Residues and contaminants in medicinal herbs—A review

With the increasing popularity and use of medicinal herbs, their global demand has gained momentum. Developing countries, including China, India and South East Asian (SEA) countries, are the centres of origin and major global suppliers for most of these traditionally used medicinal herbs. One of the factors affecting the quality of these herbs is the contamination of heavy metals, mycotoxins, pesticide residues, polycyclic aromatic hydrocarbons (PAHs) and fumigants. These contaminants can accumulate during the cultivation, storage and processing of herbs and may have adverse effects on consumer health. There have been various reports regarding the presence of these contaminants in medicinal herbs. This review discusses the important contaminants of medicinal herbs, the frequency and magnitude of their occurrences, the potential causes of contamination and their regulatory limits in medicinal herbs. The major challenge in the international trade of medicinal herbs is the lack of common guidelines, regulatory measures and monitoring body to strictly enforce their regulation.     

Presence and possible origin of positive Eu anomaly in shoot samples of Juncus effusus L

BackgroundThe rare earth elements (REE) are non-essential elements for plants. They stimulate plant growth at low doses, but at high levels are phytotoxic. There are differences in concentrations of REE in various organs of the same plant species, but the normalized REE patterns can be very similar in samples of the same species collected in different locations. Here we compare normalized REE curves in above-ground samples of Juncus effusus L. (common rush, soft rush) collected from sites with different land-use types.MethodsThe concentrations of rare earth elements were measured in 55 shoot samples of J. effusus L. The samples were collected from 15 sampling sites located in the Holy Cross Mts., south-central Poland and analyzed with the use of inductively coupled plasma mass spectrometry (ICP-MS). The results were normalized to the North American Shale Composite and anomalies of different elements were calculated.ResultsTotal REE concentrations varied from 0.028 mg/kg to 2.7 mg/kg. The samples were enriched in the light REE (from La to Eu) with the highest concentrations of La and Ce. The North American Shale Composite (NASC)-normalized REE curves were roughly similar in all samples except for two samples collected in the acid mine drainageaffected areas.ConclusionAll samples showed positive europium anomalies in NASC-normalized REE concentration patterns. The most probable explanation of this is that the uptake and translocation of Eu in J. effusus (and possibly in other wetland plants) is caused by a short-term decrease of the redox potential in a rhizosphere favoring reduction of Eu³⁺ to Eu²⁺ and thus enhancing Eu mobility in the soil-plant environment.     

Analysis and assessment of heavy metals pollution in soils around a Pb and Zn smelter in Baoji City,Northwest China

Soil heavy metal pollution from mining activities is potentially harmful to human health through the food chain. In this study, a total of 43 soil samples were collected from a depth of 0–20 cm from fields close to a Pb and Zn smelter. The samples were used to: 1) analyze the pollution level of heavy metals (Pb, Zn, Cr, and Cu) and spatial distribution pattern; 2) evaluate the degree of accumulation and enrichment, potential ecological risk, and human health risk; and 3) perform source apportionment in Fengxiang County, Shaanxi Province of China. The results showed that the concentration ranged from 43.67 to 189.55, 131.43 to 239.53, 74.77 to 112.25, and 24.69 to 37.71 mg·kg^?1 for Pb, Zn, Cr, and Cu, respectively, and the mean concentration for Pb, Zn, Cr, and Cu was 129.46, 192.85, 91.98 and 31.67 mg·kg^?1, respectively. The concentrations were greater than the Shaanxi Province background values, while they were lower than the second-level limits of Environmental Quality Standard for Soils of China (EQSS). The spatial distribution of heavy metal contents showed a banded in soil except Cu. The spatial distribution pattern and pollution assessment indexes (I_geo, EF) indicated that the investigated metals had been accumulated in the study areas, and implied significant influences from anthropogenic activities, local meteorological situation, and soil properties. The ecological risk assessment showed that the risks were relatively low (RI<150). Compared with the exposure risk for adults, that for children was significantly greater. The ingestion of heavy metals in the soils by humans was the main exposure pathway compared with the dermal exposure. There may be a risk of noncarcinogenic adverse health effects (HQ < 1, 0.377 ≤ HI≤1.553) on children, but the adults were unlikely to experience obvious adverse health effects (HQ < 1, HI < 1). The carcinogenic risk of Cr for adults and children was at an unacceptable level. The carcinogenic and noncarcinogenic risks were in the order of children > adults. The correlation analysis showed that Pb, Cr, and Cu have identical anthropogenic and natural sources, while Zn has another identical source. This study could provide a basis for the sustainable management of this region by reducing metal inputs and to protect soils from long-term heavy metal accumulation.     

Can transposable element copy number distribution parameters be estimated from natural populations of Drosophila melanogaster?

The copy frequency distribution of a transposable element family in a Drosophila melanogaster natural population is generally characterised by the values of the Charlesworths' model parameters α and β (Charlesworth & Charlesworth, 1983). The estimation of these parameters is made using the observed distribution of the occupied sites in a population sample. Several results have been interpreted as due either to the influence of stochastic factors or to deterministic factors (transposition, excision, selection…). The accuracy of this method was tested by estimations performed on samples from simulated populations. The results show that with the sample size usually used for natural population studies, the confidence intervals are too large to reasonably deduce either the element copy number distribution or the values of transposition and excision rate and selective coefficients.     

