Pollution levels of thiobencarb, propanil, and pretilachlor in rice fields of the muda irrigation scheme, Kedah, Malaysia

The purpose of this study was to investigate the potential risk of pretilachlor, thiobencarb, and propanil pollutants in the water system of the rice fields of the Muda area. The study included two areas that used different irrigation systems namely non-recycled (N-RCL) and recycled (RCL) water. Regular water sampling was carried out at the drainage canals during the weeding period from September to October 2006 in the main season of 2006/2007 and April-May 2007 in off season of 2007. The herbicides were extracted by the solid-phase extraction method and identified using a GC-ECD. Results showed that the procedure for identification of the three herbicides was acceptable based on the recovery test values, which ranged from 84.1% to 96.9%. A wide distribution pattern where more than 79% of the water samples contained the herbicide pollutants was observed at both the areas where N-RCL and RCL water was supplied for the two seasons. During September to October 2006, high weedicide residue concentration was observed at the N-RCL area and it ranged from 0.05 to 1.00 μg/L for pretilachlor and propanil and 10-25 μg/L for thiobencarb. In the case of the area with RCL water, the weedicide residue ranged from 1 to 5 μg/L for pretilachlor and propanil and 10-25 μg/L for thiobencarb. The highest residue level reached was 25-50, 50-100, and 100-200 μg/L for pretilachlor, propanil, and thiobencarb, respectively. During April to May 2007, high residue concentration frequently occurred at the area supplied with N-RCL irrigation water and it ranged from 0.05 to 1.00, 10 to 25, and 25 to 50 μg/L for pretilachlor, propanil, and thiobencarb, respectively. The highest residue level reached was 25-50 μg/L for pretilachlor and 100-200 μg/L for propanil and thiobencarb. There was an accelerated increase in the concentration of the herbicide residues, with the maximum levels reached at the early period of weedicide application, followed by a sharp decrease after the rice fields were completely covered with the rice crop. During the main season of 2006/2007, the concentration of propanil residue gradually rose, although that of the other herbicides declined.     

Determination and study on dissipation and residue determination of cyhalofop-butyl and its metabolite using HPLC-MS/MS in a rice ecosystem

Cyhalofop-butyl is an aryloxyphenoxypropionate postemergence herbicide with good control of barnyard grass in rice paddies. In this study, method for the determination of cyhalofop-butyl and its metabolite was developed with high-performance liquid chromatography tandem mass spectrometry. Dissipation and residue levels of cyhalofop-butyl and its metabolite in rice ecosystems were also investigated. Recoveries and relative standard deviations of cyhalofop-butyl and cyhalofop acid in six matrices at three spiking levels ranged from 76.1 to 107.5 % and 1.1 to 8.2 %, respectively. The limit of quantitation (LOQ) of cyhalofop-butyl and cyhalofop acid was 0.01 mg/kg in paddy water, paddy soil, rice plant, rice straw, rice hulls, and husked rice. For field experiments, the results showed that cyhalofop-butyl degraded to cyhalofop acid quickly, and the half-lives of cyhalofop acid in paddy water, paddy soil, and rice plant were 1.01–1.53, 0.88–0.97, and 2.09–2.42 days, respectively. Ultimate residues of cyhalofop-butyl and its metabolite in the rice samples were not detectable or below 0.01 mg/kg at harvest.     

Dissipation and residues of bispyribac-sodium in rice and environment

The dissipation and residues of bispyribac-sodium in rice cropping system were studied. Bispyribac-sodium residues were extracted by a simple analytical method based on QuEChERs and detected by LC-MS/MS. The limit of detection for bispyribac-sodium of this method was 0.375?×?10^?3 ng. The limit of quantification (LOQ) was 5.0 μg/kg for rice plant samples, 2.0 μg/kg for rice hull, 0.2 μg/kg for water, and 0.1 μg/kg for soil and husked rice samples. The average recoveries of bispyribac-sodium ranged from 74.7 to 108 %, with relative standard deviations less than 13 %. The half-lives of bispyribac-sodium in rice plant, water, and soil were in the range of 1.4–5.6 days. More than 90 % of bispyribac-sodium residue dissipated within 5 days. The final residues of bispyribac-sodium in rice were all below LOQ at harvest time.     

