Evaluation of atmospheric dust deposition rates and their mineral characterization in copper and iron mining areas, Singhbhum, India

ABSTRACT

Atmospheric dust can play a very important role in the polluted atmosphere. This has a direct impact on human health, global warming, climate change, visibility, precipitation, cloud formation, and so on. To evaluate the atmospheric dustfall rate and their mineralogical aspects, three separate sites were selected, namely mining, suburban, and control for dust sampling. Dustfall samples were collected at monthly intervals from copper and iron mining areas, in Singhbhum, India. The average atmospheric dustfall rate varied from 7.51 to 28.58 g/m²/month, and 7.40 to 26.37 g/m²/month during the summer and winter seasons, respectively, in the copper mining areas. At the same time, an average atmospheric dustfall rate varied from 7.23 to 76.99 g/m²/month during summer season and 6.48 to73.92 g/m²/month during the winter season in the iron mining area. The major minerals identified by X-ray diffraction (XRD) analysis of dustfall samples from copper mining area were quartz, kaolinite, pyrite, albite, and magnesio hornblende. However, in the case of iron mining area, the major minerals found were quartz, cristobalite, hematite, magnetite, biotite, albite, ilmenete, pyrite, rutile, and dolomite. Overall, the intensity of dust pollution is greater in the vicinity of mining and industrial sites of the copper and iron mining areas.

Implications: The study has been conducted in the copper and iron mining areas of East and West Singhbhum districts of Jharkhand state, respectively. The aim of the present study was twofold, namely, (i) to evaluate the dustfall rates (ii) and to characterize the mineralogy of atmospheric dust. East and West Singhbhum are the significantly industrialized areas of India known for the mining of copper and iron ores, steel production, power generation, and other related activities. In order to improve local people’s living conditions, there is an urgent need for baseline data of dust pollution and its general characteristics based on scientific disclosures to allow policy recommendations and their implementation. Therefore, the study falls within the scope of the journal. The atmospheric dustfall rates were found to be higher during the summer season due to increased dispersion caused by the high wind speed during the summer season. During the winter season, lower rates were observed due to monsoonal rainfall washout and higher relative humidity, which reduces dust resuspension. However, the present study considered the extent of dustfall rates and their mineral characteristics. An immediate need arises to regularly monitor the dust pollution and to implement suitable dust control system like wet dust suppression and airborne dusts capture for dust abatement.

Introduction

Atmospheric air is necessary for humans and other living beings to exist. Major sources of air pollution can be broadly categorized into both anthropogenic and natural emissions. Natural emissions are not yet under human control, however technologies are available for mitigating air pollution through human emissions. Industries (e.g., thermal power plants, refineries, steel plants, open cast mines, bricks kiln) and vehicle and household emissions are the largest anthropogenic sources of air pollution. Mining is a significant source of emissions from dust among the numerous sources of air pollution (Ghose and Majee 2000). Factors such as vegetation cover, precipitation, wind strength, and soil moisture regulate the amount of dust in the air (Ta et al. 2004). Dust consists primarily of loose particles, which are caused by soil erosion, road transport, manufacturing, volcanic eruptions, and so on. Atmospheric mineral dust plays a key role in controlling various atmospheric processes such as cloud dynamics, precipitation, and atmospheric chemistry (Andreae and Crutzen 1997; Kulshrestha et al. 2009). Mineral dust has a major effect on biodiversity and climate and biogeochemical cycles by depositing minerals and organic materials into the terrestrial ecosystem (Jickells, An, and Andersen 2005; Lawrence and Neff 2009).

