Cadmium exposure in the population: from health risks to strategies of prevention

We focus on the recent evidence that elucidates our understanding about the effects of cadmium (Cd) on human health and their prevention. Recently, there has been substantial progress in the exploration of the shape of the Cd concentration-response function on osteoporosis and mortality. Environmental exposure to Cd increases total mortality in a continuous fashion without evidence of a threshold, independently of kidney function and other classical factors associated with mortality including age, gender, smoking and social economic status. Pooled hazard rates of two recent environmental population based cohort studies revealed that for each doubling of urinary Cd concentration, the relative risk for mortality increases with 17% (95% CI 4.2–33.1%; P < 0.0001). Tubular kidney damage starts at urinary Cd concentrations ranging between 0.5 and 2 μg urinary Cd/g creatinine, and recent studies focusing on bone effects show increased risk of osteoporosis even at urinary Cd below 1 μg Cd/g creatinine. The non-smoking adult population has urinary Cd concentrations close to or higher than 0.5 μg Cd/g creatinine. To diminish the transfer of Cd from soil to plants for human consumption, the bioavailability of soil Cd for the plants should be reduced (external bioavailability) by maintaining agricultural and garden soils pH close to neutral (pH-H₂O of 7.5; pH-KCL of 6.5). Reducing the systemic bioavailability of intestinal Cd can be best achieved by preserving a balanced iron status. The latter might especially be relevant in groups with a lower intake of iron, such as vegetarians, and women in reproductive phase of life. In exposed populations, house dust loaded with Cd is an additional relevant exposure route. In view of the insidious etiology of health effects associated with low dose exposure to Cd and the current European Cd intake which is close to the tolerable weekly intake, one should not underestimate the importance of the recent epidemiological evidence on Cd toxicity as to its medical and public health implications.     

Effectiveness of health checks conducted by nurses in primary care: final results of the OXCHECK study. Imperial Cancer Research Fund OXCHECK Study Group.

OBJECTIVE--To determine the effectiveness of health checks, performed by nurses in primary care, in reducing risk factors for cardiovascular disease and cancer. DESIGN--Randomised controlled trial. SETTING--Five urban general practices in Bedfordshire. SUBJECTS--2205 men and women who were randomly allocated a first health check in 1989-90 and a re-examination in 1992-3 (the intervention group); 1916 men and women who were randomly allocated an initial health check in 1992-3 (the control group). All subjects were aged 35-64 at recruitment in 1989. MAIN OUTCOME MEASURES--Serum total cholesterol concentration, blood pressure, body mass index, and smoking prevalence (with biochemical validation of cessation); self reported dietary, exercise, and alcohol habits. RESULTS--Mean serum total cholesterol was 3.1% lower in the intervention group than controls (difference 0.19 mmol/l (95% confidence interval 0.12 to 0.26)); in women it was 4.5% lower (P < 0.0001) and in men 1.6% (P < 0.05), a significant difference between the sexes (P < 0.01). Self reported saturated fat intake was also significantly lower in the intervention group. Systolic and diastolic blood pressures and body mass index were respectively 1.9%, 1.9%, and 1.4% lower in the intervention group (P < 0.005 in all cases). There was a 3.9% (2.4 to 5.3) difference in the percentage of subjects with a cholesterol concentration > or = 8 mmol/l, but no significant differences in the number with diastolic blood pressure > or = 100 mm Hg or body mass index > or = 30 kg/m2. There was no significant difference between the two groups in prevalence of smoking or excessive alcohol use. Annual rechecks were no more effective than a single recheck at three years, but health checks led to a significant increase in visits to the nurse according to patients'' degree of cardiovascular risk. CONCLUSIONS--The benefits of health checks were sustained over three years. The main effects were to promote dietary change and reduce cholesterol concentrations; small differences in blood pressure may have been attributable to accommodation to measurement. The benefits of systematic health promotion in primary care are real, but must be weighed against the costs in relation to other priorities.     