Persistence of fipronil and its metabolites in soil under field conditions

Fipronil belongs to phenylpyrazole class of chemical compounds. Degradation of fipronil in sandy loam soil was investigated under field conditions by applying fipronil (Regent 5 % SC) at 50 (T ₁) and 100 g a.i. ha^?1 (T ₂) in field. Samples were drawn periodically in triplicate on 0 (1 h after treatment), 1, 3, 7, 10, 15, 30, 60, and 90 days after treatment and analyzed on GC-ECD system equipped with capillary column. The residues of fipronil in both the doses dissipated in the range of 93.33–100 % in 90 days. Limit of detection (LOD) and limit of determination (LODe/LOQ) were 0.0003 and 0.001 mg kg^?1, respectively. Dissipation followed a biphasic first-order kinetics with half-life values of 10.81 and 9.97 days for fipronil alone and 8.14 and 13.05 days for fipronil along with metabolites in soil at (T ₁) and (T ₂) treatments, respectively.     

Persistence behaviour of imidacloprid and its metabolites in soil under sugarcane

The persistence and metabolism of imidacloprid in soil under sugarcane were studied following application of imidacloprid at 20 and 80 g active ingredient (a.i.) ha^?1. Soil samples were collected at different time intervals (7, 15, 30, 45, 60 and 90 days after application), and the residues of imidacloprid and its metabolites (6-chloronicotinic acid, nitrosimine, imidacloprid-NTG, olefin, urea and 5-hydroxy) were quantified by high-performance liquid chromatography. In soil, the total imidacloprid residues were mainly constituted by the parent compound followed by 6-chloronicotinic acid, nitrosimine and imidacloprid-NTG metabolites. Maximum residues of imidacloprid and its metabolites were 4.29 and 7.81 mg kg^?1 in soil samples collected 7 days after the application of imidacloprid at 20 and 80 g a.i. ha^?1, respectively. At both doses, these residues declined to below the detectable limit in soil after 90 days of application. Olefin, urea and 5-hydroxy metabolites were not detected in soil. Dissipation of total imidacloprid residues did not follow the first-order kinetics with a coefficient of determination value of 0.883 and 0.838 for the recommended dose and four times the recommended dose, respectively. The half-life (T _1/2) value of total imidacloprid was observed to be 10.64 and 10.10 days for the recommended dose and four times the recommended dose, respectively.     

Persistence and Dissipation of Readymix Formulations of Insecticides In/On Okra Fruits

Dissipation behaviour of ready mix polytrin C 44EC (profenophos 40% + cypermethrin 4%) and spark 36EC (triazophos 35%+.deltamethrin 1%) applied at 1 L/ha in okra crop during Kharif in year 2000 was studied at 0, 1, 3, 5 and 7 days after treatment. Dissipation on 7th day was found to be maximum (98.4%) for profenophos followed by triazophos (86.2%), cypermethrin (73.5%) and deltamethrin (55.7%). Half life (t1/2) values for the above insecticides were 1.35, 2.55, 4.11 and 7.60 days, respectively. All the insecticides followed a first order kinetics. Profenophos and triazophos followed a biphasic dissipation pattern with faster dissipation in phase I (0–1 days) and manifesting slower rate of dissipation in phase II (1–7 days).     

Arsenic transformations in terrestrial small mammal food chains from contaminated sites in Canada

Arsenic in terrestrial contaminated sites has the potential to cause harm to residential wildlife. The aim of this study was to determine the arsenic species in wild rodents living in arsenic contaminated habitats, specifically deer mice from Yellowknife, NT and meadow voles from Seal Harbour, NS, along with co-located plants. Methanol : water (1 : 1) extractions were used to optimize the extraction of methylated arsenic(v) species. Total arsenic concentrations were substantially higher in the Yellowknife deer mice (1.7-3.2 μg kg(-1) wet weight in livers) and Seal Harbour meadow voles (0.67-0.97 μg kg(-1) wet weight in livers) living on the contaminated sites with respect to the surrounding background locations (0.12-0.34 μg kg(-1) wet weight in livers). Around 50% of arsenic could be identified in Yellowknife deer mouse tissues, but only <10% was identified in Seal Harbour vole tissues; inorganic arsenic (iii and v) and dimethylarsinic acid were all found. Monomethylarsonic acid was only detected in both the mice and voles living in the contaminated sites. In the Yellowknife food chain, methyl arsenic (v) proportions increased from plants to mouse inner organs, but the trend was not for clear as the Seal Harbour food chain. Seal Harbour voles may be sequestering arsenic in a less mobile form, rather than transforming it.     

