Retention times of Pb, Cd, Cu and Zn in children's blood

Estimation of the pooled mean blood lead levels of Indian children: Evidence from systematic review and meta-analysis

A recent systematic review reported very high pooled estimates of blood lead levels (BLLs) for Indian children. Current study aimed at systematically pooling the BLLs of Indian children (aged ≤ 14 years). Further, explore the time trend of BLLs with respect to implementing the ban on the use of Pb-petrol (i.e.2000) and a decade later (2010). Observational studies documenting the BLL in Indian children (aged ≤ 14 years) from PubMed-Medline, Scopus, and Embase digital databases from inception to August 2024 were systematically reviewed. Detailed protocol is available at PROSPERO (ID: CRD42022382835). Pooled mean BLL was estimated using the random-effects model and conventional-I 2 statistics to assess the heterogeneity, while the Newcastle Ottawa Scale for bias assessment. Sub-group, sensitivity, and meta-regression analyses were performed where data permitted. Observations from 65 reports (51 original studies) revealed pooled BLL of 10.4 (95 % CI: 9.55-11.2) µg/dL with a trend of gradual reduction during the last 3 decades. Subgroup analysis revealed the high risk (with known Pb exposure) children had BLL of 14.3 (12.3-16.2) µg/dL, while that of the low risk (no known Pb exposure) is 8.71 (7.71-9.71) µg/dL. Only the low risk group exhibited a time trend of a gradual reduction in BLL. Notably, the review observed high heterogeneity. A progressive decline in Pb burden with respect to the national ban on leaded petrol was observed. However, present observations emphasize remedial actions toward non-occupational Pb exposure particularly among high risk Pb group, such as periodic BLL surveys.

Elevated serum lead levels in neonates born to mothers suffering from opiate use disorder

BACKGROUND

This study was performed to investigate lead levels in neonates born to the mothers suffering from opiate use disorder (OUD) and the association of lead levels with the Apgar score.

METHODS

The present cross-sectional study included 56 neonates who were referred to the neonatal ward of Amir-Al Momenin Hospital, Zabol. The neonates were divided into two groups: the neonates whose mothers suffered OUD and the control group. Data were collected using a researcher-prepared questionnaire, and blood lead level was determined using the atomic absorption method. Data were statistically analyzed.

RESULTS

In all, 56 neonates (28 from OUD mothers and 28 from the control mothers) were included in this study. Among the women with OUD, 16 (57%) used inhaled opium, while 12 (43%) consumed opium orally. There was a significant difference regarding Apgar score (9.76 ± 2.11 versus. 7.11 ± 4.21; p = 0.02) and the neonate's blood lead level (2.33 ± 1.3 µg/dl versus 7.33 ± 5.9 µg/dl) between the control and OUD groups (p < 0.001). The odds ratio of abnormally elevated blood lead level rose with increasing duration of maternal opiate disorder for opiate usage durations of 3 to 5 years (adjusted odds ratio [OR] 42.82, 95% confidence interval [CI] 3.27-561, p = 0.004) and > 5 years (adjusted OR 45.5, 95% CI 2.97-698, p = 0.006).

CONCLUSION

The results of this study suggested a significant relationship between maternal opium consumption during pregnancy and neonatal serum lead levels, as well as decreased neonatal Apgar score.

Ratiometric G-Quadruplex Assay for Robust Lead Detection in Food Samples

Lead (Pb²⁺) pollution is a serious food safety issue, rapid detection of Pb²⁺ residual in food is vital to guarantee food quality and safety. Here we proposed ratiometric aptamer probes, allowing robust Pb²⁺ supervision in food samples. Pb²⁺ specific aptamer can bolster a transition of G-quadruplex structural response to Pb²⁺; this process can be monitored by N-methyl mesoporphyrin IX (NMM), which is highly specific to G-quadruplex. Particularly, the utilization of G-quadruplex specific dye and terminal-labeled fluorophore allowed to endue ratiometric signal outputs towards Pb²⁺, dramatically increase the robustness for lead detection. The ratiometric G-quadruplex assay allowed a facile and one-pot Pb²⁺ detection at room temperature using a single-stranded DNA aptamer. We demonstrated its feasibility for detecting lead pollution in fresh eggs and tap water samples. The ratiometric G-quadruplex design is expected to be used for on-site Pb²⁺ testing associated with food safety.