Anthropometric, body composition and health determinants of active ageing: a gender approach

This study applied a gender perspective to establish some of the anthropometric, body composition, health and socio-cultural determinants of active ageing. The variable 'active ageing' (presence/absence) was created based on cognitive and disability/illness/physical functioning, subjective health, satisfaction with life and productive activity performed, and used in predictive models to establish its relationship with anthropometric variables, physical health indicators and educational level. The sample consisted of 456 home-living individuals (169 men and 287 women; age range 54-75 years) from Madrid and Toledo in Spain. The women had a higher prevalence of obesity than the men (37.6% vs 29.0%), significantly greater fat accumulation in the abdominal area and worst perceived health (p=0.003). The frequency of active agers is higher in men than in women (38.4% vs 21.9%; p<0.001). Men and women were found to have distinctive ageing patterns. Health factors condition the presence of active ageing in women, while education factors are also relevant in men.     

Groundwater contamination with cadmium concentrations in some West U.P. Regions,India

Water is considered a vital resource because it is necessary for all aspects of human and ecosystem survival. However, due to natural processes and anthropogenic activities, various pollutants have been added to the ground water system. Among these, heavy metals are some of the most serious pollutants. Cd, a toxic heavy metal used in Ni-Cd batteries, the colouration of plastic and various discarded electronic products released into the water system causes serious health issues. The chronic exposure to Cd produces a wide variety of acute and chronic effects in humans. Cd accumulates in the human body, especially in the kidneys, resulting in kidney damage (renal tubular damage), which is a critical health effect. Other effects of Cd exposure are disturbances in calcium metabolism, hypercalciuria and the formation of kidney stones. High exposure to Cd can lead to lung cancer and prostate cancer; hence, poor quality water that may result in Cd toxicity has become a global concern. Thus, the aim of this study is to determine the concentration of Cd in underground water sources in western U.P. regions. Water samples were acidified to 1% with nitric acid and then stored in double-capped polyethylene bottles for further analysis by an atomic absorption spectrophotometer. After comparing the data to the WHO (2011) permissible limit, the study revealed that the concentration of Cd was higher than the regulatory threshold; therefore, the underground water system is seriously affected by Cd toxicity.     

Environmental exposure and preventive measures in Sweden and EU*

Environmental exposure to cadmium (Cd) gives rise to renal tubular dysfunction at low cumulative doses of Cd. A possible role of Cd in influencing the occurrence of diseases, e.g., bone, reproductive and cancer in the general population groups environmentally exposed to Cd has been reported from Japan, Belgium, Sweden and China. Authorities have to pay attention to this fact and to act in order to prevent serious outcomes and personal suffering in the population groups at risk. A general approach in setting recommended health based limits and to regulate the occurrence of a substance existing in food stuff is to keep low levels -better to be on the safer side than on the risk side. In the case of cadmium it should be most clear that since cadmium has a very long biological half-life of 20 years in humans, increased cadmium exposure due to human activities can never be accepted. In cases where cadmium exposure can not be avoided the approach should be to limit and decrease exposure. Presently FAO/WHO Expert Committee on Food Additives and Food has a PTWI (provisional tolerable weekly intake) value for adult persons of 7 microg/kg body weight for Cd (WHO 2003) a value corresponding to 1 microg/kg body weight for each day of a week. For children and pregnant or lactating women daily intakes should not exceed 1 microg/kg body weight.     

Education,Health Behaviors,and the Black-White Difference in Waist-to-Hip Ratio

Few epidemiologic studies have investigated the impact of body mass index, low educational attainment, cigarette smoking, and physical activity on the considerable black-white difference in waist-to-hip ratio. These relationships were assessed with multi-variable linear regression among 3,094 adults (24% black) who were examined in 1987 in South Carolina. The unadjusted mean waist-to-hip ratio was lower for black men than for white men (-0.03 units) and higher for black women than for white women (+0.03 units). After adjustment for age, body mass index, education, smoking, and physical activity, the black-white difference in mean waist-to-hip ratio was ?0.02 units (p<0.001) among men and +0.01 units (p<0.01) among women. Although differing distributions of age, body mass index, and educational attainment accounted for a 59% reduction in the black-white difference among women, these factors did not explain the difference among men. Thus, these results suggest that other environmental or biologic factors may also play an important role in the marked variation in body fat distribution between the two ethnic groups. The results also support the importance of the prevention of cigarette smoking and overweight in potentially preventing abdominal obesity in both black adults and white adults.     

