The risk of overestimating the risk-metal leaching to groundwater near contaminated glass waste deposits and exposure via drinking water

Temporal risk assessment - 20th century Pb emissions to air and exposure via inhalation in the Swedish glass district

The objective of the present study was to assess historical emissions of Pb to air around a number of glassworks sites in southeastern Sweden, and the possible implications for human exposure. To do so, a four-step method was applied. First, emissions of Pb to air around 10 glassworks were modelled for the 20th century. Second, an assessment of the resulting exposure was made for a number of scenarios. Third, the number of people potentially exposed at different times was estimated, and fourth, measurements of "current" Pb concentrations in PM₁₀ material from four sites were conducted in 2019. The results show that the highest emissions, and exposures, occurred from 1970 to1980. It coincides with the time period when the highest number of people resided in the villages. At this time, the average Pb concentration in air around the six largest factories was about 2.4 μg Pb/m³, i.e. 16 times the present US national ambient air quality standard (NAAQS) of 0.15 μg Pb/m³. By year 2000 the modelled average concentration had dropped to 0.05 μg Pb/m³, a level that is normal for urban regions today. The PM₁₀ measurements from 2019 indicate a further decline, now with a mean value of about 0.02 μg Pb/m³. Over the entire study period, inhalation hazard quotients (HQs) exceeded the dietary HQ by many orders of magnitude, indicating that inhalation has been the most prevalent exposure pathway in the past. At present, both pathways are judged to be associated with low exposures. Even if only roughly approximated, a picture of the historical exposure can increase our understanding of the connection between exposure and disease, and can be valuable when risks are to be communicated to residents near contaminated areas.

Framework for preliminary risk assessment of brownfield sites

The complexity of hazards, risk and environmental legislation surrounding the reuse of brownfield sites necessitates a preliminary risk assessment prior to their redevelopment. Most prevailing efforts have been targeted at indepth site investigations, which are often costly, time-consuming, and may not be required at the early stages of a site development. However, there is a collective absence of knowledge, methods and computer models that can present a complete framework to carry out a preliminary risk assessment that is simpler, quicker and sufficient, not only for risk assessor but also effectively communicative for a diverse range of stakeholders with or without risk assessment expertise. Therefore, this study aims to bridge this gap by designing and creating a framework, by not only identifying hazards but also exposing the degree of presence. Sixty-five potential hazards have been identified from a comprehensive literature review. A questionnaire survey was then shared with brownfield site experts (n = 76) that asked then to rank the priority of the potential hazards. Kendall's W test and Kruskal-Wallis H test were subsequently conducted to determine the level of agreement among the respondents. Mean weightings were calculated by using the Voting Analytic Hierarchy Process (VAHP) to prioritize the potential hazards from 'more likely' to 'least likely'. Based on this information, the framework has been developed. It is anticipated that the framework can assist professionals to conduct a preliminary assessment of brownfield sites, which enables them to gain informative and rapid guidance on any potential liabilities or risks related to a site's suitability for acquisition or redevelopment. In this context, the framework outlines a systematic structure to collect appropriate data and information in the three main categories which are sources, pathways and receptors.

Lethal and long-term effects of landfill leachate on Eisenia andrei earthworms: Behavior, reproduction and risk assessment

Leachate is difficult to biodegrade, and presents variable physical, chemical and biological characteristics, as well as high toxicological potential for soil, groundwater and water bodies. In this context, untreated leachate toxicity was evaluated through acute and chronic exposures in Eisenia andrei earthworms. Physico-chemical leachate characterizations indicate a complex composition, with high organic matter (COD - 10,634 mg L^-1) and ammoniacal nitrogen (2388 mg L^-1) concentrations. Metals with carcinogenic potential, such as Cr, As and Pb, were present at 0.60, 0.14 and 0.01 μg L^-1, respectively and endocrine disrupting compounds were detected in estradiol equivalents of 660 ± 50 ng L^-1. Acute tests with Eisenia andrei indicated an LC₅₀ (72 h) of 1.3 ± 0.1 μL cm^-2 in a filter paper contact test and 53.9 ± 1.3 mL kg^-1 in natural soil (14 days). The EC₅₀ in a behavioral test was estimated as 31.6 ± 6.8 mL kg^-1, indicating an escape effect for concentrations ranging from 35.0 to 70.0 mL kg^-1 and habitat loss from 87.5 mL kg^-1 of leachate exposure. Chronic exposure (56 days) led to reproduction effects, resulting in a 4-fold decreased cocoon production and 7-fold juvenile decrease. This effect was mainly attributed to the possible presence of endocrine disrupting compounds. An estimated NOAEL of 1.7 mL L^-1 and LOAEL of 3.5 mL L^-1 were estimated for earthworms exposed to the assessed effluent. Extremely high-risk quotients (RQ ≥ 1) were estimated based on leachate application in irrigation. Thus, adequate municipal solid waste management is paramount, especially with regard to generated by-products, which can result in high toxicological risks for terrestrial organisms.