Intermittent lead-induced stress on antioxidant enzyme activity and subcellular distribution of Pb in Pogonatherum crinitum seedlings

Pogonatherum crinitum is a promising lead (Pb) hyperaccumulator due to its high Pb tolerance and accumulation ability. However, the mechanisms that support Pb accumulation and tolerance in P. crinitum are not yet clearly understood. An indoor hydroponic experiment was conducted by cultivating P. crinitum seedlings exposed to intermittent Pb stress for 60 days, divided into four stages (T1, T2, T3 and T4), with a 15-day duration per stage. The following concentrations of Pb were used: 0, 500, 0, 500 mg·l^-1 and 0, 1000, 0, 1000 mg·l^-1 ). Antioxidant enzyme activity, Pb concentration and subcellular distribution of Pb were measured at each of the above stages. The results showed that superoxide dismutase (SOD) activity in shoots, and SOD, peroxidase (POD) and malondialdehyde (MDA) activity in shoots and roots significantly increased from T1 (no Pb stress) to T2 (Pb stress) in both 500 mg·l^-1 and 1000 mg·l^-1 treatments; however, no significant difference was noted between stages T3 (no Pb stress) and T4 (Pb stress). There was no obvious effect of Pb stress on catalase (CAT) activity in shoots and roots among different stages. The Pb concentration in shoots was up to 5090.90 mg·kg^-1 and 7573.57 mg·kg^-1 , and the bioconcentration factor (BFC) was 10.18 and 7.57 for the 500 mg·l^-1 and 1000 mg·l^-1 treatments, respectively, which confirmed the Pb hyperaccumulator characteristics of P. crinitum. For plants under Pb stress, most of the Pb was fixed in the cell walls, with a smaller amount in leaves and root vacuoles. Both SOD and POD scavenging of reactive oxygen radicals and fixing and compartmentalisation of Pb in the cell wall might play important roles in detoxification of P. crinitum seedlings in response to Pb stress. There was no phased response of P. crinitum to intermittent Pb stress and the physiological response to Pb stress may be contiguous.

Prevalence of cymothoid isopods (Crustacea, Isopoda) and proximate analysis of parasites and their host fishes, Southeastern India

Cymothoid isopods (Crustacea, Isopoda) are considered as potential threat to the health of different fish species. In order to evaluate the prevalence and proximate analysis of Cymothoid isopods and its host, an investigation was carried out fish species belonging to families Hemiramphidae and Belonidae in the Palk Bay region, Southeastern India. A total of 1265 individuals of teleost fish belonging to family Hemiramphidae species, Hemiramphus far (462), H. archipelagicus (78), and H. lutkie (277) and another family Belonidae species, Tylosurus crocodilus (448), were examined for cymothoid ectoparasitic infestation. Prevalence in H. far was the highest (39%) for the cymothoid Mothocys plagulophora, while T. crocodilus was most infested (13%) with Mothocys renardi, H. far and H. lutkie were not infested by M. renardi while T. crocodilus was not infested by M. plagulophora. Proximate analysis showed reduced level of protein in parasite infested fish compared with non-infested individuals. However, carbohydrate and lipid concentrations were lower in infested fish than non-infested individuals. Proximate analysis values in the two parasites of Mothocys species were similar, and these values were comparable to those unaffected fish species indicating that parasites were well nourished. The proximate analysis of isopod parasite M. plagulophora showed 21.6 ± 7.7, 1.26 ± 0.05, 5.49 ± 1.06% of protein, carbohydrate and lipid respectively, and in M. renardi, 21.09 ± 6.6, 1.32 ± 0.12, 5.83 ± 0.72% of protein, carbohydrate and lipid respectively. Cadmium levels were similar between affected and non-affected fish individuals and among species. The Pb levels were comparable among all T. crocodilus individuals, but the levels of Cd not showed much variation between affected and unaffected individuals in all four fish species.