Maternal urinary cadmium concentrations in early pregnancy in relation to prenatal and postpartum size of offspring

BackgroundThe impacts of environmental cadmium (Cd) exposure on birth size parameters including weight, length and head circumference (HC) have been reported in multiple studies. However, little remains known of the impacts of maternal Cd exposure during pregnancy on size during in utero development and during early childhood. The aim of this study was to comprehensively investigate impacts of maternal Cd exposure during pregnancy on the size of offspring in utero (from 24 weeks pregnancy) until six months of age.MethodsPregnant mothers were recruited as part of an ongoing prospective birth cohort study based in Guangdong, China. Maternal urine samples were collected in the first and third trimesters of pregnancy, in which Cd concentrations were measured by inductively couple plasma mass spectrometry (ICPMS). In utero size indicators at 24 and 32 week of gestation, including biparietal diameter (BPD), abdominal circumference (AC), femur length (FL) and HC were derived from ultrasound examinations. Anthropometric measures of weight, height and HC at birth and one, three and six months of age were also collected. Associations of size measures at the various time points with maternal urinary Cd concentrations were assessed using linear regression models.ResultsThe median urinary Cd concentration was 1.00 and 0.98 μg/g creatinine in the first and third trimesters respectively. In univariate analysis, increased maternal Cd levels in the first trimester were associated with decreased HC (-0.17 cm/ug/g urinary Cd) at birth, and the association was particularly pronounced among males (-0.30 cm/ug/g urinary Cd). First trimester Cd exposure was also found to be significantly associated with decreased infant weight at three and six months of age among girls (−101 g/ug/g and −97 g/ug/g urinary Cd, respectively). Associations of similar magnitude were observed after adjustment for various maternal factors. No significant associations were observed with infant size measures or with measures of Cd in the third trimester.ConclusionsOur detailed study suggests that the first trimester is particularly critical window of susceptibility to sex-specific effects of Cd on size parameters at birth, with some effects persisting to six months of age. These compelling sex-dependent effects on HC and body weight warrant future studies examining longer-term health effects of pregnancy-related Cd exposures.     

Gender differences in predictors of body weight and body weight change in healthy adults

Background: Overweight and obesity are important predictors of a wide variety of health problems. Analysis of naturally occurring changes in body weight can provide valuable insights in improving our understanding of the influence of demographic, lifestyle, and psychosocial factors on weight gain in middle‐age adults. Objective: To identify gender‐specific predictors of body weight using cross‐sectional and longitudinal analyses. Methods and Procedures: Anthropometric, lifestyle and psychosocial factors were measured at baseline and then quarterly for 1 year in 572 healthy adult volunteers from Central Massachusetts who were recruited between 1994 and 1998. Linear mixed models were used to analyze the relationship between body weight and potential predictors, including demographic (e.g., age, educational level), lifestyle (e.g., diet, physical activity, smoking), and psychosocial (e.g., anxiety, depression) factors. Results: Over the 1‐year study period, on average, men gained 0.3 kg and women lost 0.2 kg. Predictors of lower body weight at baseline in both men and women included current cigarette smoking, greater leisure‐time physical activity, and lower depression and anxiety scores. Lower body weights were associated with a lower percentage of caloric intake from protein and greater occupational physical activity levels only among men; and with higher education level only among women. Longitudinal predictors of 1‐year weight gain among women included increased total caloric intake and decreased leisure‐time physical activity, and among men, greater anxiety scores. Discussion: Demographic, lifestyle and psychosocial factors are independently related to naturally occurring changes in body weight and have marked differential gender effects. These effects should be taken into consideration when designing interventions for weight‐loss and maintenance at the individual and population levels.     