The dissipation of ethofenprox in cabbage and soil under open conditions

The dissipation of ethofenprox in cabbage and soil under open conditions was investigated at two primary cabbage-growing regions, Beijing and Kunming in China. Samples were extracted with acetonitrile and determined by ultra-performance liquid chromatography with a single quadrupole detector. Dissipation of ethofenprox from cabbage and soil can be best explained by a first-order decay process. The half-lives of ethofenprox were 1.9 and 2.3 days in cabbage and 20.0 and 13.0 days in soil at Beijing and Kunming, respectively. The concentration of ethofenprox residue was reduced by 90% taking 7 and 60 days in cabbage and soil. Dissipation rates in cabbage and soil at two geographically separated experimental fields differed, suggesting that this was affected by complicated factors, such as local climate and soil characteristics. These data could provide guidance for the proper and safe use of this pesticide on cabbage in China.     

Behaviors of dissolved antimony in the Yangtze River Estuary and its adjacent waters

Antimony is a naturally occurring and cumulatively toxic element. With increasing concern as an inorganic contaminant, research on its environmental behavior is becoming a necessity. However, very little is known about this element. To further understand its biogeochemical behaviors and roles in the ecosystem, the main species of dissolved inorganic antimony (Sb(iii) and Sb(v)) in Yangtze River Estuary and its adjacent waters were determined by hydride generation and atomic fluorescence (HG-AFS) in our study. Results show that in surface water, the concentration for Sb(iii) and Sb(v) were in the range 0.029 μg L(-1)～ 0.736 μg L(-1) and 0.121 μg L(-1)～ 2.567 μg L(-1), with averages of 0.152 μg L(-1) and 0.592 μg L(-1), respectively. While concentrations of Sb(iii) and Sb(v) in the bottom layer were much lower, ranging from 0.023 μg L(-1) to 0.116 μg L(-1) (average of 0.050 μg L(-1)) and from 0.047 μg L(-1) to 0.441 μg L(-1) (average of 0.194 μg L(-1)), respectively. Data analysis further demonstrates that the major processes controlling antimony geochemistry in the area are riverine input, atmospheric deposition, incursion of Taiwan Warm Current, and release from particulate phase. The surface-enrichment and bottom-depletion depth profile reveals it does appear as a mildly scavenged element but is less like arsenic than previously believed. Sb(v) was the predominant speciation in aquatic environment of our research, and Sb(iii) was a minor constituent of the total antimony. Regarding the adsorption-desorption process onto SPM, Sb(iii) has a higher affinity to particulate phase than Sb(v). Furthermore, the significant correlation between antimony and nutrients indicates it is an element with great biological potential, which is also an important behavior for antimony.     

Dissipation of Endosulfan and Dichlorvos Residues In/On Cauliflower Curds

Dissipation behaviour of endosulfan and dichlorvos in/on cauliflower, variety Snowball-16, was studied during rabi season (Sep.–March) 2003–2004. Endosulfan and dichlorvos were sprayed @ 350 and 110g a.i. with 115 g a.i., respectively, 80 days after transplanting. Samples were taken at the interval of 0 (1h after spray), 3, 5, 7, and 10 days after spray (DAS) in triplicate and residues were estimated on GC-ECD system equipped with capillary column. The initial deposits of 3.452 and 0.295μgg⁻¹ of endosulfan and dichlorvos dissipated to 0.084 (97.56%) and 0.009 (96.95%), respectively after 10 DAS. Residues of endosulfan reached below maximum residue limit of 2μgg⁻¹ one day after spray and of dichlorvos were below MRL value of 0.5μgg⁻¹ even on 0 day. Dissipation pattern followed first order kinetics for both the insecticides with half life periods of 1.81 and 2.08 days for endosulfan and dichlorvos, respectively.     

