Insights of Pb isotopic signature into the historical evolution and sources of Pb contamination in a sediment core of the southwestern Iberian Atlantic shelf

Multi-isotope signatures (Cu, Zn, Pb) of different particle sizes in road-deposited sediments: a case study from industrial area

Road-deposited sediments (RDS) are major sources of heavy metal contamination in urban areas and adversely affect surrounding environments and human health. Multi-isotope combinations (Cu, Zn, and Pb), which serve as environmental tracers, enable the identification and management of metal contaminants in RDS. Here, we present Cu, Zn, and Pb isotopic data for the first time in size-fractionated RDS samples collected from industrial areas to describe the relationship between the RDS and total suspended solids (TSS) in runoff, and to explore the feasibility of using multi-isotopes to identify sources of metal contamination. RDS in the industrial study areas had high concentrations of Cu, Zn, and Pb, and their δ65CuAE647, δ66ZnIRMM3702, and 206Pb/207Pb values ranged from − 0.33 to + 0.73‰, − 0.36 to + 0.01‰, and 1.1418 to 1.1616, respectively. The variation in δ65CuAE647 (δ65Cumax-min) was larger than that of δ66ZnIRMM3702 (i.e., δ66Znmax-min), and the isotope values of Zn and Pb (206Pb/207Pb) tended to increase with the concentrations of these elements. Meanwhile, the fine RDS particles (< 63 µm) had similar Cu, Zn, and Pb isotopic compositions to those of TSS. Hierarchical cluster analyses revealed that the < 63 µm RDS fractions were associated with the TSS. Our results also showed that a combination of Pb and either Cu or Zn could be used to distinguish between RDS and non-exhaust emissions (e.g., brake pads, tires, etc.). Multi-isotope approaches utilizing Cu, Zn, and Pb and more robust isotopic data on individual sources of metal contamination could be useful for identifying pollution sources and understanding their environmental impacts.

Recent and historical pollution legacy in high altitude Lake Marboré (Central Pyrenees): A record of mining and smelting since pre-Roman times in the Iberian Peninsula

We have analyzed potential harmful trace elements (PHTE; Pb, Hg, Zn, As and Cu) on sediment cores retrieved from lake Marboré (LM) (2612 m a.s.l, 42°41'N; 0° 2'E). PHTE variability allowed us to reconstruct the timing and magnitude of trace metal pollutants fluxes over the last 3000 years in the Central Pyrenees. A statistical treatment of the dataset (PCA) enabled us to discern the depositional processes of PHTE, that reach the lake via direct atmospheric deposition. Indeed, the location of LM above the atmospheric boundary layer makes this lake an exceptional site to record the long-range transport of atmospheric pollutants in the free troposphere. Air masses back-trajectories analyses enabled us to understand the transport pathways of atmospheric pollutants while lead isotopic analyses contributed to evaluate the source areas of metal pollution in SW Europe during the Late Holocene. PHTE variability, shows a clear agreement with the main exploitation phases of metal resources in Southern Europe during the Pre-Industrial Period. We observed an abrupt lead enrichment from 20 to 375 yrs CE mostly associated to silver and lead mining and smelting practices in Southern Iberia during the Roman Empire. This geochemical data suggests that regional atmospheric metal pollution during the Roman times rivalled the Industrial Period. PHTE also increased during the High and Late Middle Ages (10-15^th centuries) associated to a reactivation of mining and metallurgy activities in high altitude Pyrenean mining sites during climate amelioration phases. Atmospheric mercury deposition in the Lake Marboré record mostly reflects global emissions, particularly from Almadén mines (central Spain) and slightly fluctuates during the last three millennia with a significant increase during the last five centuries. Our findings reveal a strong mining-related pollution legacy in alpine lakes and watersheds that needs to be considered in management plans for mountain ecosystems as global warming and human pressure effects may contribute to their future degradation.

Insights into leaded gasoline registered in mud depocenters derived from multivariate statistical tool: southeastern Brazilian coast

Lead has been widely used since antiquity, but its uses drastically increased during the Industrial Revolution. The global emission of Pb into the environment was mainly due to tetraethyl lead added to gasoline as an antiknock additive. Because of its toxicity and neurological effects, the compound was phased out in the 1980s. Isotopic signatures are widely applied to differentiate sources of Pb; however, this is an expensive and sophisticated analysis compared to elemental analysis. Thus, this study aims to gain insight into leaded gasoline registered in mud depocenters from the southeastern Brazilian coast using multivariate statistical tools on elemental analysis data of trace elements. Seven multiple cores were collected on board the Research Vessel Alpha Crucis. Al, As, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, Sc, Sr, V and Zn were analyzed by acid digestion and quantified by ICP-OES. Levels and enrichment factors of Pb resulted in homogeneous columns, indicating that small variations in concentrations can be attributed to grain size differences, not presenting contaminated levels. From statistical results, the highest contribution on the first component was represented by a lithogenic source with the leaching of continental rocks. Lead content was notable in its high loadings in other components, which suggests atmospheric deposition. An increase in these components in subsurface samples from vertical profiles between 1935 and 1996 could represent a fingerprint of the consumption of leaded gasoline in Brazil between 1923 and 1989. Thus, statistical analysis of elemental data enabled to infer possible sources and pathways of Pb to the environment, without isotopic analysis.