Proposal of new distribution coefficients (Kd) of potentially toxic elements in soils for improving environmental risk assessment in the State of São Paulo, southeastern Brazil

Soil solid-solution distribution coefficients (K_d) are used in predictive environmental models to assess public health risks. This study was undertaken to determine K_d for potentially toxic elements (PTE) Cd, Co, Cr, Cu, Ni, Pb, and Zn in topsoil samples (0-20 cm) from 30 soils in the State of São Paulo, southeastern Brazil. Batch sorption experiments were carried out, and PTE concentrations in the equilibrium solution were determined by High Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICPMS). Sorption data was fitted to the Freundlich model. The K_d values were either obtained directly from the slope coefficients of C-type isotherms or derived from the slope of the straight line tangent to the non-linear L-type and H-type isotherms. Stepwise multiple regression models were used to estimate the K_d values through the combined effect of a number of soil attributes [pH_H2O, effective cation exchange capacity (ECEC) and contents of clay, organic carbon, and Fe (oxy)hydroxides]. The smallest variation in K_d values was recorded for Cu (105-4598 L kg^-1), Pb (121-7020 L kg^-1), Ni (6-998 L kg^-1), as variation across four orders of magnitude was observed for Cd (7-14,339 L kg^-1), Co (2-34,473 L kg^-1), and Cr (1-21,267 L kg^-1). The K_d values for Zn were between 5 and 123,849 L kg^-1. According to median values of K_d, PTE were sorbed in the following preferential order: Pb > Cu > Cd > Ni > Zn > Cr > Co. The K_d values were best predicted using metal-specific and highly significant (p < 0.001) linear regressions that included pH_H2O, ECEC, and clay contents. The K_d values reported in this study are a novel result that can help minimize erroneous estimates and improve both environmental and public health risk assessments under humid tropical edaphoclimatic conditions.

Identifying dust as the dominant source of exposure to heavy metals for residents around battery factories in the Battery Industrial Capital of China

Heavy metals (HMs) are constantly released into the environment during the production and use of batteries. Battery manufacturing has been ongoing for over six decades in the "Battery Industrial Capital" (located in Xinxiang City) of China, but the potential exposure pathways of residents in this region to HMs remain unclear. To clarify the exposure pathways and health risk of human exposure to HMs, hand wipe samples (n=82) and fingernail samples (n=36) were collected from residents (including young children (0-6 years old), children (7-12 years old) and adults (30-60 years old)) living around battery factories. The total concentrations of the target HMs (Zn, Mn, Cu, Pb, Ni, Cr, Cd, Co) in hand wipes ranged from 133 to 8040 μg/m², and those in fingernails ranged from 9.7-566 μg/g. HM levels in the hand wipe and fingernail samples both decreased with age, and higher HM levels were observed for males than females. The HM composition profiles in these two matrices represented a high degree of similarity, with Zn as the predominant element, and thus, oral ingestion and dermal exposure via dust were expected to be the most important HM exposure pathways for residents in this region. The non-carcinogenic risks (HQs) from dermal and oral ingestion exposure to Cd, Cr, and Pb were higher than those of the other five elements for all three populations, and the HQ_derm of Cd for young children was 2.1 (HQ_oral=0.6). Moreover, the hazard index (HI) values of ∑₈HMs for young children (HI_total=5.2, HI_oral=2.0, HI_dermal=3.2) and children (HI_total=1.6, HI_oral=1.3, HI_dermal=0.3) exceeded the safe threshold (1.0). Therefore, young children and children should be prioritized for protection from HM pollution, and more attention should be paid to young children's dermal exposure to Cd in this region.