The impact of a rice based diet on urinary arsenic

Rice is elevated in arsenic (As) compared to other staple grains. The Bangladeshi community living in the United Kingdom (UK) has a ca. 30-fold higher consumption of rice than white Caucasians. In order to assess the impact of this difference in rice consumption, urinary arsenicals of 49 volunteers in the UK (Bangladeshi n = 37; white Caucasians n = 12) were monitored along with dietary habits. Total urinary arsenic (As(t)) and speciation analysis for dimethylarsinic acid (DMA), monomethylarsonic acid (MA) and inorganic arsenic (iAs) was conducted. Although no significant difference was found for As(t) (median: Bangladeshis 28.4 μg L(-1)) and white Caucasians (20.6 μg L(-1)), the sum of medians of DMA, MA and iAs for the Bangladeshi group was found to be over 3-fold higher (17.9 μg L(-1)) than for the Caucasians (3.50 μg L(-1)). Urinary DMA was significantly higher (p < 0.001) in the UK Bangladeshis (median: 16.9 μg DMA L(-1)) than in the white Caucasians (3.16 μg DMA L(-1)) as well as iAs (p < 0.001) with a median of 0.630 μg iAs L(-1) for Bangladeshi and 0.250 μg iAs L(-1) for Caucasians. Cationic compounds were significantly lower in the Bangladeshis (2.93 μg L(-1)) than in Caucasians (14.9 μg L(-1)). The higher DMA and iAs levels in the Bangladeshis are mainly the result of higher rice consumption: arsenic is speciated in rice as both iAs and DMA, and iAs can be metabolized, through MA, to DMA by humans. This study shows that a higher dietary intake of DMA alters the DMA/MA ratio in urine. Consequently, DMA/MA ratio as an indication of methylation capacity in populations consuming large quantities of rice should be applied with caution since variation in the quantity and type of rice eaten may alter this ratio.     

Dissipation kinetics of tetraconazole in three types of soil and water under laboratory condition

Laboratory experiment was conducted to understand the persistence behavior of tetraconazole in three soils of West Bengal (alluvial, red lateritic, and coastal saline) and also in water maintained at three different pH (4.0, 7.0, and 9.2) conditions. Processed soil samples (100 g) were spiked at two treatment doses: 2.5 μg/g (T₁) and 5.0 μg/g (T₂). Double distilled buffered water (200 ml) was spiked at two treatment doses: 1.0 μg/ml (T₁) and 2.00 μg/ml (T₂). The tetraconazole dissipation followed first-order reaction kinetics and the residual half-life (T _1/2) values in soil were found to be in the range of 66.9–77.2 days for T₁ and 73.4–86.0 days for T₂. The persistence increased in the order red lateritic > new alluvial > coastal saline. Interestingly, the red lateritic soil exhibited the lowest pH (5.56) and organic carbon (0.52 %) content as compared to other two soils. However, the dissipation of tetraconazole in case of water was not pH dependant. The T _1/2 values in water were in the range of 94 to 125 days. The study indicated the persistent nature of tetraconazole in soil and water.     

Persistence of dicofol residues in cotton lint seed, and soil

A supervised field trial was conducted at the CCS Haryana Agricultural University, Hisar to assess the residues of dicofol on cotton, during Kharif season, 2008. Dicofol (Kelthane 18.5EC) was applied at 500 g a.i./ha (T(1)) and 1,000 g a.i./ha T(2)) after 105 days of sowing of cotton crop (Varity Cotton/H-1226). Soil samples were collected on 0 (1 h after treatment), 3, 7, 10, 15, 30, and 60 days after spray and cotton samples were collected at harvest. Samples were processed and residues were quantified by GC-ECD system equipped with capillary column. Limit of detection and limit of quantification (LOQ) were 0.001 and 0.010 mg kg(?-1), respectively, for soil and LOQ for cotton lint and seed was 0.020 mg kg(?-1). Initial residues of 0.588 and 1.182 mg kg(?-1) in soil reached below detectable level (BDL) of 0.010 mg kg(?-1) in T(1) and to the level of BDL (0.010 mg kg(?-1)) in T(2) at harvest (60 days after treatment). In 60 days, residues dissipated almost completely (100 and >99%) in both the treatments. Half-life period was calculated as 8.57 days at single dose and 8.69 days at double dose in soil. Residues of dicofol were detected in cotton lint to the levels of 0.292 and 0.653 mg kg(?-1) and in seed 0.051 and 0.090 mg kg(?-1) in T(1) and T(2) doses, respectively at harvest. Residues in cotton seed were below MRL value of 0.01 mg kg(?-1) in both the doses.     

