Cancer Mortality in Residents of the Cadmium-Polluted Jinzu River Basin in Toyama, Japan

Risk of prostate cancer in the proximity of industrial installations: A multicase-control study in Spain (MCC-Spain)

BACKGROUND

Prostate cancer (PC) is the second most frequent tumor in men worldwide; however, its etiology remains largely unknown, with the exception of age and family history. The wide variability in incidence/mortality across countries suggests a certain role for environmental exposures that has not yet been clarified.

OBJECTIVE

To evaluate the association between risk of PC (by clinical profile) and residential proximity to pollutant industrial installations (by industrial groups, groups of carcinogens, and specific pollutants released), within the context of a Spanish population-based multicase-control study of incident cancer (MCC-Spain).

METHODS

This study included 1186 controls and 234 PC cases, frequency matched by age and province of residence. Distances from participants' residences to the 58 industries located in the study area were calculated and categorized into "near" (considering different limits between ≤1 km and ≤ 3 km) or "far" (>3 km). Odds ratios (ORs) and 95 % confidence intervals (95%CIs) were estimated using mixed and multinomial logistic regression models, adjusted for potential confounders and matching variables.

RESULTS

No excess risk was detected near the overall industries, with ORs ranging from 0.66 (≤2 km) to 1.11 (≤1 km). However, positive associations (OR; 95%CI) were found, by industrial group, near (≤3 km) industries of ceramic (2.54; 1.28-5.07), food/beverage (2.18; 1.32-3.62), and disposal/recycling of animal waste (2.67; 1.12-6.37); and, by specific pollutant, near plants releasing fluorine (4.65; 1.45-14.91 at ≤1.5 km) and chlorine (5.21; 1.56-17.35 at ≤1 km). In contrast, inverse associations were detected near industries releasing ammonia, methane, dioxins+furans, polycyclic aromatic hydrocarbons, trichloroethylene, and vanadium to air.

CONCLUSIONS

The results suggest no association between risk of PC and proximity to the overall industrial installations. However, some both positive and inverse associations were detected near certain industrial groups and industries emitting specific pollutants.

Lead, Mercury, and Cadmium Concentrations in Blood Products Transfused to Neonates: Elimination Not Just Mitigation

Lead (Pb), mercury (Hg), and cadmium (Cd) are identified as potent developmental neurotoxicants. Neonates are the main group receiving multiple blood transfusions. The exposure of neonates to these heavy metals (HMs) can occur through blood transfusions. This study aimed to determine the concentrations of lead (Pb), mercury (Hg), and cadmium (Cd) in various blood products (plasma, platelets, packed red blood cells (pRBCs), and whole blood (WB)) to explore the probability of concurrent exposure of these HMs and to identify the metal load per transfusion with risk assessment. Residual bloods from blood bank bags were collected after neonatal transfusion. Pb, Hg, and Cd concentrations were determined in 120 samples of blood products by inductively coupled plasma mass spectrometry (ICP-MS). Pb and Cd levels were over the normal levels in 19.2 and 5.9% of all blood units, respectively. In 35 and 0.8% of blood units, the Pb and Cd concentrations, respectively, were higher than that recommended for transfusions in premature neonates. The anticipated safe value was surpassed by 2.5% for Cd of all transfusions, primarily because of WB. However, Hg was detected only in 5.8% of all samples and their concentrations were within the normal range. The concurrent neonatal exposure to Pb, Hg, and Cd was statistically significant. Hazard quotients of Hg and Cr were >1 and Pb cancer risk was 2.41 × 10-4. To the best of our knowledge, this study is the first report examining Pb, Hg, and Cd in blood products other than WB and pRBCs using ICP-MS. This study demonstrated the exposure of neonates to Pb, Hg, and Cd during transfusion with a considerable amount of Pb. It confirms the significant concurrent exposure to the three HMs, which maximize their potential developmental neurotoxicity with a high probability of developing non-carcinogenic and carcinogenic health effects.