女性体检人群生殖道病原体的分布

目的了解体检妇女人群生殖道感染情况,为女性生殖道感染的防治提供进一步的资料。方法对1157例参加健康体检的妇女的阴道后穹窿及宫颈分泌物标本进行显微镜镜检以检测阴道清洁度、真菌、滴虫等,同时采用培养法对淋球菌、解脲支原体、人型支原体、真菌等进行检测,沙眼衣原体则采用免疫层析法;检测结果进行统计学分析。结果女性生殖道感染的感染率为54.0%,其中混合感染率为9.3%,而清洁度异常率仅为23.8%;前3位病原体依次为解脲支原体(35.3%)、衣原体(22.2%)、真菌(5.5%);年轻妇女组与年老组支原体的检出率差异有显著性(P<0.05)。结论女性生殖道感染情况严重,支原体、衣原体等感染隐匿,加强对育龄妇女的监测尤为重要。     

Effectiveness of health checks conducted by nurses in primary care: results of the OXCHECK study after one year. Imperial Cancer Research Fund OXCHECK Study Group.

OBJECTIVE--To assess the effectiveness of health checks by nurses in reducing risk factors for cardiovascular disease in patients from general practice. DESIGN--Randomised controlled trial. SETTING--Five urban general practices in Bedfordshire. SUBJECTS--2136 patients receiving an initial health check in 1989-91 and scheduled to be re-examined one year later in 1990-2 (intervention group); 3988 patients receiving an initial health check in 1990-2 (control group). All patients were aged 35-64 years at recruitment in 1989. MAIN OUTCOME MEASURES--Serum total cholesterol concentration, blood pressure, body mass index, confirmed smoking cessation. RESULTS--Mean serum total cholesterol was 2.3% lower in the intervention group than in the controls (difference 0.14 mmol/l (95% confidence interval 0.08 to 0.20)); the difference was greater in women (3.2%, P < 0.0001) than men (1.0%, P = 0.18). There was no significant difference in smoking prevalence, quit rates, or body mass index. Systolic and diastolic blood pressure were 2.5% and 2.4% lower respectively in the intervention group. The proportion of patients with diastolic blood pressure > or = 100 mm Hg was 2.6% (55/2131) in the intervention group and 3.4% (137/3987) in the controls (difference 0.9% (0.0 to 1.7)); the proportion with total cholesterol concentration > or = 8 mmol/l 4.8% (100/2068) and 7.6% (295/3905) (difference 2.7% (1.5 to 4.0)); and that with body mass index > or = 30 12.4% (264/2125) and 14.0% (559/3984) (difference 1.6% (-0.2 to 3.4)). CONCLUSIONS--General health checks by nurses are ineffective in helping smokers to stop smoking, but they help patients to modify their diet and total cholesterol concentration. The public health importance of this dietary change depends on whether it is sustained.     

Cadmium Mimics Estrogen-Driven Cell Proliferation and Prolactin Secretion from Anterior Pituitary Cells

Cadmium (Cd) is a heavy metal of considerable occupational and environmental concern affecting wildlife and human health. Recent studies indicate that Cd, like other heavy metals, can mimic effects of 17β-estradiol (E2) involving E2 receptor (ER) activation. Lactotrophs, the most abundant cell type in anterior pituitary gland, are the main target of E2, which stimulates cell proliferation and increases prolactin secretion through ERα. The aim of this work was to examine whether Cd at nanomolar concentrations can induce cell proliferation and prolactin release in anterior pituitary cells in culture and whether these effects are mediated through ERs. Here we show that 10 nM Cd was able to stimulate lactotroph proliferation in anterior pituitary cell cultures from female Wistar rats and also in GH3 lactosomatotroph cell line. Proliferation of somatotrophs and gonadotrophs were not affected by Cd exposure. Cd promoted cell cycle progression by increasing cyclins D1, D3 and c-fos expression. Cd enhanced prolactin synthesis and secretion. Cd E2-like effects were blocked by the pure ERs antagonist ICI 182,780 supporting that Cd acts through ERs. Further, both Cd and E2 augmented full-length ERαexpression and its 46 kDa-splicing variant. In addition, when co-incubated Cd was shown to interact with E2 by inducing ERα mRNA expression which indicates an additive effect between them. This study shows for the first time that Cd at nanomolar concentration displays xenoestrogenic activities by inducing cell growth and stimulating prolactin secretion from anterior pituitary cells in an ERs-dependent manner. Cd acting as a potent xenoestrogen can play a key role in the aetiology of different pathologies of the anterior pituitary and in estrogen-responsive tissues which represent considerable risk to human health.     