Mining and industry are using large-scale mechanizations and releasing massive amounts of dust and gasses that adversely affect human health (Dhar 1994). Different mining processes that release enormous quantity of dust, particularly in open cast mining, include removal of topsoil, removal of overburden, blasting and drilling operations, reduction in size, transportation of minerals and minerals on roads, mineral handling of plants, and so on. In both quantitative and qualitative terms, the rate of dustfall and its chemical constituents are important to investigate the dust pollution of a particular area (Harrison and Perry 1986). Managing copper mining dust is important because it can affect local and national air quality, adversely affect local infrastructure, and pose a public health threat. An average annual dustfall of 96.2 ± 3.6 ton/km²/month was recorded at a subtropical opencast coal mine, Bina, India (Pandey et al. 2008). The maximum deposition of dust 278.9 ton/km²/month occurred during summer season, and during the rainy season deposition was found lowest at 16.2 ton/km² per month. Emission inventory analysis was conducted during (2015–2016) to assess the worst possible concentration of particulate matter in the Singhbhum area due to mining activities (CSIR-CIMFR 2017). The baseline average 24 hours PM10 and PM2.5 concentrations ranged from 60.1 to 326.89 μg/m³ and 34.0–156.02 μg/m³, respectively. Concentrations of PM10 and PM2.5 were found to be higher than the National Ambient Air Quality Standards (NAAQS) in most of the Saranda region’s working mining areas (CSIR-Central Institute of Mining and Fuel Research 2017).

In the current scenario, concentrations of PM10 and PM2.5 at most monitoring locations in the Singhbhum area are higher than the NAAQS (Chaulya et al. 2019). Therefore, a comprehensive study on the monitoring of atmospheric dustfall was carried out to know the present status of air quality in the area. In order to improve local people’s living conditions, there is an urgent need for baseline data of dust pollution and its general characteristics based on scientific disclosures to allow policy recommendations and their implementation. The aim of the present study was twofold, namely (i) to evaluate the dustfall rate (ii) and to characterize the mineralogy of atmospheric dustfall.

Study area

The study was conducted in the Jharkhand state’s copper and iron mining areas of East and West Singhbhum districts, respectively. It comprises the significant industrialized areas of India known for mining of ores, steel production, power generation, and other related activities.

Copper mining area is situated from latitude 22°13′N to 22°55′N and longitude 86°05′E to 86°42′E in the East Singhbhum district. The district covers an area of about 3,533 km². Approximately 53% of the district’s total area is covered by residual mountains and hills composed of granite, gneiss, schist, and basalt rocks. It is a part of the Dharwarian-era Chota Nagpur plateau of igneous, sedimentary, and metamorphosed rocks. The Dalma range is the main hill covered by dense forest extending from west to east. The Subarnarekha River flows from west to south-east direction. The district is rich in mineral resources, and iron, copper, uranium, gold, and kyanite are the main minerals of the district.

The iron mining area is located in the Southern part of the west Singhbhum district of Jharkhand State and spreads over 22°00ʹN to 22°50ʹN latitude and 85°00ʹE 86°00ʹE longitudes. The district has an area of 5,351 km². The district is full of mountain slopes alternating with valleys, steep mountains, and deep forests. The district contains one of the best forests of Sal, and the forest area of Saranda (seven hundred hills) is known all over the world. Some of the important rivers flowing in the districts are Koel, Kharkhai, Sanjai, Raro, and Baitarini. The greater part of West Singhbhum district is covered by the iron-ore series. The major minerals that are found in the district consist of chromites, magnetite, manganese, kainite, lime stone, iron ore, asbestos, and soap-stone.