Long-term changes of heavy metal and sulphur concentrations in ecosystems of the Taymyr Peninsula (Russian Federation) North of the Norilsk Industrial Complex

The Norilsk industrial ore smelting complex (Taymyr Peninsula, Russian Federation) has significantly impacted many components of local terrestrial and aquatic environments. Whether it has had a major impact on the wider Russian Arctic remains controversial as studies are scarce. From 1986 to 2004, data on heavy metal (Cu, Ni, Zn, Hg, Cd and Hg) concentrations in fish (burbot), moss, lichens, periphyton, hydric soils and snow in and around Norilsk and the most northern parts of the Taymyr Peninsula were analysed. Very high concentrations of Cu (203 μg L?1 ± 51 μg L?1) and Ni (113 μg L?1 ± 15 μg L?1) were found in the water of the Schuchya River close to Norilsk. Heavy metal concentrations in burbot liver were highest in Lake Pyasino near Norilsk compared to other study regions that were >100 km distant. From 1989-1996, Cu (121 μg L?1 ± 39 μg L?1 SD), Zn (150 μg L?1) ± 70 μg L?1) and Ni (149 μg L?1 ± 72 μg L?1) snow concentrations were greatest in Norilsk, but were low elsewhere. By 2004, these concentrations had dropped significantly, especially for Cu-74 μg L?1 (±18.7 μg L?1 SD), Zn-81.7 μg L?1 (± 31.3 μg L?1 SD) and Ni-80 μg L?1(±18.0 μg L?1 SD). Norilsk and its surroundings are subject to heavy pollution from the Norilsk metallurgical industry but these are absent from the greater Arctic region due to the prevailing winds and the Byrranga Mountains. Pollution abatement measures have been made so further investigations are necessary in order to assess their efficiency.     

Distribution behavior and carcinogenic level of some polycyclic aromatic hydrocarbons in roadside soil at major traffic intercepts within a developing city of India

A study of polycyclic aromatic hydrocarbons (PAHs) pollution in roadside soil was conducted at a developing city locations of Jalandhar (Punjab), India in winter season to ascertain the contamination levels and their distribution behavior in roadside soil. PAHs concentration level of ten locations was measured at 1, 2, and 3 m distances from roadside soil covering all the major traffic intercepts within a city. Samples were extracted in acetone and dichloromethane (1:1) using soxhlet extraction. The extracts were filtered on a silica gel micro column to remove impurities and eluate was subjected to GC-FID. The total average PAHs concentration (city average) was found to be 4.04 μg g(-1), whereas the concentration of 16 individual PAHs was found to vary between 0.008 and 28.4 μg g(-1). The average concentration of noncarcinogenic and carcinogenic PAHs in all the samples was 2.17 and 6.41 μg g(-1) (ratio 1:2.95). The concentration of five ringed PAHs was found to be 45% to 60%, whereas two ringed PAHs were found to be in the range from 0.28% to 0.56% in all most all locations. The average highest PAHs concentration for any individual location was found as 12.23 μg g(-1) at DAV Chowk at 1 m distance and minimum concentration was 0.98 μg g(-1) at Maqsuda Chowk at 1 m distance from roadside. DiB (ah) A was the individual PAHs found in highest concentration in all the intercepts ranging between 1.26 and 28 μg g(-1). At most of the city intercepts, total carcinogenic PAHs concentration was found to range from 60% to 80% in comparison to noncarcinogenic PAHs (20%-40%) at most of the intercepts. The pollution level our study was compared with other cities of India/worldwide.     

Determination of imazosulfuron persistence in rice crop and soil

Imazosulfuron is a new post-emergence sulfonylurea herbicide. It is highly active at low application rates to control annual and perennial broad-leaf weeds and sedges in rice. There is increasing concerned about the persistence of pesticide residues in soils, crop produce and subsequent contamination of groundwater. Thus persistence of imazosulfuron residues under field condition was evaluated. Imazosulfuron was applied at 30, 40, 50 and 60 a. i. g ha ⁻¹ rates, 4 days after transplanting of rice as post-emergence herbicide. Soil and plant samples treated with imazosulfuron were collected at 60, 90 and 120 days after herbicide application and analyzed for residues. Rice grains and straw samples were sampled at harvest (120 days). Residues of imazosulfuron in soil were not found after 90 and 120 DAS (days after spraying). Rice grains contained 0.006, 0.009 μg g⁻¹ residues at 50 and 60 g ha ⁻¹ application rates. 0.009 and 0.039 μg g⁻¹ residues of imazosulfuron were detected at 50 and 60 g/ha rates respectively in rice straw. Residues of imazosulfuron were not detected applied at 30 and 40 g ha⁻¹ in rice grains and straw, respectively and can be safely applied to the transplanted rice.     