Metal and essential element levels in hair and association with autism severity

BackgroundAutism Spectrum Disorder (ASD) is a complex disorder with heterogeneous etiology and wide clinical severity which supports the needs of recognizing biological and clinical features in patient subsets. The present study aimed to understand possible associations between the hair levels of metals and essential elements and some specific features of ASD measured by the Autism Diagnostic Observation Schedule (ADOS) that represents the gold-standard instrument to objectively confirm ASD diagnosis.MethodsA cross-sectional study was performed in the province of Catania (Sicily, South Italy). Forty-eight subjects with ASD (70.8% male), aged from 2 to 17 years were studied. Metals (Li, Be, Al, Ni, As, Mo, Cd, Hg, U, Pb) and essential trace elements (Cr, Co, Mn, Zn, Cu, Se) were quantified in hair by inductively coupled plasma mass spectrometry analysis. Participants were characterized by measuring the severity of autism symptoms and cognitive levels.ResultsA significant and positive correlation was found between hair metal burden (lead, aluminum, arsenic and cadmium levels) and severity of ASD symptoms (social communication deficits and repetitive, restrictive behaviors). Hair zinc level were inversely related with age while there was a negative, significant association between hair zinc level and severity of autistic symptoms (defective functional play and creativity and increase of stereotyped behavior). Lead, molybdenum and manganese hair levels were inversely correlated with cognitive level (full intelligence quotient) in ASD individuals.ConclusionsThe present study suggests the importance to combine metallomics analysis with pertinent disease features in ASD to identify potential environmental risk factors on an individual level possibly in the early developmental period.     

Health risk assessment via consumption of Pb and Cd contaminated vegetables collected from fresh markets in the lower north of Thailand

This study aimed to investigate the Pb and Cd contamination and health risk assessment for population via consumption of vegetables sold in fresh markets around the lower north of Thailand. The concentrations of Pb and Cd in various vegetables such as root/tuber, stem, inflorescence, fruit, and leaf vegetables were analyzed using an atomic absorption spec-trophotometer. Human health risks of these metals in vegetables were assessed based on target hazard quotient (THQ). The results indicated that more than 80% of the Pb and Cd in almost all vegetable samples exceeded the maximum allowable concentration by National Food Institute criteria with an average range of 0.96–3.39 and 0.48–1.40 mg/kg, respectively. The estimated daily intakes (EDI) of Pb and Cd via dietary consumption of vegetables were between 0.001–0.010 and 0.002–0.008 mg/kg/d, respectively. All EDIs of Pb contaminated vegetables were higher than the reference dose recommended by the USEPA except for leaf edible vegetables, while all EDIs of Cd contaminated vegetables were higher than the reference dose recommended by the USEPA. THQ indicated that the consumption of Pb contaminated root/tuber, stem, inflorescence, and fruit edible vegetables and Cd contaminated leaf vegetable for the local population in the lower north of Thailand could be a severe health risk problem.     

Twins are more different than commonly believed,but made less different by compensating behaviors

Twin studies are popular, because twins are believed to be the same/similar in genes and environmental exposures. It is well documented, however, that the firstborns are healthier at birth. We use the entire U.S. record of twin births during 1995–2000 to show that the survival duration parameters differ between twins depending on the birth order. We also find that wiser (i.e., older or educated) or married (i.e., resource-richer) mothers take more care of the weaker, which is a “compensating” behavior reducing the twin difference, as opposed to “reinforcing (the twin difference)” behavior. The systematic survival pattern difference and the mother's intervention against nature send cautions to twin studies that regard twins homogeneous to interpret their findings accordingly. Since the survival duration in our data is 97% right-censored in one year, we devise a quantile-based ‘fixed-effect’ semiparametric estimator that can handle heavy censoring, which is our methodological contribution.     

Heavy metal pollution in surface water and sediment: A preliminary assessment of an urban river in a developing country

The concentration and chemical fractionation of globally alarming six heavy metals (Cr, Ni, Cu, As, Cd and Pb) were measured in surface water and sediment of an urban river in Bangladesh. The decreasing trend of metals were observed in water as Cr > Cu > As > Ni > Pb > Cd and in sediment as Cr > Ni > Cu > Pb > As > Cd. The level of studied metals exceeded the safe limits of drinking water, indicated that water from this river is not safe for drinking and/or cooking purposes. However, the investigated metals showed low mobility except for Cd and Pb which could pose a severe threat to the aquatic environment. Contamination factor (CF) and geoaccumulation index (I_geo) demonstrated that most of the sediment samples were moderately to heavily contaminated by Cr, As, Cd and Pb. The pollution load index (PLI) values were above one (>1) indicates progressive deterioration of the sediment quality. The extent of pollution by heavy metals in the river Korotoa implies that the condition is much frightening to the biota and inhabitants in the vicinity of the river as well.