Analysis of trace elements (Cu, Cd, and Zn) in the muscle, gill, and liver tissues of some fish species using anodic stripping voltammetry

Heavy metal (Cu, Cd, Zn) concentration of the muscle, gill, and liver of Otolithes rubber, Pampus argenteus, Parastromateus niger, Scomberomorus commerson, and Onchorynchus mykiss are determined by anodic stripping voltammetry method. The results show that the concentration of Cu, Cd, and Zn varied between 0.44 and not detected, 0.585 and 0.001, and 0.450 and 0.005 μg/g, respectively. It is interesting that in O. mykiss, the mean value of copper concentration was more than other marine organisms of this study, while in P. niger, the mean value of copper was minimum. The results of this study indicate that in the different tissues of fish species (O. rubber, P. argenteus, P. niger, S. commerson, and O. mykiss), the concentrations of Cu, Cd, and Zn were significantly lower than the permissible FAO/WHO levels.

Relationship between Painful Crisis and Serum Zinc Level in Children with Sickle Cell Anaemia

Sickle cell anaemia (SCA) is associated with zinc deficiency; zinc supplementation may ameliorate some of its clinical manifestations including the relief of painful crisis. Subjects and Methods. Serum zinc levels were determined in 71 children with SCA and painful crisis and in equal numbers in steady state. Seventy-one children with AA genotype acted as controls. Qualitative assessment of zinc content of 24-hour dietary recall and the last meal consumed before blood was drawn was taken. Serum zinc was determined using atomic absorption spectrophotometer. Haemoglobin concentration and packed cell volume (PCV) were determined using standard methods. Results. The mean serum zinc concentration in the study was less than international reference range. The controls had significantly higher serum zinc concentrations than the SCA group (42.7 ± 13.6 versus 32.3 ± 14.0 μg/dL, P < .000); this difference was due to the significantly lower values of serum zinc in SCA with painful crisis compared with the remaining two groups F = 30.9, P<.000. There was a positive correlation between serum zinc and haemoglobin concentration only in the control group (r = 0.4; P = .001). Conclusion. The serum zinc levels in this study were low. Painful crisis in SCA may exert greater demand for zinc utilization in children with SCA thereby resulting in lower serum levels.

Analysis of heavy metals in marine fish from Mumbai Docks

Seafood containing heavy metals as a result of environmental contamination causes toxicity in human beings. To evaluate such kind of contamination, our study targeted the analysis of metals such as lead, copper, cadmium, mercury, and arsenic in muscle tissue of the fish. The fish commonly consumed such as Brama brama (Pomfret), Rachycentron canadus (Surmai/King Fish), Rastrelliger kanagurta (Mackerel), Eleutheronema tetradactylum (Ravas/Indian salmon), and Metapenaeus monoceros (Brown Prawn) were collected from four different docks in the city. The heavy metals in tissue samples of fish were estimated using voltammeter and cold vapor atomic absorption spectrophotometer. Heavy metal concentration in the tissues varied significantly depending upon the locations from where the fish were collected. Although the concentration of arsenic, copper, cadmium, and lead were in normal range, the concentration of mercury was found to exceed the daily permissible levels (1 microg/g) as a food source for human consumption. We have analyzed heavy metals from different locations in Mumbai-Versova dock, Sassoon dock, Navi Mumbai dock, and Mazgaon dock.