Exposure to environmental chemicals and cancer risk: epidemiological evidence from Japanese studies

Exposure to certain chemicals in the environment may contribute to the risk of developing cancer. Although cancer risk from environmental chemical exposure among general populations is considered low compared to that in occupational settings, many people may nevertheless be chronically exposed to relatively low levels of environmental chemicals which vary by such various factors as residential area, lifestyle, and dietary habits. It is therefore necessary to assess population-specific exposure levels and examine their association with cancer risk. Here, we reviewed epidemiological evidence on cancer risk and exposure to dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), polychlorinated biphenyls (PCBs), per- and polyfluoroalkyl substances (PFASs), cadmium, arsenic, and acrylamide. Japanese are widely exposed to these chemicals, mainly through the diet, and an association with increased cancer risk is suspected. Epidemiological evidence from Japanese studies to date does not support a positive association between blood concentrations of DDT, HCH, PCBs, and PFASs and risk of breast or prostate cancer. We established assessment methods for dietary intake of cadmium, arsenic, and acrylamide using a food frequency questionnaire. Overall, dietary intakes of cadmium, arsenic, and acrylamide were not significantly associated with increased risk of total cancer and major cancer sites in the Japan Public Health Center-based Prospective Study. However, statistically significant positive associations were observed between dietary cadmium intake and risk of estrogen receptor-positive breast cancer among postmenopausal women, and dietary arsenic intake and risk of lung cancer among male smokers. In addition, studies using biomarkers as exposure assessment revealed statistically significant positive associations between urinary cadmium concentration and risk of breast cancer, and between ratio of hemoglobin adducts of acrylamide and glycidamide and risk of breast cancer. Epidemiological studies of general populations in Japan are limited and further evidence is required. In particular, studies of the association of organochlorine and organofluorine compounds with risk of cancer sites other than breast and prostate cancer are warranted, as are large prospective studies of the association between biomarkers of exposure and risk of cancer.

The Effect of "Production during Remediation" of Plants in Cd-Contaminated Soil

In order to find suitable plants for "production during remediation" in wheat fields moderately contaminated by cadmium (Cd), five plants-green amaranth, oil sunflower, broomcorn, maize, and waxy maize-were planted in pots to study their enrichment characteristics and remediation effects in Cd-contaminated soil. The results showed that the highest bioaccumulation and translocation factors were greater than 0.5 for oil sunflower, which had the strongest Cd-enrichment ability in Cd-contaminated soil, but its biomass was small, and the Cd content of the grain exceeded the standard (GB2762-2017). The Cd content in the grains of broomcorn, maize, and waxy maize was less than 0.1 mg∙kg^-1, which is lower than the national food safety standard on limiting pollutants in food (GB2762-2017). Broomcorn accumulated 0.429 mg∙pot^-1 for Cd, with a Cd-extraction efficiency of 1.73%, which were higher than other plants. Taking the risk-screening values in GB15618-2018 "Soil Environmental Quality Standard" as the target, it will take 80 years to remediate using broomcorn, which has the highest extraction efficiency, based on cultivating remediation plants once per year. However, in view of the scarcity of arable land resources in China and the objective of safe production during remediation, the use of broomcorn can be considered for production during remediation for the given degree of Cd contamination of the soil.

Cadmium: A Focus on the Brown Crab (Cancer pagurus) Industry and Potential Human Health Risks

Cadmium is a major health risk globally and is usually associated with pollution and anthropogenic activity. The presence of cadmium in food is monitored to ensure that the health and safety of consumers are maintained. Cadmium is ubiquitous in the Asian and Western diets, with the highest levels present in grains, leafy greens, and shellfish. As part of their natural lifecycle of moulting and shell renewal, all crustaceans-including the brown crab (Cancer pagurus)-bioaccumulate cadmium from their environment in their hepatopancreas. The brown crab is an important species to the crab-fishing industries of many European countries, including Ireland. However, the industry has come under scrutiny in Europe due to the presence of cadmium in the brown crab meat intended for live export to Asia. This review explores evidence regarding the effects of cadmium consumption on human health, with a focus on the brown crab. Differences in cadmium surveillance have given rise to issues in the crab industry, with economic consequences for multiple countries. Currently, evidence suggests that brown crab consumption is safe for humans in moderation, but individuals who consume diets characterised by high levels of cadmium from multiple food groups should be mindful of their dietary choices.

