaners in a total of 127 New Jersey homes of lead-exposed children. We used wet towelettes and a vacuum sampler to collect lead dust from carpets and upholstery before and after vacuum cleaning. The vacuum sampling data showed that the HEPA and non-HEPA vacuum cleaners resulted in 54.7% (p = 0.006) and 36.4% (p = 0.020) reductions in lead loading, respectively, when used on soiled carpets, although the overall difference in lead loading reduction between the two vacuum cleaners was not statistically significant (p = 0.293). The wipe sampling data did not show any significant lead loading reduction for either of the vacuum cleaners, suggesting that both vacuum cleaners fail to clean the surfaces of carpet effectively, considering that wipe sampling media simulate surface contact. On upholstery, the wipe sampling data showed a significant reduction in lead loading for the non-HEPA vacuum cleaner (22.2%, p = 0.047). Even with the significant reduction, the postcleaning lead loadings on upholstery were similar to those on carpets. The similar lead loading results for carpets and upholstery indicate that soiled upholstery may be as important a source of childhood lead exposure as carpets.     

#51 Pesticides in carpet dust and self-reported pesticide use in four areas of the us

PURPOSE: As part of a case-control study of non-Hodgkin's lymphoma (NHL), exposure to home/garden pesticides is being assessed based on self-reported pest treatments and analysis of carpet dust samples. Here, we compare the study centers in terms of reported pesticide use and pesticide levels in carpet dust sampled from control subjects' current homes.METHODS: Of 1,057 controls, 53 refused dust collection (5%). About half of those who consented were eligible (owned carpets 5 years and used vacuum cleaner within past year) (530 subjects). Southwest Research Institute sieved and extracted dust from a used vacuum cleaner bag collected from each subject's current home. For 513 samples with sufficient dust (78 in Detroit, 147 in Iowa, 127 in Los Angeles, and 161 in Seattle), analysis for 30 pesticides was performed by GC/MS.RESULTS: In LA, 85% of subjects treated for crawling insects in/around the home (excluding lawns/gardens), higher than any other site. Dust from LA had the highest median levels of propoxur, chlorpyrifos, diazinon, and permethrin, insecticides often used for crawling insects. Termite treatments were most prevalent in LA, consistent with LA's relatively high median levels of chlorpyrifos, permethrin, and chlordane. Although lawn/garden insects were treated most often in Seattle (61%), none of the lawn/garden insecticides analyzed were detected most frequently in Seattle. The herbicides 2,4-D and dicamba were highest in Iowa, which had the highest reported treatment of lawn/garden weeds (69%). The agricultural herbicides atrazine, alachlor, and metolachlor were detected only in Iowa.CONCLUSION: Dust levels of residential pesticides were generally reflective of self-reported pest treatment practices. Seattle's relatively low prevalence of lawn/garden insecticides in dust, despite high reported use of these pesticides, is perhaps related to the relatively moist climate in Seattle.     

Asthma risk, cleaning activities and use of specific cleaning products among Spanish indoor cleaners

OBJECTIVES: Recent studies have shown an excess risk of asthma for cleaners, but it is not clear which cleaning-related exposures induce or aggravate asthma. METHODS: Risk factors for asthma were studied among indoor cleaners participating in the Spanish part of the European Community Respiratory Health Survey in 1992. In 1998, 78 of the 91 subjects reporting cleaning-related jobs in 1992 were identified. Of these, 67 indoor cleaners were interviewed by telephone about their cleaning activities and their use of cleaning products in 1992. These data were related to asthma prevalence in 1992, and the cleaners were compared with a reference group of office workers. RESULTS: Asthma prevalence was 1.7 times higher [95% confidence interval (95% CI) 1.1-2.6] among the cleaners than among the referents, being highest among private home cleaners (3.3, 95% CI 1.9-5.8). The prevalence of housedust mite sensitization amounted to 28% for the home cleaners and was significantly (P<0.01) higher than for other indoor cleaners (3%), but similar to the corresponding prevalence of office workers (22%). More than half of the cleaners reported work-related respiratory symptoms. The asthma risk of the home cleaners was mainly associated with kitchen cleaning and furniture polishing, with the use of oven sprays and polishes. CONCLUSIONS: The asthma risk of Spanish cleaners is primarily related to the cleaning of private homes. This relationship may be explained by the use of sprays and other products in kitchen cleaning and furniture polishing.     