Evidence for the onset of mining activities during the 13th century in Poland using lead isotopes from lake sediment cores

Efforts to study how human activities have influenced the environment since the end of the Roman period to present day are lacking for North Central Europe. Here, we present new lead (Pb) isotope data determined from two sediment cores collected from ancient lakes spanning the last 1500 years, located in the Kuyavian-Pomeranian Voivodeship, Poland. Study sites at Radzyń Chełmiński and Rywałd were used to differentiate Pb sources. Radzyń Chełmiński is located in the vicinity of a late Medieval Teutonic Order castle and town, while Rywałd is situated within a relatively pristine area until the 19th century when it became used for agricultural purpose. Core samples were analyzed for Pb concentration and isotopes (²⁰⁶Pb, ²⁰⁷Pb, ²⁰⁸Pb). Bayesian modeling was used to isolate the anthropogenic signal at each site over time. For both sites, Pb enrichment factors relative to titanium (Ti) and upper continental crust values range from 13 to 159. Lead isotopic ratios range from background, pre-anthropogenic local values (²⁰⁶Pb/²⁰⁷Pb = 1.31 ± 0.03‰, ²⁰⁸Pb/²⁰⁶Pb = 1.97 ± 0.04‰) to anthropogenic values (SW Poland coal, ore, slag ²⁰⁶Pb/²⁰⁷Pb = 1.17 ± 0.01‰, ²⁰⁸Pb/²⁰⁶Pb = 2.09 ± 0.01‰). Modeled anthropogenic contribution varies greatly over time, ranging from 14 to 100%. At Radzyń Chełmiński, modeled anthropogenic Pb contribution and measured Pb concentration follow similar trends. However, at Rywałd, from around A.D.1000 to 1400 CE these profiles diverge significantly. Our new insights highlight different sources of Pb from the 12th century to present day: (1) short range agricultural activities from the town, and (2) long range mining activities. Additionally, prior to the 12th century, our data suggest continental anthropogenic activity possibly favored by a warmer climate.

First assessment on trace elements in sediment cores from Namibian coast and pollution sources evaluation

Trace elements (TEs), Rare Earth Elements (REEs) and Pb isotope ratios were determined in six small cores sampled along the Namibian coast and different indices, such as Enrichment Factor, Geo-accumulation Index and Pollution load index, were calculated to evaluate possible metal contamination in the area. Concentrations of Pb, Cu, As and Cd were strongly enhanced at the upper 7 cm of core C5, which is located at Walvis Bay, at the major harbor and urban/industrial center of Namibia, indicating the impact from the recent anthropogenic activities. Principal Component Analysis was applied to the data set indicating possible common sources of the contaminants. Pb stable isotope ratios, combined with the dating of core C5 at Walvis Bay, further confirmed the anthropogenic provenance of Pb sources in the recent sediment deposits, which occurred after 1945, when the anthropogenic activities in the area began to increase. REEs profiles were also determined, showing enrichment in REEs for some of the samples, typical for the minerals present in the area. Ce anomaly was detected in one of the cores but the REEs profile did not reveal anomalies ascribable to anthropogenic influence.

Temporal metal concentration in coastal sediment at the north region of Persian Gulf

The purpose of this article is to study, result of metal concentration in two-sediment cores from Persian Gulf. Age of sediment is determined by C¹⁴ isotope method and bulk concentration is determined by ICP. This research output shows that, age of BandareAbbas core back to 9660 and Bushehr core to 15,600 years ago. Also,concentration in BandareAbbas and Bushehr cores respectively change as, As (1.08-11.76 Vs 5.2-13.09), Ba (15.03-129.5 Vs 73.9-120.4), Cd (0.09-0.46 Vs 0.09-0.18), Li (5.66-58.5 Vs 15.3-33.4), Mo (0.3-0.75 Vs 0.3-0.8), Mg (7928.4-15,503.9 Vs 13,102.8-17,227.8), Mn (110.6-566.4 Vs 279.3-429.1), Na (8905.47-27,993.3 Vs 9357.7-27,541.4), Ni (13.3-110.3 Vs 37.1-88.4), Pb (0.5-42.5 Vs 2.5-13.6), Sr (407.5-1773.2 Vs 440.3-1596.9), Zn (13.05-71.2Vs22.4-50.5), Fe (0.46-4.07 Vs 1.7-3.18), Ca (9.25-23.3 Vs 13.8-19.2) and Al (0.62-8.15 Vs 2.48-4.65). Moreover different pollution index investigation represent that except Ca, the rest of the metal elements do not show pollution.

Lead isotopic fingerprint in human scalp hair: The case study of Iglesias mining district (Sardinia, Italy)

The Sulcis-Iglesiente district (SW Sardinia, Italy) has been, until recently, one of the most important Italian polymetallic mining areas for the extraction of lead. Epidemiological studies conducted over several decades have indicated this site at high risk of environmental crisis with possible adverse effects on the public health. In the present paper we discuss Pb isotope signatures in human scalp hair and road dust collected from the Sulcis-Iglesiente area in order to trace the exposure of populations to potential Pb sources. A total of 23 determinations (20 on hair samples and 3 on road dust samples) of lead isotope ratios (²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb) were carried out. The obtained results were integrate with literature data regarding the total content of Pb in hair samples from the same study area. Hair from children living in Sant'Antioco exhibited lead isotope ratios in the ranges 1.152-1.165 for ²⁰⁶Pb/²⁰⁷Pb and 2.101-2.108 for ²⁰⁸Pb/²⁰⁶Pb, while hair samples from Iglesias resulted less radiogenic: ²⁰⁶Pb/²⁰⁷Pb~1.147-1.154 and ²⁰⁸Pb/²⁰⁶Pb~2.106-2.118. These values pointed to a multi-source mixing between the less radiogenic sources, corresponding to the Pb ore deposits, and the more radiogenic sources identified in local background.