高效液相色谱-原子荧光光谱联用分析土壤中形态砷

采用高效液相色谱(HPLC)-原子荧光光谱(AFS)联用技术分析土壤中亚砷酸盐[As(Ⅲ)]、二甲基砷(DMA)、一甲基砷(MMA)和砷酸盐[As(Ⅴ)]等4种形态砷,以磷酸为提取剂、抗坏血酸为还原剂,优化了水浴提取条件。As(Ⅲ)、DMA、MMA和As(Ⅴ)在7 min之内实现了完全分离,在1.00μg/L～100μg/L范围内线性良好,实验室检出限分别为0.25μg/L、0.36μg/L、0.39μg/L和0.51μg/L,土壤标准样品平行测定的RSD≤7.4%,加标回收率为79.5%～95.0%,提取率为74.6%～90.4%。     

Community exposure to arsenic in the Mekong river delta, Southern Vietnam

We examined the daily inorganic arsenic (i-As) intake from drinking water and rice in 45 households (75 individuals) in the An Giang province, Southern Vietnam. The daily i-As intake ranged from 28-102 μg d(-1), equivalent to the daily dose of 0.6-1.9 μg d(-1) kg((body wt))(-1). Increased As concentrations were observed in human hair in the study location. Approximately 67% (n = 44), 42% (n = 28), and 15% (n = 10) of the hair samples had As levels exceeding 1, 3, and 10 μg g(-1), respectively. The total As concentrations in female and male hair correlated well with the total daily i-As intake. Measurement of As concentrations in the hair of people who were consuming or had previously consumed As from contaminated sources may help predict the onset of negative health effects. We suggested an application of the Bayes's theorem to calculate the probability that an individual in a population will acquire a negative health effect, given that the concentration of arsenic in the subject's hair has been determined.     

Persistence and effect of processing on reduction of fipronil and its metabolites in chilli pepper (Capsicum annum L.) fruits

A single laboratory UPLC-MS/MS method was developed and validated for the estimation of fipronil and its metabolites in fresh and dry chilli pepper fruits. Dissipation of fipronil on chilli fruits was studied following the application of fipronil (Jump 80 WG) at 40 and 80 g active ingredient (a.i.) ha^?1 in the fruiting stage of the crop. The initial deposits of total fipronil on fresh chilli fruits at single and double dose application were 0.69 and 1.43 μg g^?1, respectively, and were dissipated to below quantitation level at 27 days after application. The half-life of fipronil at single and double dose in fresh chilli pepper was 4.22 and 4.32 days and the waiting period was 25.9 and 30.6 days, respectively. Processing factor due to sun drying was calculated by measuring fipronil residues in dry chilli fruits, and it ranged from 2.96 to 3.50 during 0 to 21st day after application. Among the metabolites of fipronil, fipronil desulfenyl and fipronil sulfone had maximum residues in fresh and dried chilli, respectively, followed by fipronil sulfide. Dipping in solutions of tamarind, turmeric, vinegar and slaked lime and wet scrubbing could remove more than 90 % of fipronil residues in fruits.     

Assessment of public exposure to naturally occurring radioactive materials from mining and mineral processing activities of Tarkwa Goldmine in Ghana

Studies have been carried out in a Goldmine in Ghana to determine the exposure of the public to naturally occurring radioactive materials from processing of gold ore. Direct gamma spectrometry and neutron activation analysis techniques were used to analyse soil, rock, water and dust samples from the mining environment. The mean activity concentrations measured for (238)U, (232)Th and (40)K in the soil/rock samples were 15.2, 26.9 and 157.1 Bq kg(?-?1), respectively. For the water samples, the mean activity concentrations were 0.54 and 0.41 Bq l(?-?1)) and 7.76 Bq l(?-?1) for (226)Ra, (232)Th and (40)K, respectively. The mean activity concentrations measured in the dust samples were 4.90 and 2.75 μBq m(?-?3) for (238)U and (232)Th, respectively. The total annual effective dose to the public was estimated to be 0.69 mSv. The results in this study compared well with typical world average values. The results indicate an insignificant exposure of the public from the activities of the Goldmine.