Daily intakes of copper, zinc and arsenic in drinking water by population of Shanghai, China

Daily intakes of metals in drinking water are of extreme importance in risk assessment to human health. Some papers focused on this topic, but most of them did not consider the effect of age, gender and work location on daily intakes of metals in drinking water. The objective of present paper is to estimate the levels of Cu, Zn and As ingestion in drinking water in Shanghai, China and the effect of age, gender and work location on daily intakes of these metals. It was also the first time that such a detailed investigation on daily intakes of metals in drinking water was carried out in China in recent years. Drink/Sample (D/S) method was used to estimate the daily intakes of Cu, Zn and As in drinking water. The mean concentrations of Cu, Zn and As in drinking water were 10.8 microg/l, 0.29 mg/l and 0.91 microg/l, which were lower than U.S. EPA's Drinking Water Equivalent Level (DWEL) and WHO guideline values. The average daily intakes of Cu, Zn and As in drinking water was 21.12 microg/d, 0.65 mg/d, and 1.83 microg/d, which were on average 0.01%, 1.1% and 1.5% of the provisional maximum tolerable daily intake (PMTDI) set by the Joint FAO/WHO Expert Committee. There was a significant difference in daily intake of Zn for different work locations (P=0.04). But no other significant differences in daily intakes of metals in drinking water were found according to age, gender and work location.

Spatial variations in selected metal contents and particle size distribution in an urban and rural atmosphere of Islamabad, Pakistan

Spatial variations in total suspended particulate matter (TSP) were investigated for distribution of metals and particle size fractions in the urban and rural atmosphere of Islamabad, Pakistan. The metals Na, K, Fe, Mn, Pb, Cd, Cr, Zn, Ni and Co, and the particle fractions <2.5, 2.5-10, 10-100 and >100 microm were included in the study. TSP samples were trapped on glass fibre filters using high volume samplers and quantification of metals was done using Atomic Absorption Spectrometry employing HNO(3) based wet digestion. At the urban site, Na was dominant at 2.384 microg/m(3) followed by K, Fe and Zn with 0.778, 0.667 and 0.567 microg/m(3) as mean concentrations, respectively. The metal levels for the rural site ranged from 0.002 microg/m(3) for Cd to 1.077 microg/m(3) for Na. However, compared with the urban site, mean Pb concentration showed an almost two-fold enhancement, i.e., 0.163 Vs. 0.327 microg/m(3). Metals and particle size source identification was done using Principal Component Analysis and Cluster Analysis. Five sources were traced out for the urban site: industrial, soil, automobile emissions, metallurgical industries and excavation activities. For the rural site, four sources were recorded: agricultural, automotive emissions, excavation activities and metallurgical units. Collectively, for both the sites, PM(10-100) emerged as a major contributor to TSP, followed by PM(2.5-10), PM(<2.5) and PM(>100) in that order. The metals showed in general positive relationship with fine particulate fractions (PM(2.5-10), PM(<2.5)), and negative correlation with coarse fractions (PM(10-100), PM(>100)). Comparison with the corresponding data from various Asian sites revealed that the levels of Na, K, Fe, Mn, Co and Ni for the present study were lower than those reported for grossly polluted cities of the world.

Toxic metals status in human blood and breast milk samples in an integrated steel plant environment in Central India

Owing to its unique nutritional and immunological characteristics, human milk is the most important food source for infants. Breast milk can, however, also be a pathway of maternal excretion of toxic elements. Selected toxic elements (As, Pb, Mn,a Hg and Cd) were determined in human breast milk and blood samples obtained from 120 subjects related to an integrated steel plant environment located in central India. Samples of breast milk and blood from subjects living outside the steel plant environment were also analyzed for comparative study. Higher levels of these toxic elements were found in blood samples as compared to breast milk samples. Plant workers showed the higher presence of these metals in their breast milk and blood samples compared to the residents of the area and the subjects living outside the industrial environment, respectively. Mn, Pb and Hg have shown a higher tendency to associate with blood and breast milk than As and Cd. The order of occurrence of these metals in blood and milk samples thus found is Mn > Pb > Hg > As > Cd.

