Gram Of Dust Research Articles

Entraining of dust and steam flux in water pool: experimental and numerical simulations of vapor condensation and dust deposition

This paper deals with experimental tests of steam condensation in a water pool at atmospheric pressure and temperature in the range 15-100 °C. The activity is performed in the frame of a research program, funded by the ITER organization, for the study of dust deposition, produced in the ITER Vacuum Vessel and entrained by the steam and non condensable gas into the Pressure Suppression Tanks in the case of a Loss of Coolant Accident. The steam condensation into a subcooled water pool has been investigated to characterise the condensation regimes occurring during dust deposition tests. The dust distribution on the tank walls strongly depends on the steam jet length and on the effective heat transfer coefficient. Few grams of dust reduce the water transparency, therefore separated tests without dust overcome this drawback. Measurements of the lengths and surfaces of the steam jets (which permit to calculate effective average heat transfer) have been performed by means of image analyses and have been compared with theoretical correlations. The comparison showed a good agreement between the experimental data and theoretical correlations. Useful data have been obtained for implementing numerical models of dust deposition and for understanding the dust distribution on the tank wall obtained in the experimental tests.

Comparison of goose down and woolen pillows in terms of house dust mites

This study was conducted to compare the goose down and the woolen pillows in terms of number of house dust mites per gram of dust. The study was conducted in Kars province, Turkey in September 2020. A total of 180 house dust samples were collected from 45 randomly selected houses in various districts of the city. The number of houses in which at least one sample was positive regarding mites was found to be 39 (86.66%). Overall, 137 (76.11%) of dust samples were mite positive. This rate was 87.77% in dust samples of woolen and 64.44% in dust samples of goose down pillows. The number of mites/g dust varied between 15 and 625 in mite-positive woolen pillows, 10 and 420 in mite-positive goose down pillows. Mean number of mites per g of dust was 127.67 in woolen pillows and 79.39 in goose down pillows. A statistically significant difference was found between woolen and goose down pillows in terms of the number of mites per gram of dust (P<0.05). A total of 1,362 mite specimens were isolated from the dust samples. As a result of the identification of isolated specimens; a total of 16 species belong to 10 genera and 6 families were determined. Of these; Dermatophagoides pteronyssinus (Trouessart, 1897) (65.85%), Lepidoglyphus destructor (Schrank) (9.25%) and Acarus siro Linnaeus (6.16%) were the most dominant species in terms of number of specimens.

House dust mites (Acari: Astigmata) from mattresses in Panama

The name “house dust mites” is commonly used to refer to species of mites belonging mainly to the Pyroglyphidae family (Astigmata) that are found in association with dust in the human dwellings. They represent the main source of allergens in the home and can cause allergic diseases. Mattresses often provide ideal conditions for mite colonization. In order to compare the diversity of house dust mites in the provinces of Panama and Panama Oeste in 2015, we collected dust from the surfaces of mattresses over an area of one square meter using the vacuum method. We obtained 50 samples using the vacuum method and recovered 10,225 mites. We found that the mites in our samples belonged to 15 families, 15 genera and 22 morphospecies. Relatively, high mean densities of mites per gram of dust on mattresses were obtained in the provinces of Panama (3,577 mites/g of dust) and Panama Oeste (6,273 mites/g of dust). The mite Blomia tropicalis was the most abundant species in mattresses in the Province of Panama and Dermatophagoides pteronyssinus was the most frequent one in Panama Oeste. Our results indicate that the mite community in mattresses is similar between PA and PO. However, our results differ significantly from those found in bedroom floors in a previous study. These differences correspond to a lower species richness, higher density and relative abundance of Astigmata mites in mattresses.

House dust endotoxin, asthma and allergic sensitization through childhood into adolescence.