Assessment of elements mobility in anthropogenic layer of historical wastes related to glass production in Izera Mountains (SW Poland)

A geophysical survey conducted in the remote forest glade, located in the Izery Mountains (SW Poland), revealed the existence of an anthropogenic layer of historical glass wastes dumped in this area during the activity of a glass factory in the 18th and 19th centuries and domestic wastes dumped during the second part of the 20th century. The aim of the study was assessment of potential ecological risk related to the release of potentially toxic elements to the soil, groundwater and surface waters. The assessment was done on the base of classical geochemical analysis supported by calculation of environmental indices as well as on mobility of elements (leaching test and BCR sequential extraction). As an innovative aspect in the geostatistical interpretation of the data, some magnetic parameters (magnetic susceptibility-χ, χ/Fe ratio) were also used. It allowed for a better understanding of the relationship of PTEs with various forms of iron. The BCR sequential extraction found that among the PTEs, only Zn (up to 43%) was in a potentially mobile fraction probably occurring in ionic form, associated with iron oxides only by surface adsorption forces. The leaching has shown a slight increase in Zn and Cu content in the surface waters; however, it was not considered to be a real ecological threat because the pH of the waste material and soil cover is >6.0 and the scenario of a radical decrease in pH is rather unrealistic. The other PTEs were associated with more stable E2, E3 and E4 fractions. Zinc, similar to Ni, Co and Cu in waste samples, was highly correlated with magnetic parameters (χ and χ/Fe). It means that a considerable part of these metals was associated with ferrimagnetic iron oxides, although they can also occur in the form of inclusions in aluminosilicates and enclosed in glassy phases.

Failure of generic risk assessment model framework to predict groundwater pollution risk at hundreds of metal contaminated sites: Implications for research needs

Soil pollution constitutes one of the major threats to public health, where spreading to groundwater is one of several critical aspects. In most internationally adopted frameworks for routine risk assessments of contaminated land, generic models and soil guideline values are cornerstones. In order to protect the groundwater at contaminated sites, a common practice worldwide today is to depart from health risk-based limit concentrations for groundwater, and use generic soil-to-groundwater spreading models to back-calculate corresponding equilibrium levels (concentration limits) in soil, which must not be exceeded at the site. This study presents an extensive survey of how actual soil and groundwater concentrations, compiled for all high-priority contaminated sites in Sweden, relate to the national model for risk management of contaminated sites, with focus on As, Cu, Pb and Zn. Results show that soil metal concentrations, as well as total amounts, constitute a poor basis for assessing groundwater contamination status. The evaluated model was essentially incapable of predicting groundwater contamination (i.e. concentrations above limit values) based on soil data, and erred on the "unsafe side" in a significant number of cases, with modelled correlations not being conservative enough. Further, the risk of groundwater contamination was almost entirely independent of industry type. In essence, since neither soil contaminant loads nor industry type is conclusive, there is a need for a supportive framework for assessing metal spreading to groundwater accounting for site-specific, geochemical conditions.

Exposure of metals and PAH through local foods and risk of cancer in a historically contaminated glassworks area

BACKGROUND

Production of crystal glass and colored art glassware have been going on in the south-eastern part of Sweden since the 1700s, at over 100 glassworks and smaller glass blowing facilities, resulting in environmental contamination with mainly arsenic (As), cadmium (Cd), lead (Pb) and polycyclic hydrocarbons (PAH). High levels of metals have been found in soil, and moderately elevated levels in vegetables, mushrooms and berries collected around the glassworks sites compared with reference areas. Food in general, is the major exposure source to metals, such as Cd and Pb, and PAHs. Exposure to these toxic metals and PAH has been associated with a variety of adverse health effects in humans including cancer.

OBJECTIVE

The aim of the present study was to evaluate the occurrence of cancer in a cohort from the contaminated glasswork area in relation to long-term dietary intake of locally produced foods, while taking into account residential, occupational and life styles factors.

METHODS

The study population was extracted from a population cohort of 34,266 individuals who, at some time between the years 1979-2004, lived within a 2 km radius of a glassworks or glass landfill. Register information on cancer incidence and questionnaire information on consumption of local foods (reflecting 30 years general eating habits), life-time residence in the area, life style factors and occupational exposure was collected. Furthermore, blood (n = 660) and urine (n = 400) samples were collected in a subsample of the population to explore associations between local food consumption frequencies, biomarker concentrations in blood (Cd, Pb, As) and urine (PAH metabolite 1-OHPy) as well as environmental and lifestyle factors. The concurrent exposure to persistent organic pollutants (POPs) from food was also considered. A case-control study was performed for evaluation of associations between intakes of local food and risk of cancer.

RESULTS

Despite high environmental levels of Cd, Pb and As at glasswork sites and landfills, current metal exposure in the population living in the surrounding areas was similar or only moderately higher in our study population compared to the general population. Reported high consumption of certain local foods was associated with higher Cd and Pb, but not As, concentrations in blood, and 1-OHPy in urine. An increased risk of cancer was associated with smoking, family history of cancer, obesity, and residence in glasswork area before age 5 years. Also, a long-term high consumption of local foods (reflecting 30 years general eating habits), i.e. fish and meat (game, chicken, lamb), was associated with increased risk of various cancer forms.