Toxicological interaction between tobacco smoke toxicants cadmium and nicotine: An in-vitro investigation

Cigarettes and other tobacco products are used to obtain nicotine that is responsible for their stimulating effects. However, a lot of other organic and inorganic chemicals are also released along with nicotine. Cadmium (Cd) is one of the several heavy metals that are health hazards and is one of the inorganic elements released in tobacco smoke. The in-vitro investigation focused on exploring the effects of nicotine hydrogen tartrate (NHT) and cadmium (Cd) and their toxic interactions in the A549 cell line. In cell viability assay NHT exhibited its IC₅₀ at 11.71 mM concentration, and the IC₅₀ of Cd was found to be 83 µM after a 24 h exposure. Toxic effects of NHT (5 mM and 10 mM), Cd (50 µM and 100 µM), and their combination were also investigated by flowcytometry. The investigation included apoptotic and necrotic events, the effect on different cell cycle phases, and generation of reactive oxygen species by NHT, Cd, and their combination of different concentrations. Data reveal evident toxic effects of NHT, Cd, and NHT + Cd. It also indicates that the toxic interaction of NHT and Cd is not additive and appears to be minimal when compared with NHT or Cd exposures alone.     

Can Body Condition and Somatic Indices be Used to Evaluate Metal-Induced Stress in Wild Small Mammals?

Wildlife is exposed to natural (e.g., food availability and quality, parasitism) and anthropogenic stressors (e.g., habitat fragmentation, toxicants). Individual variables (e.g., age, gender) affect behaviour and physiology of animals. Together, these parameters can create both great inter-individual variations in health indicators and interpretation difficulties. We investigated the relevance of body condition and somatic indices (liver, kidneys) as indicators of health status in wood mice (Apodemus sylvaticus, n = 560) captured along a metal pollution gradient in four landscape types (30 sampling squares 500-m sided). The indices were calculated using a recently proposed standard major axis regression instead of an ordinary least square regression. After considering age and gender for the body condition index, no landscape type influence was detected in the indices. However, important index variability was observed between sampling squares; this effect was included as a random effect in linear models. After integrating all individual and environmental variables that may affect the indices, cadmium (Cd) concentrations in both the liver and kidneys were negatively related to body condition and liver indices only for individuals from highly contaminated sites. Lead in the liver was negatively related to the liver index, and Cd in kidneys was positively linked to the kidney index, potentially suggesting metal-induced stress. However, interpretation of these indices as a wildlife ecotoxicology tool should be performed with caution due to the sensitivity of potentially confounding variables (e.g., individual factors and environmental parameters).     

Low cadmium (LCD), a novel gene related to cadmium tolerance and accumulation in rice

The contamination of food crops by cadmium (Cd) is a major concern in food production because it can reduce crop yields and threaten human health. In this study, knockout rice plants (Oryza sativa) tagged with the gene trap vector pGA2707 were screened for Cd tolerance, and the tolerant line lcd was obtained. The lcd mutant showed tolerance to Cd on agar plates and in hydroponic culture during early plant development. Metal concentration measurements in hydroponically grown plants revealed significantly less Cd in the shoots of lcd plants compared with wild-type (WT) shoots. When cultured in the field in soil artificially contaminated with low levels of Cd, lcd showed no significant difference in the Cd content of its leaf blades; however, the Cd concentration in the grains was 55% lower in 2009 and 43% lower in 2010. There were no significant differences in plant dry weight or seed yield between lcd and wild-type plants. LCD, a novel gene, is not homologous to any other known gene. LCD localized to the cytoplasm and nucleus, and was expressed mainly in the vascular tissues in the roots and phloem companion cells in the leaves. These data indicate that lcd may be useful for understanding Cd transport mechanisms and is a promising candidate rice line for use in combating the threat of Cd to human health.     