BackgroundHouse dust endotoxin may have beneficial effects on allergic sensitization and asthma in children. Evidence is scarce for adolescents and most studies so far have been cross‐sectional and limited to a single exposure measurement.ObjectiveWe assessed associations of house dust endotoxin with asthma and allergic sensitization from birth to age 17 years longitudinally taking into account exposure early in life and at primary school age.MethodsWe used data of 854 participants of the prospective Dutch PIAMA birth cohort study with house dust endotoxin measurements at 3 months and/or 5‐6 years and data on asthma and/or allergic sensitization from at least one of 11 follow‐ups until age 17. We assessed overall and age‐specific associations of the prevalence of asthma and sensitization with mattress and living room floor dust concentrations (per gram of dust) and loads (per m2 of sampling surface).ResultsHigher living room floor dust endotoxin concentrations at 3 months were associated with lower odds of asthma until age 4 [odds ratio (95% confidence interval) ranging from 0.70 (0.51‐0.97) at age 1 to 0.76 (0.57‐1.00) at age 3 per interquartile range increase], but not thereafter in children of allergic mothers. Higher living room floor dust endotoxin at 5‐6 years was associated with higher odds of sensitization at 8‐16 years [eg odds ratio (95% confidence interval) 1.70 (1.17‐2.47) per interquartile range increase in endotoxin load].Conclusions and clinical relevanceHouse dust endotoxin may have beneficial effects on asthma in preschool children of allergic mothers, which do not persist into adolescence. Beneficial associations with allergic sensitization could not be confirmed.

Comparison of the domestic mites abundance in dwellings on selected urban and rural areas of the Zawiercie district (south-west Poland).

Mites are found in all types of environments, inhabiting also the immediate human environments, including dust from sleeping accommodations, upholstered furniture or carpeted floors. It is commonly known that house dust mites are sources of potent inhalant allergens. Dermatophagoides pteronyssinus and Dermatophagoides farinae belong to the most common species in the temperate climate zone. Samples were collected by using a portable vacuum cleaner, into trap-filters installed onto the cap for dusting. Then, mites were isolated by a flotation method with saturated NaCl solution. The Petri dishes were screening under a stereoscopic microscope for presence of mites, then isolated mites were mounted on microscopic slides in Hoyer's medium. Mites were identified to species under the light microscope using phase contrast optics. A total of 724 mites were isolated from 46 of the examined samples, including 666 (91.9%) members of the family Pyroglyphidae. Among them D. pteronyssinus was predominat (62.8% of the total count, with average number 211.22 specimens per 1 gram of dust), followed by D. farinae (24.03%, averagely 150.07 specimens per 1 gram of dust) and Euroglyphus maynei (4.42%, 118.11 specimens per 1 gram of dust). Higher density of house dust mites was associated with the following factors: higher age of building, higher number of roommates, higher washing frequency per week, presence of carpeted floor in bedrooms, wooden floors in kitchens, closed kitchen, uphoplstered furniture, absence of pets and unemployed housewives.

Removal of Dust from the Solar Panel Surface using Mechanical Vibrator

Soiling and its effect on the performance of solar modules are generally of high concern for regions with a high deposition of dust and low frequency and less intensity of rainfall. The procedure of removing dust using traditional methods is capital and labour intensive. Additionally, most of the cleaning methods consumed power from the energy produced by the solar system. Therefore, the main objective of this study is to investigate the effect of vibration magnitude on the dust removal index of solar panel. In this work, wind energy was transformed into mechanical energy i.e. vibration. The mechanical vibrator attached to a panel produced harmonic excitation force to overcome the adhesive force between the dust particles and the surface of the solar panel. The generated vibration force has a linear relationship with the air velocity. This new designed and fabricated system was able to remove 3.5 gram of dust out of 5 grams on the panel with a vibration force of 3.128 N at a tilt angle of 15°. The new system has effectively proven that wind energy if being converted into vibration force can be used for dust removal from the solar panel surface.

Gambaran Kepadatan Tungau Debu Rumah Spesies Dermatophagoides pteronyssinus dan Dermatophagoides farinae di Kelurahan Jati Kecamatan Padang Timur Kota Padang

House dust mite is closely associated with the incidence of allergies such as asthma, atopic dermatitis and allergic rhinitis. Spesies of house dust mite which has been proven to be related with the incidence of allergies are Dermatophagoides pteronyssinus and Dermatophagoides farinae. The purpose of this study is to describe the density of house dust mites species in residence houses in Kelurahan Jati. The study was a descriptive study with 96 samples taken from two habitats, namely beds and carpets in 48 homes that have been selected randomly. House dust mites were identified using a light microscope with magnification of 40 times. The results showed that 56 of 96 samples were positive of house dust mites. This study showed that Dermatophagoides pteronyssinus was the most commonly found spesies of house dust mite (71 mites) with the highest density in the bed (6.88 mites/ gram of dust). Species Dermatophagoides farinae only found as many as 5 mites with the highest density in the carpet (0.46 mites/ gram of dust). The conclusion of this research is the density of house dust mites in Kelurahan Jati are quite low so that the possibility to cause allergic diseases is very small.