CONCLUSIONS

The associations between consumption of local food and different types of cancer may reflect a higher contaminant exposure in the past, and thus, if consumption of local food contributes to the risk of acquiring cancer, that contribution is probably lower today than before. Furthermore, it cannot be ruled out that other contaminants in the food contribute to the increased cancer risks observed.

Multiple exposure pathways and health risk assessment of heavy metal(loid)s for children living in fourth-tier cities in Hubei Province

In the past, most research focused on the children living near a typical contaminated area but ignored the health risks of children living in the fourth or fifth tier cities without typical contaminated sources. These cities are now facing a series of problems, such as serious environmental pollution, undeveloped health system and so on. Furthermore, the development of modern logistics for food delivery has altered lifestyles that directly impact diets and eating patterns. In this study, multiple exposure pathways and health risks of children to heavy metal(loid)s were studied based on questionnaire-based surveys and field sampling of soil, dust, fine particulates, drinking water and food. We found that Pb, Cd and Mn levels in environmental samples were very high indicating a serious pollution problem. Inhalation exposure via aerosol particles was the most important pathway and was greater than exposure by food ingestion. The hazard index for Mn via aerosol particles was >1 even at the 5th percentile and Mn levels in urine was 10 times higher than those of people living in typical contaminated areas. The total incremental lifetime cancer risk (ILCR) for all metal(loid)s was also higher than the threshold at the 95th percentile. This study highlights health risks to children living in fourth tier cities and the importance of air pollution control to protect heavy metal exposure for children.

Short-term geochemical investigation and assessment of dissolved elements from simulated ash reclaimed soil into groundwater

A soil column migration trough was used to study the leaching behavior and geochemical partitioning of fifteen elements Al, As, Cr, Cu, Fe, Mg, Sn, Sb, Zn, V, Co, Mn, Pb, Ni and Cd in simulated ash reclaimed soil. According to the results of cluster analysis for the sampling stations, there were three clusters: Cluster 1 of 7 wells with relative good groundwater quality originated from the background control area, Cluster 2 of 9 wells with worst groundwater quality in the downstream parts of the simulated ash reclaimed soil, and Cluster 3 of 2 wells with representative of samples influenced by the combined effect of injection of leaching solution and the main current. Statistical analysis identified five factor types that accounted for 83.055% of the total variance, which declined in the order: ash-soil rate > leaching intensity > water depths > flow velocity > leaching time. As, Sb, Cd, Pb and Ni were the dominant contaminants. The water around ash reclaimed soil was unsuitable for drinking. As, Mn, Cd, Sb, Co and V were the largest contributors to health risks. Soils reclaimed with fly ash can consequently be a long-time source for the transfer of toxic elements into groundwater.

Chemical extraction of trace elements from hazardous fine fraction at an old glasswork dump

Old glassworks sites have been always associated with contamination by different trace elements like Pb, Cd, As, Zn and others. The mixture of soil and waste glass of particle sizes <2 mm at one of the oldest Swedish glassworks (the Pukeberg) was studied by analyzing the trace elements content, organic content (3.6%) and pH (7.4). The results showed hazardous concentrations of Pb (1525 mg/kg), Ba (1312 mg/kg), Sb (128 mg/kg), Cd (36 mg/kg), As (118 mg/kg), Zn (1154 mg/kg) and Co (263 mg/kg) exceeded the Swedish guidelines of contaminated soil. Batch chemical extraction by the chelating agents EDTA, DTPA and the biodegradable NTA were performed to study the effect of chelating agent concentration and mixing time on the extraction efficiencies by following a Box-Wilson design of experiments. The results displayed good extraction efficiencies (less than 41%) of Pb, Cd, As and Zn by the EDTA, DTPA and NTA, which seemed depends on the type of chelator. In addition, high correlation between the extraction efficiencies, the chelators concentration and mixing time was found based on the statistical and experimental results.

A review of contamination of surface-, ground-, and drinking water in Sweden by perfluoroalkyl and polyfluoroalkyl substances (PFASs)

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are found in aquatic systems, flora, and fauna worldwide. These potentially harmful compounds are also frequently detected in Sweden and have already resulted in severe problems for public drinking water supply, i.e., some wells had to be closed due to high PFAS concentrations both in raw water and produced drinking water. Knowledge on PFAS occurrence in Sweden is still quite low, although monitoring is currently ongoing. This work describes potential sources for PFASs to enter the drinking water supply in Sweden and compares different occurrences of PFASs in raw and drinking water in the country. Moreover, the monitoring history, the legal situation, and remediation actions taken are presented. Finally, future challenges and the way forward in Sweden are discussed.