Accumulation of Cd and Pb in various body parts,organs and tissues of Lymantria dispar asiatica (Lepidoptera: Erebidae)

To investigate the accumulation patterns of Cd and/or Pb in various body parts, organs and tissues of the Asian gypsy moth (Lymantria dispar) larvae under Cd and/or Pb stress, Cd and Pb treated artificial diets were used to feed the larvae in the current study. These larval body parts/organs/tissues included the heads, integuments (body walls), alimentary canals, fat bodies and hemolymphs. Our results showed that under Cd and/or Pb stress, their accumulations in larval body parts/organs/tissues were significantly higher than those in the control, with the amounts of tested metals in the fat bodies and hemolymphs and alimentary canals being significantly higher than those in the heads and integuments. Under the single Cd (0, 7.5, 10.5 mg/kg) or Pb stress (0, 55, 90, 125 mg/kg), the accumulations of these heavy metals were positively correlated with their concentrations in diets. Under the combined stress (Cd × Pb), the Cd accumulation at the lower Pb concentrations was higher than that at higher Pb concentrations for the body parts/organs/tissues, similar effects of Cd concentrations on Pb accumulations were also recorded. These results clearly showed that Cd and/or Pb were accumulated in various body parts/organs/tissues at different levels under the heavy metal stress. And accumulations of Pb/Cd were positively correlated with their concentrations in the diets under the single stress. Under the combined stresses, Cd and Pb had synergistic effects at low concentrations whereas antagonistic effects at high concentrations. The accumulations of Cd and/or Pb in the gypsy moth larvae affects normal physiological and biochemical functions, and thus affects their growth and development.     

Racial Disparities in the Association between Alcohol Use Disorders and Health in Black and White Women

Adverse health attributed to alcohol use disorders (AUD) is more pronounced among black than white women. We investigated whether socioeconomic status (education and income), health care factors (insurance, alcoholism treatment), or psychosocial stressors (stressful life events, racial discrimination, alcoholism stigma) could account for black-white differences in the association between AUD and physical and functional health among current women drinkers 25 years and older (N = 8,877) in the National Epidemiological Survey on Alcohol and Related Conditions. Generalized linear regression tested how race interacted with the association between 12-month DSM-IV AUD in Wave 1 (2001–2002) and health in Wave 2 (2004–2005), adjusted for covariates (age group, alcohol consumption, smoking, body mass index, physical activity, diabetes, cardiovascular disease, and arthritis). Black women with AUD had poorer health than white women with AUD (β = ?3.18, SE = 1.28, p < .05). This association was partially attenuated after adjusting for socioeconomic status, health care, and psychosocial factors (β = ?2.64, SE = 1.27, p < .05). In race-specific analyses, AUD was associated with poorer health for black but not white women. Accounting for black-white differences in AUD and physical and functional health among women requires investigation beyond traditional explanatory mechanisms.     

Sex differences in obesity rates in poor countries: Evidence from South Africa

Globally, men and women face markedly different risks of obesity. In all but of handful of (primarily Western European) countries, obesity is much more prevalent among women than men. We examine several potential explanations for this phenomenon. We analyze differences between men and women in reports and effects of potential underlying causes of obesity—childhood and adult poverty, depression, and attitudes about obesity. We evaluate the evidence for each explanation using data collected in an urban African township in the Cape Town metropolitan area. Three factors explain the greater obesity rates we find among women. Women who were nutritionally deprived as children are significantly more likely to be obese as adults, while men who were deprived as children face no greater risk. In addition, women of higher adult socioeconomic status are significantly more likely to be obese, which is not true for men. These two factors - childhood circumstances and adult SES - can fully explain the difference in obesity rates between men and women that we find in our sample. More speculatively, in South Africa, women's perceptions of an ‘ideal’ female body are larger than men's perceptions of the ‘ideal’ male body, and individuals with larger ‘ideal’ body images are significantly more likely to be obese.     

