Potential of Opuntia ficus-indica for air pollution biomonitoring: a lead isotopic study.

Opuntia ficus-indica (Ofi) is a long-domesticated cactus that is widespread throughout arid and semiarid regions. Ofi is grown for both its fruits and edible cladodes, which are flattened photosynthetic stems. Young cladodes develop from mother cladodes, thus forming series of cladodes of different ages. Therefore, successive cladodes may hold some potential for biomonitoring over several years the local atmospheric pollution. In this study, cladodes, roots, dust deposited onto the cladodes, and soil samples were collected in the vicinity of three heavily polluted sites, i.e., a fertilizer industry, the road side of a highway, and mine tailings. The lead content was analyzed using atomic absorption spectroscopy (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS). Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX) was used to characterize the cladode surfaces and the nature of dust deposit, and the lead isotopes were analyzed to identify the origin of Pb. The results show that (i) Ofi readily bioaccumulates Pb, (ii) the lead isotopic composition of cladodes evidences a foliar pathway of lead into Ofi and identifies the relative contributions of local Pb sources, and (iii) an evolution of air quality is recorded with successive cladodes, which makes Ofi a potential biomonitor to be used in environmental and health studies.

Health hazard prospecting by modeling wind transfer of metal-bearing dust from mining waste dumps: application to Jebel Ressas Pb-Zn-Cd abandoned mining site (Tunisia).

This work presents a modeling approach to simulate spatial distribution of metal contamination in aerosols with evaluation of health hazard. This approach offers the advantage to be non-intrusive, less expensive than sampling and laboratory analyses. It was applied to assess the impact of metal-bearing dust from mining wastes on air quality for a nearby community and agricultural lands in Jebel Ressas (Tunisia) locality. Dust emission rates were calculated using existing parameterization adapted to the contamination source composed of mining wastes. Metal concentrations were predicted using a Gaussian model (fugitive dust model) with, as input: emission rates, dump physical parameters and meteorological data measured in situ for 30 days in summertime. Metal concentration maps were built from calculated PM10 particle concentrations. They evidence the areas where Pb and Cd concentrations exceeded WHO guidelines (0.5 and 0.005 µg/m(3), respectively). Maximum concentrations of Pb and Cd in PM10 are, respectively, of 5.74 and 0.0768 µg/m(3) for measured wind speed values up to 22 m/s. Preferential areas of contamination were determined in agricultural lands to the NW from the source dump where Pb and Cd exceeded guidelines up to a distance of 1,200 m. The secondary spreading directions were SW and E, toward the village. Health hazard prospecting shown that a major part of the village was exposed to contaminated dust and that daily hazard quotient (HQ) values reached locally 118 and 158, respectively, for Pb and Cd during the study period. However, HQ variations in the village are high, both temporally and geographically.

Multielementary (Cd, Cu, Pb, Zn, Ni) Stable Isotopic Exchange Kinetic (SIEK) method to characterize polymetallic contaminations.

A new method is proposed to precisely and simultaneously quantify the exchangeable pool of metals in soils and to describe its reactivity at short- and long-term. It is based on multielementary Stable Isotopic Exchange Kinetics (multi-SIEK), first validated by a comparison between two monoelementary radioactive ((109)Cd*, (65)Zn*) IEK experiments, a mono- ((106)Cd) and multi- ((62)Ni, (65)Cu, (67)Zn, (106)Cd, (204)Pb) SIEK. These experiments were performed on a polluted soil located near the Zn smelter plant of Viviez (Lot watershed, France). The IEK results obtained for Cd and Zn were consistent across the experiments. (109)Cd*, (65)Zn* IEK, and multi-SIEK were then applied on 3 non- and moderate impacted soils that also provided consistent results for Cd and Zn. Within these experimental conditions, it can be concluded that no competition occurs between Cd, Zn, and the other metals during SIEK. Multi-SIEK results indicate that the isotopically exchangeable pool of Ni, Zn, and Cu are small (E(Ni), E(Zn), and E(Cu) values up to 17%) whatever the pollution degree of the soils considered in this study and whatever the duration of the interaction. On the contrary, Cd displays the highest E values (from 35% to 61% after 1 week), and E(Pb) displays a maximum value of 26% after 1 week. The multi-SIEK provides useful information on metal sources and reactivity relationship. Ni would be located in stable pedogenic phases according to its very low enrichment factor. The low E(Zn) and E(Cu) are consistent with location of Zn and Cu in stable phases coming from tailings erosion. Though Pb enrichments in soils may also be attributed to tailings particles, its larger exchangeable pool suggests that the Pb-bearing phases are more labile than those containing Zn and Cu. The high mobility of Cd in upstream soils indicates that it has been mostly emitted as reactive atmospheric particles during high temperature ore-treatment.

Reliability of transcutaneous oxygen tension measurement on the back of the hand and complex regional pain syndrome after stroke.

OBJECTIVE: To verify the reproducibility of measurement of transcutaneous oxygen tension (TcPo(2)) on the back of the hand in control subjects and stroke patients in the assessment of the complex regional pain syndrome type I (CRPS I). DESIGN: Case series study. SETTING: Physical medicine and rehabilitation department at a university hospital. PARTICIPANTS: Eighteen control subjects, 30 stroke patients without CRPS I, and 12 stroke patients with CRPS I. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: TcPo(2) was measured on the back of hands on 2 consecutive days using a polarographic technique. The reproducibility was evaluated by using the intraclass correlation coefficient (ICC) and the coefficient of variation. RESULTS: In the controls, the values of TcPo(2) were not reproducible, with an ICC of.51 (95% confidence interval [CI],.23-.72). Similarly, in the hemiplegics with and without CRPS I, TcPo(2) was not reproducible, with an ICC of.43 (95% CI, -.15 to.74) and.69 (95% CI,.45-.84), respectively. The differences between the 2 upper limbs were even less reproducible in each population. CONCLUSIONS: Measurement of TcPo(2) on the hand using our procedure did not seem to be sufficiently reproducible for application to a pathology such as CRPS I.

Clinical factors in the prognosis of complex regional pain syndrome type I after stroke: a prospective study.

OBJECTIVE: To evaluate clinical prognostic factors of complex regional pain syndrome type I (CRPS I) in patients with stroke in an attempt to improve the Perrigot score, which does not include shoulder subluxation, unilateral neglect, or depression. DESIGN: This was a prospective study. The initial clinical data (first month) included motor index, Ashworth scale, de Bats score for shoulder subluxation, Montgomery-Asberg Depression Rating Scale, and sensory disorders evaluation. The prognosis of CRPS I was evaluated from the Perrigot score. A score of CRPS I severity was measured on entry and 3 mo later. RESULTS: Of the 71 patients with hemiplegia who were included, 34.8% had a CRPS I. The five main clinical factors in the prognosis of CRPS I were motor deficit, spasticity, sensory deficits, and initial coma. The prognostic score of Perrigot was strongly correlated with the CRPS I severity and was predictive of subsequent progression. CONCLUSION: Shoulder subluxation, unilateral neglect, and depression did not seem to be determinant predictive factors of CRPS I severity.