医院保洁员洗手情况调查分析

目的：了解病区保洁员的手部皮肤带菌情况及洗手效果。方法：采用问卷调查及对保洁员洗手前后对照采样培养的方法。结果：调查50名保洁员，洗手前手污染严重，菌落数最高达1560CFU/cm^2，最低12CFU／cm^2，平均菌落数为1730CFU／cm^2；接受培训与末接受培训洗手后，手采样的合格率差异有显性(P＜0．05)。结论：应加强对保洁员洗手知识、洗手技术培训及洗手效果的监督和监测。     

某地毯厂织毯工手指变形调查

对某地毯厂织毯工手指变形情况调查.结果显示织毯可致作业者手指变形,主要表现为食指尺侧弯.     

Sexual behaviour and substance use patterns amongst adolescent truck cleaners and risk of HIV / AIDS

This study was conducted at transport nagar in Indore, a major industrial and commercial center of Madhya Pradesh. Usually each truck has a staff of 3, comprising 1 senior driver, 1 junior driver, and a cleaner, usually a child or an adolescent. 210 such adolescent truck cleaners were surveyed by random sampling of the parked trucks present in the transport nagar. A semi-structured questionnaire was administered to these adolescents using the oral interview technique. The age distribution of the adolescents indicated that 17 were 15-16 years old, 63 were 16-17, 61 were 17-18, and 69 were 18-19. When the income was low, the owners or the senior drivers provided the meals and minor expenses. 80% of the adolescents were illiterate, 10.5% were literate, 6.2% had primary education, and 3.3% had middle school education. 88.1% of the cleaners were away from home for 24-28 days a month, 7.1% for less than 24 days, and 4.8% for over 28 days. 25.2% of the cleaners had a history of sexual activity, commonly with prostitutes. 88.6% of the senior drivers regularly visited prostitutes, and in many cases the adolescents' payment to the prostitute was financed by the senior driver. 94.3% of these adolescents had engaged in unprotected sexual intercourse, and the remaining 5.7% had used condoms infrequently. 98.5% of them had not heard of HIV and AIDS. 4.3% had a history of sexually transmitted diseases and had been treated by general practitioners. Substance abuse was fairly common among these young people (140 smoked, 9 chewed tobacco, 2 used opium, and 2 used alcohol more than twice per week), and the cost for those substances was primarily met by the senior truck driver or the owner. The trend was similar for sexual activity, as 25.2% had engaged in sex (12.9% once, 7.1% twice, and 5.2% several times). Special programs are required for these adolescents to educate them about the risks of unprotected sex and drugs in order to prevent them from contracting HIV/AIDS.     

某市地毯厂工人听力损失调查

长期在噪声环境中工作,出现头晕、头疼、烦躁、失眠、多梦、注意力减退、血压升高、心律失常[1]等改变,严重会出现听力损伤及噪声聋。威海市各大地毯厂是从事噪声作业人员比较密集的企业,为了解地毯厂噪声作业工人听力损伤发生情况,我们对某地毯厂526名从事噪声作业工人进行职业健康检查及纯音听力测试,调查结果报告如下。     

三次预真空牙科灭菌器控制系统的研制

介绍了三次预真空牙科灭菌器控制系统的研制，用PIC系列单片机作为控制器，实现对密闭容器内汽液混合状态下的蒸汽温度、压力值的采集与控制。硬件电路上实现了温度、压力值的线性化测量，控制策略上采用模糊控制技术，实验结果表明，该控制器可使系统实现无超调、无静差、鲁棒性强等特点。     

Comparison of pesticides and other compounds in carpet dust samples collected from used vacuum cleaner bags and from a high-volume surface sampler.

Epidemiologic studies of the association between residential pesticide use and cancer risk require an assessment of past pesticide exposures. Pesticide levels in carpet dust are believed to reflect long-term pesticide use. Recent epidemiologic studies have found collection of dust samples using the high-volume surface sampler (HVS3) to be expensive and cumbersome. We compared the levels of pesticides and other compounds in dust obtained from subjects' personal used vacuum cleaner bags to that collected by the HVS3 to see if this simpler method could replace the HVS3 in epidemiologic research. We visited the homes of 15 subjects, took the used bags from their vacuums, and collected carpet dust samples with the HVS3. The samples were analyzed for 42 target compounds: 26 pesticides, 10 polycyclic aromatic hydrocarbons (PAHs), and six polychlorinated biphenyl (PCB) congeners using GC/MS in selected ion monitoring mode. The two methods agreed in detecting the presence of the target compounds between 80% and 100% of the time. Neither sampling method was consistently more sensitive. The median target compound concentrations were similar, and a paired t-test showed no significant differences. For many compounds, the concentrations of compounds in the HVS3 samples were higher than those in the used bag samples at the upper end of the concentration ranges. However, the Spearman rank correlation coefficients were 0.85 or higher for most compounds, indicating that homes would be ranked similarly using both methods. Overall, there appears to be no clear difference in the quality of the pesticide, PAH, or PCB concentration data for the two dust collection methods.