Combined impact of health behaviours and mortality in men and women: the EPIC-Norfolk prospective population study

Background

There is overwhelming evidence that behavioural factors influence health, but their combined impact on the general population is less well documented. We aimed to quantify the potential combined impact of four health behaviours on mortality in men and women living in the general community.

Methods and Findings

We examined the prospective relationship between lifestyle and mortality in a prospective population study of 20,244 men and women aged 45–79 y with no known cardiovascular disease or cancer at baseline survey in 1993–1997, living in the general community in the United Kingdom, and followed up to 2006. Participants scored one point for each health behaviour: current non-smoking, not physically inactive, moderate alcohol intake (1–14 units a week) and plasma vitamin C >50 mmol/l indicating fruit and vegetable intake of at least five servings a day, for a total score ranging from zero to four. After an average 11 y follow-up, the age-, sex-, body mass–, and social class–adjusted relative risks (95% confidence intervals) for all-cause mortality(1,987 deaths) for men and women who had three, two, one, and zero compared to four health behaviours were respectively, 1.39 (1.21–1.60), 1.95 (1.70–-2.25), 2.52 (2.13–3.00), and 4.04 (2.95–5.54) p < 0.001 trend. The relationships were consistent in subgroups stratified by sex, age, body mass index, and social class, and after excluding deaths within 2 y. The trends were strongest for cardiovascular causes. The mortality risk for those with four compared to zero health behaviours was equivalent to being 14 y younger in chronological age.

Conclusions

Four health behaviours combined predict a 4-fold difference in total mortality in men and women, with an estimated impact equivalent to 14 y in chronological age.     

Effects of Cd or/and Pb on soil enzyme activities and microbial community structure

Heavy metals could have long-term hazardous impacts on the health of soil ecosystems and adverse influences on soil biological processes. A study of Cd or/and Pb effects on soil enzyme activities and microbial community structure was undertaken with brown soil in a greenhouse for a period of 10 weeks. The experiment results showed that urease, acid phosphatase and dehydrogenase activities were significantly lower (p < 0.05) in Cd or/and Pb treatments than in control. Three enzyme activities decreased with the increasing metal concentrations. The effects of Cd and Pb combined on enzyme activities were higher than Cd or Pb alone. The soil microbial populations were far lower in heavy metal treatments than in control, and soil microbial populations under different heavy metals levels showed a significant difference (p < 0.05). The PCR-DGGE banding patterns confirmed that the addition of metals had a significant impact on microbial community structure.     

Health perceptions and demographic characteristics associated with underassessment of body weight

Objectives: To describe the relationship between BMI and perceived weight status and to determine how underassessment of weight status is associated with demographic characteristics, self‐reported general health, and perceived health risk in relation to one's body weight. Methods and Procedures: In the 2004 Styles surveys, 3,888 US adult participants described their current weight status (underweight, about right, slightly overweight, very overweight), which we compared with self‐reported BMI in order to determine concordance. We used multivariable logistic regression to evaluate associations between underassessment of body weight and characteristics of interest. Results: Among persons with a BMI ≥25, women were more likely than men to recognize their overweight status (slightly or very overweight; 93.0% of women vs. 73.5% of men) and the extent to which they were overweight: 70.4% of obese women vs. 49.5% of obese men described themselves as very overweight. Among the overweight and obese of both sexes, disagreement with regard to current weight as a health risk was associated with underassessment of weight. Additional factors associated with underassessment were education and race/ethnicity among overweight women; race/ethnicity among overweight men; household income and self‐rated health among obese women; and self‐rated health among obese men (P < 0.05). Discussion: While most of the obese participants recognized that they were overweight, many of them, particularly among the men, did not realize the extent to which they were overweight. Public health messages may be more effective if they are specifically tailored to target audiences, besides emphasizing the health risks associated with excess body weight.