Influence of the Levels of Arsenic, Cadmium, Mercury and Lead on Overall Survival in Lung Cancer

The effects of heavy metals on cancer risk have been widely studied in recent decades, but there is limited data on the effects of these elements on cancer survival. In this research, we examined whether blood concentrations of the heavy metals arsenic, cadmium, mercury and lead were associated with the overall survival of lung cancer patients. The study group consisted of 336 patients with lung cancer who were prospectively observed. Blood concentrations of heavy metals were measured to study the relationship between their levels and overall survival using Cox proportional hazards analysis. The hazard ratio of death from all causes was 0.99 (p = 0.94) for arsenic, 1.37 (p = 0.15) for cadmium, 1.55 (p = 0.04) for mercury, and 1.18 (p = 0.47) for lead in patients from the lowest concentration quartile, compared with those in the highest quartile. Among the patients with stage IA disease, this relationship was statistically significant (HR = 7.36; p < 0.01) for cadmium levels in the highest quartile (>1.97–7.77 µg/L) compared to quartile I (0.23–0.57 µg/L, reference). This study revealed that low blood cadmium levels <1.47 µg/L are probably associated with improved overall survival in treated patients with stage IA disease.

Co-exposures of TiO2 nanoparticles and cadmium ions at non-lethal doses aggravates liver injury in mice with ConA-induced hepatitis

The wide applications of titanium dioxide nanoparticles (TNP) and ubiquitous cadmium (Cd) pollution increase the chances of their co-existence in the environment and also pose potential health risks to humans. However, toxicological understanding of effects of co-exposures of TNP and Cd to mammals is still lacking. In this study, non-lethal doses of TNP and CdCl2 were intravenously co-administered to healthy or Concanavalin A (ConA)-induced acute hepatitis mice. Co-exposures of TNP and CdCl2 increased the accumulation of Cd2+ in the liver of hepatitis mice, which was 1.42-fold higher than that of healthy mice. Co-exposures also caused liver damage only in hepatitis mice on the basis of histopathological and biochemical evidence. Further study showed that co-exposure upregulated hepatic oxidative stress, which further induced autophagy and apoptosis only in the liver of hepatitis mice. This finding underlines the potential toxicological consequences of co-exposures of TNP and CdCl2 in hepatitis sufferers.

The Relationship between the Urinary Cadmium Concentration and Cause-Specific Mortality in Subjects without Severe Renal Damage: A 35-Year Follow-Up Study in a Cadmium-Polluted Area of Japan

We evaluated the association between urinary cadmium concentration (uCd, μg/g Cr) and risk of cause-specific mortality according to urinary β2-microglobulin (MG) concentration. Participants were 1383 male and 1700 female inhabitants of the Cd-polluted Kakehashi River basin. The uCd and β2-MG were evaluated in a survey in 1981–1982, where those participants were followed-up over 35 years later. Among the participants with a urinary β2-MG < 1000, the hazard ratios (HRs) (95% confidence interval) for mortality were significantly higher in those with a uCd of ≥10.0 compared with <5.0 for cardiovascular disease [HR 1.92 (1.08–3.40) for men, 1.71 (1.07–2.71) for women], pneumonia or influenza [2.10 (1.10–4.00) for men, 2.22 (1.17–4.19) for women], and digestive diseases [for men; 3.81 (1.49–9.74)]. The uCd was significantly associated with mortality from heart failure in women and digestive diseases in men, after adjustment for other causes of death using the Fine and Gray competing risk regression model. For participants with a urinary β2-MG of ≥1000, no significant association was observed between uCd and any major cause of death. In the absence of kidney damage, Cd may increase the risk of death from cardiovascular disease, pneumonia, and digestive diseases.