Materials and methods

Sampling of atmospheric dustfall

Atmospheric dustfall sampling sites were selected according to the land use plan and meteorological condition of the study areas. Gravity techniques are used to collect free fall dust particulates in the air (Lodge 1988). Dustfall samples were collected as per the guideline provided by the Indian standard methods for measurement of Air pollution, Part-1, Dustfall (IS 5182 part-1, 2006) and Standard method for collection and analysis of dustfall (Settleable particulates (ASTM 2004). The dustfall sampling device was assembled with high density open-mouthed plastic bucket fitted with iron tripod stand. Dustfall collection assemblies were mounted on 1.2 m high iron tripods to avoid the collection of dust picked up by wind eddies.They were exposed to the atmosphere for 3 months during summer (March- May, 2018) and 3 months during winter (October-December, 2018). Dust samples were collected at the end of each month. The buckets were inspected periodically for water loss and then replenished. The mass of the dust deposits per unit area of bucket water surface area is determined after evaporating the water to dryness and weighing. The result is reported in g/m²/month or tonnes/km²/month. Based on the prevailing meteorological conditions and anthropogenic activities, the entire copper mining area has been divided into 5 sites (ED-1: Dalma as a control site, ED-2: Adityapur, ED-3: Ghatsila, ED-4: Benasol, and ED-5: Baharagora), and the iron mining area has also been divided into 5 sites (WD-1: Chaibasa as a control site, WD-2: Noamundi, WD-3: Barajamda, WD-4: Hathigate, and WD-5: Kiriburu). The monitoring sites of atmospheric dustfall of copper and iron mining area are provided in Figure 1. The control sites Dalma (ED-1) and Chaibasa (WD-1) were selected as they were far from the mining and industrial activities. Dalma is located at hilltop on Dalma wildlife sanctuary and nearly 20 Km away from Jamshedpur city and 15 Km from national highway 33. It has been selected as the control site. Chaibasa is selected as the control site for iron mining area since the site is free from any mining and industrial activity.

Figure 1. Location map of the study area

Analytical procedure for atmospheric dustfall

Dissolved and undissolved matter

The collected liquid was filtered with Whatman No. 42 filter paper. The residue on the filter was dried at 105°C for 3 h, allowed to cool in a desiccator to constant weight and then weighed. The weight represented the total amount of undissolved matter. The filtrate was transferred into a beaker and concentrated to no more than 100 ml by evaporation. The concentrate was transferred to a crucible to further concentrate. When the concentration had almost solidified, the evaporating dish was dried at 105°C for 2 h, allowed to cool in a desiccator, and weighed. The quantity of dissolved matter in the collected liquid was calculated from the weight difference against the evaporating dish.

Total dustfall matter

The calculation for the total dustfall matter was made by making summation of the weight of water soluble matter and water insoluble matters of individual sample.

Total dustfall matter = (Weight of dissolved matter + weight of undissolved matter).

Dustfall rate: The total dustfall quantity (W) is the sum of the amount of dissolved and undissolved matter, and the dustfall quantity is calculated from w using the following equation (Kikuo 1977):

$Dustfallrate=\frac{1.273\times \mathrm{W}\times 30\times {10}^4\hspace{0.17em}\left(g/m^2/30\hspace{0.17em}days\right)}{{\mathrm{D}}^2\times \mathrm{n}},$

where W is the total dust in the collecting jar, D the diameter of Bucket (cm), and n the number of days of collection.

Mineralogical evaluation

Mineralogy of the dustfall samples were accomplished using a Rigaku (Japan) make Ultima IV, X-Ray Diffractometer (XRD) with theta-theta geometry and fitted with solid state detector. Dust samples were sieved through 200 mesh size for XRD analysis. Each sample was kept on a glass sample holder, which was spun at 30 revolutions per minute and scanned with CuKα radiation from 5 to 700 2 θ values (Kumari et al. 2016). Samples were analyzed using smooth XRD background, 45 kV acceleration voltages, 40 mA electric tube flow, 2°/minute scanning speed, and 0.02° scanning with 5°−50° range (range of 2 θ) (Queralt et al. 2001). A graph between intensity (counts) and position (2 θ values) has been obtained as a result. Minerals were identified from diffractogram by tallying the d-spacing values with that of mineral in the standard library given in the American Society for Testing and Materials (ASTM) powder diffraction data file and International Centre for Diffraction Data (ICCD) mineral library was used for mineral identification.