Dynamika sezonowa i struktura populacji roztoczy Dermatophagoides w kurzu z miejsc do spania na terenie Sosnowca

The typical members of house dust mites are species of the family Pyroglyphidae. The most medically important and most widely distributed species of the family are Dermatophagoides pteronyssinus, Dermatophagoides farinae and Euroglyphus maynei. The aim of the study was to show the temporal changes in abundance and structure of dust mite populations in dwellings throughout the year. A total of 48 dust samples from beds and other sleeping accommodations from 4 flats located on the territory of Sosnowiec were analysed. The examined flats were dominated by mites of the genus Dermatophagoides. Among them D. farinae was predominant. The highest density of D. farinae per gram of dust was observed in autumn, in time when the most favourable conditions of indoor temperature and relative humidity for these mites were noted. Relatively high numbers of nymphs of D. farinae in the examined sleeping accommodations in autumn are indicative of the development of populations during this period.

Sensitivity to House Dust Mites Allergens in Patients with Allergic Asthma in Erzincan Province, Turkey.

To investigate the sensitivity of allergic asthma (AA) patients to house dust mites (HDM) by conducting skin tests, measuring total and specific IgE antibodies to Dermatophagoides pteronyssinus and D. farinae mites, and examining HDM fauna in patients' homes. The study included 25 patients with AA and 31 healthy controls, who were challenged with Der p and Der f allergens; serum levels of allergen-specific lgE and total IgE were measured. Dust samples were collected from the homes of all participants, and mite species and the number of mites per gram of dust were investigated. D. pteronyssinus was found in the homes of 94.7% patients with positive Der p reactions in the skin test (p<0.001). D. farinae was found in the homes of 22.2% patients with positive Der f reactions in the skin test (p>0.05). D. pteronyssinus-specific IgE was detected in 75% patients in whose homes D. pteronyssinus was also found, while D. farinae-specific IgE was detected in 16.6% patients in whose homes D. farinae was also found. A part of AA patients residing in Erzincan are sensitive to HDM allergens, and high numbers of mites leading to allergic sensitization are found in their homes.

Ara h2 levels in dust from homes of individuals with peanut allergy and individuals with peanut tolerance.

Approximately 1% of the U.S. population has a peanut allergy. Previous studies that measured peanut protein in house dust support the hypothesis that household peanut consumption may lead to clinical sensitization through transdermal exposure. The aim of this pilot study was to characterize Ara h2 levels in house dust from homes with and without individuals with peanut allergy. Household dust was obtained from homes with an individual with peanut allergy and from homes with no individual with peanut allergy. Ara h2 levels were determined by using a monoclonal antibody-based immunoassay with a level of determination of 150 ng per gram of dust. Peanut consumption information was obtained by questionnaire. A total of 85 dust samples were collected: 38 from homes with a individual with peanut allergy and 47 from control homes. The median Ara h2 level in homes with an individual with peanut allergy was 1236 ng/g (interquartile range [IQR], 256-1342 ng/g), whereas the median Ara h2 level in homes without an individual with peanut allergy was 650 ng/g (IQR, 163-2201 ng/g). Ara h2 levels in dust from homes of individuals with peanut allergy were not significantly lower than in dust from control homes. Of the homes with an individual with peanut allergy, 15 reported complete avoidance of peanut in the home (39%). Ara h2 levels in homes that completely avoided peanuts were not significantly lower than Ara h2 levels in homes that did not restrict peanuts (p = 0.531). Although families may restrict peanuts and peanut products in the home, there was still detectable Ara h2 levels found in homes. Each subject's definition of restriction may vary, there seemed to be peanut protein entering the home, although the protein origin is not known. Possibilities include cross-reactivity with another antigen or transport into the home on some vector. Further investigation of hypotheses regarding cross-reactivity and environmental exposure to Ara h2 is necessary.

NASA to launch asteroid-sampling mission

OSIRIS-REx plans to return more than 60 grams of dust from carbon-rich Bennu.

House Dust Mites in Erzincan Province.