Screening of Urban Aerosol Particulate Composites for Selected Metal Distribution and Their Dependence on Meteorological Parameters

Local atmospheric aerosol particulate samples, collected as composites on daily 6-12 hour basis, at Quaid-i-Azam University campus, Islamabad, Pakistan, using high volume sampling technique, were analysed for Pb, Na, K, Fe, Mn, Cd, Cr, Ni, Zn and Co by FAAS method. The monitoring period ran from October, 2001 through March, 2002, with a total of 105 samples collected on cellulose filters, treated in part with the HNO3-based wet digestion method for metal quantification, and for particle size distribution separately. The metal content of the aerosols was examined in relation to dependence on meteorological parameters, such as temperature, relative humidity, wind speed, sun shine and pan evaporation. Statistical correlation analysis was conducted for multiple metal pairs in aerosols, and the data were examined in relation to meteorological parameters and relevant aerosol particle size fractions. The study revealed no viable strong correlation between the meteorological parameters and metal levels; in general, however, a significant positive correlation was found for temperature. A strong positive correlation was observed for PM<25 and PM2.5-10. For coarse particles (PM10-100 and PM>100), however, a negative correlation was observed. The levels of Na, K, Fe and Zn were found in the range of 1-5 microg/m3 while those for the rest of the metals in the sub microg/m3 range. Principal component analysis and cluster analysis were performed on dataset for source identification and appointment. Largest contribution (33%) was shown by the industrial emissions followed by traffic/road dust (16.7%).

Atmospheric and children's blood lead as indicators of vehicular traffic and other emission sources in Mumbai, India

Average concentration of Pb in atmospheric air particulates in different suburbs of Mumbai was studied for almost a decade and its spatial and temporal profiles are discussed in relation to emission sources. In general the concentration of Pb in all the residential suburban atmosphere is well below the Central Pollution Control Board (CPCB, 1994) prescribed limit of 1.5 microg m(-3) barring a few exceptions for some residential/industrial sites, such as those of Thane and Kurla scrap yards. The correlation between blood lead of children and air lead reveals that the blood Pb level in children could increase by 3.6 microg dl(-1) for an incremental rise of 1.0 microg Pb m(-3) of air. The temporal profile of air Pb values indicates a decreasing trend in residential suburbs (Khar: 1984, 0.39 microg m(-3); 1996, 0.17 microg m(-3)) as well as in suburban residential areas with low traffic (Goregaon: 1984, 0.53 microg m(-3); 1996, 0.30 microg m(-3)).

Daily intake of trace metals through coffee consumption in India

The trace element contents of five varieties of instant coffee powder available in the Indian market have been analysed. Ca, Cr, Fe, K, Mg, Mn, Ni, Sr, Zn and Pb, Cd, Cu have been determined using atomic absorption spectrophotometry and differential pulse anodic stripping voltammetry, respectively. The metal levels in the coffee powders observed in this study are comparable with those reported for green coffe beans (Arabica and Robusta variety) reported worldwide with the exception of Sr and Zn, which were on the lower side of the reported values. Concentrations of these metals have been converted into intake figures based on coffee consumption. The daily intakes of the above metals through ingestion of coffee are 1.4 mg, 1.58 microg, 124 microg, 41.5 mg, 4.9 mg, 17.9 microg, 2.9 microg, 3.8 microg, 12.5 microg, 0.2 microg, 0.03 microg and 15.5 microg, respectively. The values, which were compared with the total dietary, intake of metals through ingestion by the Mumbai population, indicate that the contribution from coffee is less than or around 1% for most of the elements except for Cr and Ni which are around 3%.