Cadmium and Lead Exposure, Nephrotoxicity, and Mortality

The present review aims to provide an update on health risks associated with the low-to-moderate levels of environmental cadmium (Cd) and lead (Pb) to which most populations are exposed. Epidemiological studies examining the adverse effects of coexposure to Cd and Pb have shown that Pb may enhance the nephrotoxicity of Cd and vice versa. Herein, the existing tolerable intake levels of Cd and Pb are discussed together with the conventional urinary Cd threshold limit of 5.24 μg/g creatinine. Dietary sources of Cd and Pb and the intake levels reported for average consumers in the U.S., Spain, Korea, Germany and China are summarized. The utility of urine, whole blood, plasma/serum, and erythrocytes to quantify exposure levels of Cd and Pb are discussed. Epidemiological studies that linked one of these measurements to risks of chronic kidney disease (CKD) and mortality from common ailments are reviewed. A Cd intake level of 23.2 μg/day, which is less than half the safe intake stated by the guidelines, may increase the risk of CKD by 73%, and urinary Cd levels one-tenth of the threshold limit, defined by excessive ß₂-microglobulin excretion, were associated with increased risk of CKD, mortality from heart disease, cancer of any site and Alzheimer's disease. These findings indicate that the current tolerable intake of Cd and the conventional urinary Cd threshold limit do not provide adequate health protection. Any excessive Cd excretion is probably indicative of tubular injury. In light of the evolving realization of the interaction between Cd and Pb, actions to minimize environmental exposure to these toxic metals are imperative.

An assessment of sensitivity biomarkers for urinary cadmium burden

BACKGROUND

Excess cadmium (Cd) intake poses a general risk to health and to the kidneys in particular. Among indices of renal dysfunction under Cd burden measures are the urinary N-acetyl-β-D-glucosidase (UNAG) and urinary β2-microglobulin (Uβ2-MG) enzymes. However, the end-pointed values and the Cd burden threshold remain controversial because the scopes fluctuate widely.

METHODS

To ascertain the clinical benchmark dose of urinary Cd (UCd) burden for renal dysfunction, 1595 residents near a Cd site were surveyed. Urine was sampled and assayed. A benchmark dose low (BMDL) was obtained by fitting UCd levels and index levels.

RESULTS

We found that over 50% of the subjects were suffering from Cd exposure as their UCd levels far exceeded the national standard threshold of 5.000 μg/g creatinine (cr). Further analysis indicated that Uβ2-MG was more sensitive than UNAG for renal dysfunction. The BMDL for UCd was estimated as 3.486 U/g cr (male, where U is unit of enzyme) and 2.998 U/g cr (female) for UNAG. The BMDL for Uβ2-MG, which is released into urine from glomerulus after Cd exposure, was found to be 2.506 μg/g cr (male, where μg is the unit of microglobulin) and 2.236 μg/g cr (female).

CONCLUSIONS

Uβ2-MG is recommended as the sensitivity index for renal dysfunction, with 2.2 μg/g cr as the threshold for clinical diagnosis. Our findings suggest that Uβ2-MG is the better biomarker for exposure to Cd.

Relationship between urinary β2 -microglobulin concentration and mortality in a cadmium-polluted area in Japan: A 35-year follow-up study

The relationship between urinary β₂ -microglobulin (β₂ -MG) and the risk of all-cause mortality and cause-specific mortality in a cadmium (Cd)-polluted area was investigated in 3139 inhabitants (1404 men and 1735 women) of the Kakehashi River basin in Japan at 35-year follow-up. The subjects had been participants in the 1981-1982 health impact survey that assessed Cd-induced renal dysfunction, as measured by the urinary β₂ -MG concentration. Hazard ratios were calculated to assess the risk of all-cause and cause-specific mortality according to the urinary β₂ -MG concentrations. Risk ratios (RRs) were assessed using the Fine and Gray regression model to account for competing risks of cause-specific mortality. The mortality rate was significantly higher in participants with urinary β₂ -MG concentrations >1000 μg/g creatinine (Cr) for men and >300 μg/g Cr for women. In the proportional hazard model, higher urinary β₂ -MG concentrations were associated with higher risks of circulatory disease, digestive system diseases, and kidney and urinary tract diseases in men and women, and with senility for women. However, when competing risk was accounted for, the RRs were significantly higher only for kidney and urinary tract diseases in men and women (RR for each increment of 1000 μg/g Cr [95% confidence interval]: 1.02 [1.00-1.04] for men, and 1.01 [1.00-1.02] for women). The long-term prognosis of participants with renal tubular dysfunction was poor, most likely due to kidney and renal tract diseases.