We aimed to determine the species of the house dust mites seen in Erzincan, the number of mites per gram of dust in the houses, and the relationship between temperature and the number of mite specimens. For this purpose, 54 dust samples collected from 18 houses located in different districts of Erzincan province between November 2013 and January 2014. These samples were examined by a lactic acid precipitation method. Of the houses in which the dust samples were collected, 94.44% were found to be positive in terms of mites. A total of 844 mite specimens were isolated from the dust samples, and the mean number of mites per gram of dust was found to be 18.34. The most common species was found to be Acarus siro (55.55%) and was followed by Dermatophagoides pteronyssinus (50.00%), Tyrophagus putrescentiae (22.22%), Histiostoma sp. (22.22%), Lepidoglyphus destructor (16.66%), T. perniciosus(11.11%), Euroglyphus maynei (11.11%), Glycyphagus privatus (11.11%), Cheyletus sp. (11.11%), Tarsonemus sp. (11.11%), and Tetranychus sp. (11.11%). Mite-holding rate of the houses in Erzincan province was found to be 94.44%. The mean number of mites per gram of dust was found to be 18.34. The most common mite species was A. siro, which was followed by D. pteronyssinus.

Measurement of aeroallergens from furnace filters

BackgroundExposure assessment is an important component of allergic disease diagnosis and management. Analysis for allergen content in vacuumed dust has been used traditionally. ObjectiveTo study allergen levels of dust taken from high-efficiency furnace filters in Midwestern homes. MethodsFurnace filters used were FQT12 1-inch disposable filters with high-efficiency media placed in homes enrolled in the Kansas City Safe and Healthy Homes Project. Dust was removed from the filters by vacuuming. Fungal culture was used to obtain counts of viable spores. Aeroallergens Fel d1, Can f1, Mus m1, Der f1, Der p1, and Bla g2 and antigenic material from Alternaria, Aspergillus, Cladosporium, and Penicillium species were measured using commercially available immunoassay materials. ResultsSixty filters were recovered from 56 homes after an average 135 days in situ. Mean weight of dust recovered was 2.43 g and correlated well with the time the filter was in place. Viable spore counts ranged to 4.8 × 107 per gram of dust. Mean fungal antigenic material ranged to 42 μg per gram for Cladosporium species. Mean aeroallergen material ranged to 7 μg per gram for Fel d1. Aeroallergen measurements were above the level of detection in 100% of houses for Fel d1 and 89% of houses for Bla g2. Levels of Fel d1 and Can f1 were strongly positively correlated. ConclusionAllergens from 5 common aeroallergen species and antigenic material from 4 common fungal taxa can be measured in dust taken from high-efficiency furnace filters.

Laboratory dust generation and size-dependent characterization of metal and metalloid-contaminated mine tailings deposits

The particle size distribution of mine tailings material has a major impact on the atmospheric transport of metal and metalloid contaminants by dust. Implications to human health should be assessed through a holistic size-resolved characterization involving multidisciplinary research, which requires large uniform samples of dust that are difficult to collect using conventional atmospheric sampling instruments. To address this limitation, we designed a laboratory dust generation and fractionation system capable of producing several grams of dust from bulk materials. The equipment was utilized in the characterization of tailings deposits from the arsenic and lead-contaminated Iron King Superfund site in Dewey-Humboldt, Arizona. Results show that metal and metalloid contaminants are more concentrated in particles of <10μm aerodynamic diameter, which are likely to affect surrounding communities and ecosystems. In addition, we traced the transport of contaminated particles from the tailings to surrounding soils by identifying Pb and Sr isotopic signatures in soil samples. The equipment and methods developed for this assessment ensure uniform samples for further multidisciplinary studies, thus providing a tool for comprehensive representation of emission sources and associated risks of exposure.

Ozone reaction characteristics of indoor floor dust examined in the emission cell “FLEC”

Ozone reacts with C–C double bonds in common indoor VOCs and SVOCs contained in indoor dust and may be catalytically degraded on dust surfaces. The reaction between floor dust and ozone was investigated in the FLEC emission cell at different ozone concentrations and relative humidities (0%, 25%, and 50% RH). One gram of dust was spread on a clean stainless steel plate which was placed in the FLEC. Steady state reaction rate (kDust) at 2.2ppm ozone was determined for four different floor dust samples collected in Danish homes and offices. This high concentration was necessary in order to measure and determine the consumption in the outlet air from the FLEC. Measurements were corrected for FLEC wall effects by subtraction of the steady state reaction rate between ozone and a FLEC on a stainless steel plate without dust (kFLEC). The composition of organic compounds in the dust was analyzed by pressurized liquid extraction and thermal desorption GC–MS before and after ozone exposure.kFLEC was independent of the ozone concentration and the reaction was treated as first order. The same was indicated for kDust since it remained unchanged at 2.2 and 1.6ppm ozone for one dust sample. However, the measured kDust in the FLEC should be considered an average rate constant due to the FLEC geometry. kDust was in the range 0.039–0.14s-1 pr. g dust at 50% RH. kDust was 3 times higher at 25% RH than at 50% RH and 6 times higher than at 0% RH.The inhomogeneity of the dust was assessed by experiments in triplicate with a new portion of dust each time. The relative standard deviation of kDust at 50% RH was 6–20%.The major identified compounds before and after ozone exposure included aldehydes, saturated and unsaturated linear alkanoic acids, benzoic acid and their methyl esters, dimethyl esters, phthalates and traces of α-pinene and limonene. Substantial increase of C7–C9 aldehydes was observed after ozone exposure.