Results and discussion

Seasonal variation of dust deposition rates in the copper mining area

Average atmospheric dustfall rate varied from 7.51–28.58 g/m²/month and 7.40–26.37 g/m²/month with an average dustfall rates 20.45 g/m²/month and 15.98 g/m²/month were recorded during the summer and winter season, respectively, in the mining areas of East Singhbhum. The highest average dustfall rate was measured 28.58 ± 4.25 g/m²/month at Adityapur (ED-2) during summer season. The dustfall sampling site, ED-2 is in close proximity to the Tata steel plant and also a large number of small scale industries, followed by 26.59 ± 1.15 g/m²/month at Benasol and 22.37 ± 1.20 g/m²/month at Ghatsila. Both sites are in close vicinity of copper mining, copper mill, and other industrial activities. The result showed that Adityapur, Benasol, Ghatsila, and Baharagora receive a dust load of 26.37 ± 1.47, 19.81 ± 0.89, 14.6 ± 1.11, and 11.72 ± 1.24 g/m²/month, respectively, during winter season. The lowest dustfall rate was observed at Dalma (7.40 ± 0.50 g/m²/month) during the winter season, which is free from any anthropogenic activities and have been taken as the control site (Table 1 & Figure 2a).

Table 1. Dustfall rates (g/m²/month) of Copper and Iron mining area

		Copper mining area (N = 30)				Iron mining area (N = 30)
Sampling Sites	Seasons	Minimum	Maximum	Average	Sampling Sites	Minimum	Maximum	Average
Dalma (Control) ED-1	S	6.75	7.97	7.51	Chaibasa (Control) WD-1	6.56	7.85	7.23
	W	6.85	7.84	7.40		6.13	6.78	6.48
Adityapur ED-2	S	23.71	31.50	28.58	Noamundi WD-2	24.95	26.69	25.71
	W	24.69	27.45	26.37		14.26	25.67	21.19
Ghatsila ED-3	S	21.09	23.48	22.37	Barajamda WD-3	48.96	60.83	55.47
	W	13.47	15.68	14.60		50.35	54.84	52.62
Benasol ED-4	S	25.47	27.76	26.59	Hathigate WD-4	75.82	78.58	76.99
	W	18.95	20.73	19.81		73.15	74.64	73.92
Baharagora ED-5	S	15.21	19.67	17.22	Kiriburu WD-5	16.87	26.85	20.47
	W	10.47	12.94	11.72		17.65	19.44	18.38

Note. S = summer; W = winter.

Figure 2. (a) Dustfall rates of copper mining area. (b) Meteorological parameters of copper mining area

The difference in dustfall rates between different sampling sites in summer and winter seasons can be explained by the difference in meteorological conditions (see Figure 2b). The study area witnesses high temperature, low relative humidity, and high wind speed during the summers, and the inverse during the winters. During the sampling period, the average temperature, relative humidity, and wind speed of the study area were 32.0°C, 34.3%, and 8.8 Km/h, respectively, for summer, and 26.3°C, 48.7%, and 5.7 Km/h, respectively, for winter. These meteorological conditions can be attributed for the higher rates of free fall dust during summer as compared to winter. The high wind strength at higher temperature range and low relative humidity in the summer months is responsible for the erosion of the earth crust resulting in increased levels of coarse particles that get settled down due to gravity (Moja and Mnisi 2013). Open soil and land are mainly responsible for high atmospheric particulate matter in the Indian region (Khemani et al. 1989; Kulshrestha et al. 2009; Kumar, Verma, and Kulshrestha 2014).