Daily intake of manganese by the adult population of Mumbai

The daily intake of manganese (Mn) estimated through air, water and duplicate dietary analysis is found to range from 0.67 to 4.99 mg with a mean value of 2.21 mg. Ingestion through food contributed to the predominant fraction of the intake. The turnover rate of Mn through blood is approximately 2 h, based on the mean concentration of Mn in blood of 1.54 microg l(-1). The average concentrations of Mn in water and air were approximately 1.42 microg l(-1) and 37 ng m(-3), respectively. The daily intake of Mn by the adult population of Mumbai is closer to the lower bound of the recommended limit of 2-5 mg. Electro Thermal Atomic Absorption Spectrophotometry (ET-AAS), has been used for the determination of Mn in a variety of environmental and human biological fluids. The detection limit of Mn for a volume injection of 20 microl is 2 pg absolute. The precision of the method is established by analyzing a synthetic mixture containing various elements in different quantities (0.5-10 ppm) and is found to be within +/- 8%. The reliability of estimation is further assessed through the analysis of Standard Reference Materials (SRMs) of soil, hay, milk powder and fish tissue obtained from IAEA.

Daily intake of heavy metals by infants through milk and milk products

Concentrations of the essential elements Zn and Cu and potentially toxic elements Pb and Cd in different milk samples and baby food materials were measured, primarily to assess whether the intakes comply with recommended desired levels for essential and permissible levels for toxic elements. The geometric mean concentrations of Pb, Cd, Cu and Zn in different types of milk were found to vary from 1.70 to 3.35, 0.07 to 0.10, 43.2 to 195 and 1772 to 4230 micrograms/l, while the same in different baby foods had values from 39.5 to 77.7, 0.45 to 17.7, 1106.3 to 3157.3 and 9367 to 34,592 micrograms/kg, respectively. The concentration of Cd was found to be very low (0.1 microgram/l) and fairly constant in all types of milk. The lead content in cow milk was observed to be lowest even in comparison with breast milk. Concentrations of all these metals are approximately one order of magnitude higher in baby food products than those observed in different types of milk owing to higher fat content. The infant baby food Amul Spray contains low concentrations of toxic (Pb and Cd) and high concentrations of essential (Cu and Zn) elements. The daily intakes of Pb, Cd, Cu and Zn by infants through milk and baby foods marketed in Mumbai city have also been estimated. The daily intakes of Pb (1.1 micrograms/kg) and Cd (0.01 microgram/kg) for infants through baby foods are well below the recommended tolerable levels of 3.57 micrograms/kg and 0.8-1.0 microgram/kg, respectively. Similarly the daily intake levels of essential elements are also significantly lower than the recommended desirable levels of 3-5 mg and 0.5-1.0 mg for Zn and Cu, respectively. Milk from an Indian mother also does not provide adequate levels of essential elements to the infants and children.

The distribution of lead within ancient and modern human teeth: implications for long-term and historical exposure monitoring

The preservation of lead within human tissue makes it possible to monitor long-term exposure to the element and to model changing sources of lead pollution throughout the lifetime of an individual. Dental tissues have recently been shown to be particularly useful for this purpose. Enamel, for instance, forms at known stages of life and is chemically stable in vivo whereas dentine is remodelled in a predictable fashion. The relative stability of enamel is reflected in its excellent post-mortem preservation. This raises the possibility of using historical or archaeological material to reconstruct long-term trends and establish baseline data relating to exposure among pre-industrial or even prehistoric populations. The use of archaeological material is currently problematic, however, because of the site-specific nature of diagenesis and incomplete understanding of its chemistry, particularly in respect of lead uptake into dental tissue from the burial environment. A detailed study of lead distribution within both ancient and modern human teeth is presented. Conclusions are drawn on the pattern of lead distribution resulting from tissue formation and the manner of its alteration in the burial environment. In particular, attention is drawn to a consistent enrichment of lead within the outer 30 microns of the enamel of both ancient and modern teeth which appears to be unrelated to diagenesis. The implications for current approaches to long-term monitoring and for the reconstruction of historical and archaeological exposure patterns are discussed.