A comparison of subject room dust with home vacuum dust for evaluation of dust-borne aeroallergens

BackgroundAssessment of indoor allergen is valuable in exposure research and evaluation of allergic individuals. Collection methods range from grab vacuum samples to filtration devices located in the breathing range of an individual. For practical purposes, many research studies use analysis of collected house dust to evaluate allergen reservoirs. ObjectiveTo test the hypothesis that house dust collected from the family vacuum is equivalent to house dust collected by a technician following standard protocol. MethodsHomes from a healthy homes demonstration project (n = 41) were sampled using a specific Department of Housing and Urban Development–suggested protocol in the bedroom of the child with asthma and a simple grab procedure from the family vacuum. Samples were evaluated for the presence of 5 allergens, Bla g2, Can f1, Der f1, and Der p1 combined as total mite, Fel d1, and Mus m1. Samples were also evaluated for total antigenic protein from 4 fungal taxa, including Alternaria, Aspergillus, Cladosporium, and Penicillium. ResultsAll of the allergens and antigens tested showed good correlation between the 2 collection methods. Fungal antigens ranged up to 92,651 nanograms per gram of dust for Aspergillus, and allergens ranged up to 17,928 nanograms per gram of dust for Can f1. The best correlation was for Cladosporium (r = 0.91), and the weakest was for dust mite (r = 0.34). ConclusionAllergens and antigens tested from samples collected by protocol and by grab sampling from the home vacuum were highly positively correlated. Grab samples taken from the family vacuum may be a good surrogate for evaluating home allergen exposure.

Effects of dust particles on the dynamics of blobs in the scrape off layer II

A detailed analysis is performed of the results of numerical simulations of the dynamics of plasma blobs, obtained within the model of the nonlinear interchange mode, including the effects of the dissipation by dust, in tokamak scrape-off layer plasmas. The maximum distances that a plasma blob may travel in the radial direction are calculated under physical conditions characteristic for several large tokamaks that are presently in operation, and it is found that a relatively small amount of 30 nm carbon dust particulates, corresponding to only a few grams of dust in the entire scrape-off layer, may dissipate the blobs and prevent them from reaching the tokamak wall.

Presence and density of domestic mites in the microenvironment of mite‐sensitive dogs with atopic dermatitis

This study was designed to investigate the presence and density of domestic mites (DMs) in households with atopic dogs sensitive to these mites (group A; n=20), in households with clinically healthy, nonatopic dogs (group B; n=20) and in households without pets (group C; n=25). Dust samples were vacuum-collected from the owner mattress (all groups) and dog sleeping area (groups A and B) or living room couch (group C) on four consecutive occasions, reflecting the four seasons of the year. DMs were found, at least once, in 19 of 20 (95%) group A, 13 of 20 (65%) group B and 21 of 25 (84%) group C households. DM numbers per gram of dust were 0-159 (median, 8.8), 0-302 (median, 3) and 0-1473 (median, 6.9) for group A, B and C, respectively. Dermatophagoides farinae predominated in all groups, since it was identified in 60% of group A, 40% of group B and 64% of group C households. Dermatophagoides pteronyssinus was found in 45%, 35% and 48% of households, in group A, B and C, respectively. No differences were found between households with (groups A and B) or without dogs (group C). When considering both sampling sites together, frequency of DM recovery was higher in group A than in group B (P=0.044). Also, both mite frequency (P=0.011) and density (P=0.015) in dog sleeping area were higher in group A than in group B. In conclusion, presence and density of DMs is higher in the microenvironment of mite-sensitive dogs with atopic dermatitis than in that of clinically healthy nonatopic dogs.