Seasonal variation of dust deposition rates in the iron mining area

The result showed that Hathi gate and Barajamda, which are under the influence of heavy traffic and iron ore mining activities, receive higher amount of dust load 76.99 ± 1.43 and 55.47 ± 6.02 g/m²/month, respectively, during the summer season. The lowest dustfall was found to be at Chaibasa, which was taken as the control site where the dustfall rate ranged between 6.56–7.85 g/m²/month with an average dustfall rate of 7.23 ± 0.65 g/m²/month during the summer season. The average atmospheric dustfall rate varied from 7.23– 76.99 g/m²/month (average 37.17 g/m²/month) and 6.48–73.92 g/m²/month (average 34.52 g/m²/month) during the summer and winter seasons, respectively, in the mining area of West Singhbhum. The highest dustfall rate was measured at 73.92 ± 0.75 g/m²/month at Hathi gate near the Gua iron ore mines adjoining other private iron mines, followed by 52.62 ± 2.25 g/m²/month at Barajamda during winter season; the lowest dustfall rate was observed to be 6.48 ± 0.33 g/m²/month at Chaibasa during the winter season (Table1 & Figure 3a). In general, a higher dustfall rate in summer means higher abundance of crust matter due to lower humidity levels that dries out the accumulated dust, which makes it easier for the dust to disperse throughout the atmosphere, as explained earlier. During the sampling period, the average temperature, average relative humidity, and average wind speed of the West Singhbhum was 31.7°C, 32.7% and 8.4 Km/h, respectively, for summer, and 24.7°C, 55% and 5.6 Km/h, respectively, for winter (Figure 3b). Turbulent winds favor air convection leading to the resuspension of local dust, soil erosion, and long range dust transportation from dry areas. Meteorological factors such as humidity, solar radiation, and temperature lead to the formation of atmospheric dust (Mondal et al. 2010). The higher wind speed in summers may blow the earth crust and resuspended dust from open grounds and agricultural fields. The dust collected in the study area is not only affected by nearby mining activities, but also by the regional, local, and even domestic activities. Unpaved and dusty streets in mining and industrial area are the main source of dust in the atmosphere.

Figure 3. (a) Dustfall rates of Iron mining area. (b)Meteorological parameters of iron mining area

Table 2 reflects a comparison of the present study’s dustfall levels with other research conducted in urban areas of some global cities. The table suggests that there is considerable difference in the dustfall rates of the present study as compared to other studies. This can be attributed to differences in geographic locations, traffic compositions, and the type of industries that run across the area (Table 2). Seasonal variation in dustfall rate was found to be varying significantly across locations as well as seasons, as summarized in Figures 2a and Figures 3a. Currently, there are no standards of dustfall prescribed by statutory bodies in India. However, National Environment Engineering Research Institute (NEERI), Nagpur, India, has developed a standard for research study in residential areas as 10 t/km²/month (which corresponds to 10 g/m²/month). Also, it was found that the Egyptian law 470/1970 prescribes dustfall standard of 14 g/m²/month for industrial areas, and South African National Standard (2005) prescribes 18 and 36 g/m²/month for residential and industrial area (Table 3). Compared with all the standards indicated above, the dustfall rate in the study areas found to be significantly higher to the standards set for the different countries including the standard set by NEERI, Nagpur.

Table 2. Comparison of dust fall rate of Copper and Iron mining area with other cities in the world

Study area	Country	Average Dustfall rate (g/m^2/month)	References
East Singhbhum Summer Winter	India	20.45 15.98	Present study
West Singhnbhum Summer Winter	India	37.17 34.52
Kharagpur	India	13.09	Rani, Sastry, and Dey 2019
Singrauli, 2011	India	37.56	Dubey, Singh, and Singh 2013
Singrauli, 2012	India	41.32	Dubey, Singh, and Singh 2013
East Delhi	India	9.31	Sharma, Singh, and Kulshrestha 2017
Delhi, India	India	2.90	Kumar, Verma, and Kulshrestha 2014
New Delhi	India	2.94	Kumar, Verma, and Kulshrestha 2014
Commercial area, Jharia Coalfield	India	13.85	Rout et al. 2014
Residential area, Jharia Coalfield	India	9.56	Rout et al. 2014
Coal mining area, Bina	India	96.2	Pandey et al. 2008
Chennai City	India	34.00	Sultana, Sakunthala, and Jayaraj 2008
Non- India Studies
Malaysia	Malaysia	3.99	Alahmr et al., 2012
Guagzhou	China	3.73	Zhao et al. 2010
South Island	New Zealand	2.20	Marx and McGowan 2005
Namoi Valley	Australia	2.58	Cattle, McTainsh, and Wagner 2002
Coast Mountain, BC	Canada	0.89	Owens and Slaymaker 1997
French Alp	France	0.17	De Angelis and Gaudichet 1991
Elazig cement plant	Turkey	36.37	Arslan and Boybay 1990
Miami, Florida	USA	0.02	Prospero, Nees, and Uematsu 1987
Northern Nigeria	Africa	13.06	McTainsh and Walker 1982

