Negative emotionality, activity, and sociability temperaments predicting long-term job strain and effort-reward imbalance: a 15-year prospective follow-up study.

OBJECTIVE: This study examined a longitudinal association between innate temperament and perceptions of long-term work stressors. METHODS: The sample consisted of 276 men and 345 women (aged 30-45 years in 2007) participating in the prospective population-based Cardiovascular Risk in Young Finns study. In 1992, temperament was self-assessed with the EAS questionnaire that assesses three temperamental traits: negative emotionality, activity, and sociability. Perceived work stressors were measured in 2001 and in 2007 using two models: Karasek's demand/control-model in which a combination of high demands and low control results in job strain, and Siegrist's Effort-reward imbalance (ERI) model. RESULTS: The results showed that higher negative emotionality and lower sociability systematically predicted higher perceived job strain and ERI (P<.001). Activity predicted higher perceived ERI (P<.05). Activity did not predict perceived job strain, as it was related to both higher perceived demands and higher control. CONCLUSIONS: The results suggest that temperament may be a predisposing factor to the experiences of work stressors in adulthood. Although self-reported job strain and ERI are measures of job characteristics, they are affected by individual temperament.

Cadmium in food chain and health effects in sensitive population groups.

Even at the low exposure level of cadmium found in this study population living on farms in southern Sweden, there was an indication of effect on biochemical markers of renal function. Women had higher blood cadmium (BCd) and urinary cadmium (UCd) than men, which can be explained by higher absorption of Cd due to low iron status. In the present study, Cd in pig kidneys could not be used to predict human BCd or UCd even though cereals are a substantial part of both the human and the pig diet. The contribution of Cd from locally produced food to the total dietary intake in humans was relatively low and varied and the intake of Cd did not correlate with BCd or UCd. In contrast, Cd levels in pig kidney were significantly related to Cd levels in feed. However, there was no relationship between the locally produced cereals, constituting the main part of the feed, and Cd in pig kidneys. In pig feed, other non-locally produced ingredients contributed to a large part of the Cd in feed. The Cd in non-locally produced feed ingredients reaches the local circulation via excretion in faeces and application of manure to arable soils and will lead to increased levels in the crops. As indicated by experimental data from animals, neurochemical and neurobehavioral effects during development need to be further explored as sensitive endpoints for cadmium toxicity.