Temporal changes in the composition of house-dust-mite fauna in Poland

The house dust mites have been shown to produce allergens causing atopic aller- gies in human beings, known in medicine as house-dust-mite allergy or house-dust-mite atopy. A survey of dust samples from different indoor places was made to determine the diversity of the acarofauna, especially potential differences in various rooms and/or in- door microhabitats. Twenty seven years of surveys (1981-2008) in the southern part of Poland formed the basis for this analysis. A total of 1289 house dust samples from dwell- ings from 31 localities were studied including samples from beds (or other bedding ac- commodations), non-carpeted floors, carpets, upholstery furniture, wooden furniture, samples from bedrooms, living-rooms, kitchens and ante-rooms. Moreover, other indoor dust samples were studied: 281 from hospitals, 70 from libraries, 31 from research labora- tories, 30 from drug-stores, 57 from offices and other workplaces. The majority of mites were found in samples from the dwellings, especially in dust from couches, sofas and beds. More than 20 astigmatid mite species were found of which the most abundant and common were pyroglyphids, especially Dermatophagoides farinae H , 1961. Der- matophagoides pteronyssinus (T , 1897) was more abundant per gram of dust only in bed mattresses, whereas D. farinae in samples from the remaining indoor places examined. Highest mite densities per gram of dust were noted in dwellings. In hospitals: D. farinae was more frequent in samples from floors than from patients' beds, whereas D. pteronyssinus was collected more frequently from beds than from floors. Main sources of mites in libraries and drug-stores are shelves, desks, upholstery chairs and carpets, whereas in offices carpeted floors and upholstery furniture. This research, has revealed differences in the occurrence and prevalence of various species of domestic mites be- tween geographical areas and between dwellings within the same geographical area, be- tween particular places within the same dwelling, between the seasons of the year and between years and decades.

Cost and Effectiveness of Community-Wide Integrated Pest Management for German Cockroach, Cockroach Allergen, and Insecticide Use Reduction in Low-Income Housing

Many low-income housing units in the United States continue to have chronic German cockroach, Blattella germanica (L.), infestations and high prevalence of cockroach allergens despite the availability of highly effective cockroach control products. Several studies have demonstrated the greater effectiveness of integrated pest management (IPM) compared with routine chemical interventions in apartment buildings and the benefit of cockroach allergen reduction using IPM. Yet, there has been little information on the cost and benefit of community-wide cockroach IPM, which is critical for voluntary adoption of IPM programs. We evaluated a community-wide IPM program in two low-income apartment complexes in Gary, IN. The program included education of staff and residents, monthly monitoring, and nonchemical (laying sticky traps) and chemical treatment based on monitoring results. One complex of 191 apartments was treated with cockroach gel bait, boric acid dust, and sticky traps by state licensed entomologists from Purdue University (E-IPM group). The other complex of 251 apartments was treated by pest management professionals (PMPs) from a contractor (C-IPM group) following the same protocol as the E-IPM group. Purdue University researchers trained Gary Housing Authority (GHA) staff on cockroach biology and management and cockroach allergen reduction techniques. GHA staff educated all residents in the two complexes on cockroach control and allergen reduction through printed materials, demonstrations, or both. Purdue University entomologists conducted the initial and monthly monitoring in both complexes (laying six sticky traps per apartment and retrieving them the next day) with the assistance from GHA to evaluate program effectiveness, guide insecticide applications, and identify apartments with poor sanitation conditions. Dust samples were collected from kitchen floors of 72 cockroach-infested apartments at the beginning, and again at 6 and 12 mo to evaluate changes in cockroach allergen Bla g 1 concentration. E-IPM resulted in significantly faster cockroach trap count reduction than C-IPM. At 12 mo, the number of cockroach-infested apartments decreased by 74% in both treatment groups. Geometric mean cockroach trap counts decreased from 99.7 at baseline to 0.4 (99.6% reduction) by E-IPM and from 76.0 at baseline to 1.3 (98.3% reduction) by C-IPM. From the first quarter to the fourth quarter, cockroach bait use decreased by 88.5 and 92.7% for E-IPM and C-IPM group, respectively. From month 0 to month 12, geometric mean Bla g 1 concentrations decreased from 27.8 to 2.2 U per gram of dust (U/g) in the E-IPM group and from 5.8 to 2.4 U/g in the C-IPM group. Assuming salary rates at $60/h for PMPs and $19/h for housing authority staff, the mean monthly cockroach management (material and labor expenses) cost was $7.5 USD/apartment for both groups excluding education cost. The cost for subsequent years service is expected to be lower due to reduced cockroach infestations. The effectiveness of both IPM programs was affected by the lack of assistance from housing authority with periodic inspections of the apartments, lack of proper maintenance of the properties, and inadequate cooperation from residents.