Table 3. Threshold limit values of dustfall rate (Narayan et al. 1994)

Sl No.	Label	Dust fall rate, D g/m^2/month	Action taken
1	Residential	D < 18	Permissible for residential and light commercial.
2	Industrial	24 < D < 36	Permissible for heavy commercial and industrial.
3	Action	36 < D < 72	Requires investigation and remediation if two sequential months lie in this band or more than three occur in a year.
4	Alert	72 < D	Immediate action and remediation required following the first incidence of dust fall rate being exceeded, incident report to be submitted to relevant authority.

Mineral characteristics of dustfall in copper mining area

Atmospheric falling dust has different particle morphology and mineralogical composition by source (Chen and Xu 2003; Gomez et al. 2004; Zhang et al. 2009). Atmospheric dustfall has a complex mineralogical composition, based on its deposition of both natural and anthropogenic sources of atmospheric aerosols. Mineralogical dust composition may be due to geographical characteristics of the pattern of soil, land use and land cover, road length, and vehicle flow. The geology of the research area consists primarily of sand, silt, and clay with unoxidized sand and quartzite. Thus quartz predominance in dustfall samples is justified.

Mineralogical features of atmospheric dustfall samples were obtained through XRD analysis. Quartz, albite, pyrite, and chalcopyrite are the main minerals contained in the dust samples. Dust rich mainly in quartz, carbonates, and feldspar is usually continental and comes mainly from local sources (Pye 1987). The XRD image of dust samples of copper mining area is depicted in Figure 4a. Kaolinite, pyrite, albite, and magnesiohornblende were found to dominate dusts from the Jharia mining area in eastern Jharkhand (Rout et al. 2014). Table 4 displays the mineralogical composition of dust samples with its chemical formula.

Table 4. Percentage of occurrence of mineralogical compositions of atmospheric dustfall in copper and iron mining area (+ = present, − = absent)

		Dustfall Samples of Copper mining area					Dustfall Samples of Iron mining area
Minerals	Chemical Formula	ED-1	ED-2	ED-3	ED-4	ED-5	WD-1	WD-2	WD-3	WD-4	WD-5
Quartz	SiO2	+	+	+	+	+	+	+	+	+	+
Muscovite	KAl2(Si3Al)O10(OH,F)2	-	+		+	-	−	−	−	−	−
Chlorite	(Mg5Al)(AlSi3)O10(OH)8	-	-	+	-	-	−	−	−	−	−
Calcite	CaCO3	-	-	-	-	-	+	−	−	−	−
Albite (Low)	NaAlSi3O8	-	+	+	+	-	−	−	−	−	−
Dolomite	CaMg(CO3)2	+	-	+	-	-	+	−	−	+	−
Actinolite	Ca2(Mg,Fe^++)5Si8O22(OH)2	-	-	-	-	-	−	−	−	−	−
Oligoclase	(Na,Ca)(Si,Al)4O8	-	-	-	-	-	−	−	−	−	−
Gypsum	CaSO4⋅2(H2O)	+	-	-	-	-	−	−	−	−	−
Albite	Na Al Si3O8	-	-	-	-	-	−	+	+	+	−
Ilite	(KH3O) (Al, Mg, Fe)2 (Si, Al)4O10[(OH)2, (H2O)]	-	+	-	-	+	−	+	−	−	−
Kaolinite	Al2Si2O5(OH)4	+	+	-	-	-	+	−	−	−	−
K-Feldspar	KAlSi3O8	+		-	-	-	+	−	−	−	−
Pyrite	FeS2	+	+	+	+	-	+	+	+	+	−
Cristobalite	SiO2	+	-	-	-	-	+	−	−	−	+
Chalcopyrite	CuFeS2	-	-	+	+	+	−	+	+	+	+
Biotite	K(Mg,Fe)3 (Al Si3O10) (F, OH)2	-	-	+	+	-	−	−	+	+	−
Hematite	Fe2O3	+	-	-	-	-	+	+	+	+	+
Ilmenete	FeTiO3	+	-	-	+	-	+	+	−	−	−
Rutile	TiO2	+	+	-	-	-	+	+	−	−	−

Figure 4. (a) XRD of the atmospheric dust sample collected from copper mining area. (b) XRD of the atmospheric dust sample collected from iron mining area

Figure 4. (Continued)

Mineral characteristics of dustfall in iron mining area

The XRD image of dust samples of Iron mining area is depicted in Figure 4b. Quartz, hematite, magnetite, albite, and pyrite are the main minerals contained in the dust samples (Table 4). CaCO³ was reported to be abundant in atmospheric dust in India (Kulshrestha et al. 2003). The high values of suspended particulate matter were reported due to crustal sources (Kulshrestha, Kumar, and Saxena 1995). Gypsum in atmospheric dust may be due to the adsorption of SO₂ on soil-derived CaCO₃ particles that form CaSO₄.2H₂O (Kulshrestha 2013). Yadav and Rajamani (2006) published about quartz supremacy. Quartz presence in all samples as a major component shows that the dust is predominantly from soil/earth crust sources. In all samples, quartz is a common mineral. The health effects of quartz in the dust are well accepted; a Chinese study found nano-quartz particles in a bituminous carbon seam and in the lungs of rural residents who were burning this coal in their homes (Dai et al. 2008).

Conclusion

The present study was carried out in the copper and iron mining areas of East and West Singhbhum. The highest dustfall rate occurred at Adityapur industrial area, East Singhbhum, and the highest dustfall occured at the Hathigate, West Singhbhum, which is under the influence of extensive traffic load. The atmospheric dustfall levels were found to be higher during the summer season due to increased dispersion owing to high wind speed during the summer. The lower rates observed during the winter season may have been due to the monsoonal rainfall washout and higher relative humidity. The major minerals found in the dustfall samples of copper mining area are quartz, muscovite, chlorite, calcite, chalcopyrite, albite, gypsum, and dolomite. In the dust samples of iron mining area, the major minerals identified are quartz, cristobalite, hematite, magnetite, biotite, albite, ilmenete, pyrite, rutile, and dolomite. The present study considered the extent of dustfall rates and their mineral characteristics. Thus, an immediate need is there to monitor dust pollution in the study area and  implement suitable dust control system viz. wet dust suppression and airborne dusts capture for dust abatement.

Acknowledgment

The authors thank the China Section of the Air & Waste Management Association for the generous scholarship they received to cover the cost of page charges, and make the publication of this article possible. The authors also thank the editors and reviewers for their insightful comments and suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors are grateful to the Science and Engineering Research Board (SERB), GoI, for providing the necessary funding for the study under the National Postdoctoral Fellowship (N-PDF) Scheme (Grant No. PDF/2017/000953/EAS). Also authors are thankful to the Director, CSIR–Central Institute of Mining and Fuel Research, Dhanbad, for providing the necessary laboratory.

Notes on contributors

Mukesh Kumar Mahato

Mukesh Kumar Mahato is a post-doctoral researcher in the Natural Resources and Environment Management Research Group, CSIR-Central Institute of Mining and Fuel Research, Dhanbad, India, having a research experience of more than 5 years after the completion of Ph.D. in the field of environmental Science. His research interest is mainly in distribution of toxic metals in wet and dry atmospheric depositions, source evaluation and human health risk assessment. He has published more than 30 research articles in reputed peer reviewed national and international journal.

Abhay Kumar Singh

Abhay Kumar Singh is a Senior Principal Scientist in the Natural Resources and Environment Management Research Group at CSIR-Central Institute of Mining and Fuel Research, Dhanbad, India. His major research interest is Environmental geochemistry, Major ion chemistry of coal mine water and its management, Atmospheric chemistry of dry and wet depositions, Source and mechanism controlling the surface and sub-surface water chemistry and impacts of mining and industrial activities on the water, sediment and dust quality. He has published more than 80 research articles in reputed peer reviewed national and international journal.