Lead Levels in Spices From Market Basket and Home Lead Investigation Samples in North Carolina

OBJECTIVES

Lead investigators in North Carolina found evidence that contaminated spices may contribute to children's elevated blood lead levels. We compared lead levels in samples of spices and other consumable products by country of purchase to inform consumer safety interventions and regulations.

METHODS

From February 1, 2011, through October 22, 2020, North Carolina lead investigators sampled spices and other consumable products from 103 homes of children with confirmed elevated blood lead levels. In 2017, the study team purchased 50 products frequently sampled during lead investigations, as a "market basket" sample, from local stores in or near Raleigh, North Carolina. The State Laboratory of Public Health analyzed 423 product samples using mass spectrometry. We extracted environmental sample results from lead investigations from the North Carolina Electronic Lead Surveillance System.

RESULTS

The median market basket lead result was 0.07 mg/kg (SD = 0.17); the maximum lead result was 0.88 mg/kg. The median home lead investigation sample result was 0.26 mg/kg (SD = 489.44); the maximum lead result was 6504.00 mg/kg in turmeric purchased in India. Among all samples, products purchased in India had more than triple the median lead levels (0.71 mg/kg) of those purchased in the United States (0.19 mg/kg).

CONCLUSIONS

Purchasing spices in the United States is an action that consumers can take that may reduce their lead poisoning risk. Regulatory agencies should consider a lead limit of <1 mg/kg as attainable for spices sold in US stores and for ingredients of any foods that may be consumed by children.

Exploration of the effects of classroom humidity levels on teachers' respiratory symptoms

PURPOSE

Previous studies indicate that teachers have higher asthma prevalence than other non-industrial worker groups. Schools frequently have trouble maintaining indoor relative humidity (RH) within the optimum range (30-50 %) for reducing allergens and irritants. However, the potential relationship between classroom humidity and teachers' health has not been explored. Thus, we examined the relationship between classroom humidity levels and respiratory symptoms among North Carolina teachers.

METHODS

Teachers (n = 122) recorded daily symptoms, while data-logging hygrometers recorded classroom RH levels in ten North Carolina schools. We examined effects of indoor humidity on occurrence of symptoms using modified Poisson regression models for correlated binary data.

RESULTS

The risk of asthma-like symptoms among teachers with classroom RH >50 % for 5 days was 1.27 (95 % Confidence Interval (CI) 0.81, 2.00) times the risk among the referent (teachers with classroom RH 30-50 %). The risk of cold/allergy symptoms among teachers with classroom RH >50 % for 5 days was 1.06 (95 % CI 0.82, 1.37) times the risk among the referent. Low RH (<30 %) for 5 days was associated with increased risk of asthma-like [risk ratio (RR) = 1.26 (95 % CI 0.73, 2.17)] and cold/allergy symptoms [RR = 1.11 (95 % CI 0.90, 1.37)].

CONCLUSIONS

Our findings suggest that prolonged exposure to high or low classroom RH was associated with modest (but not statistically significant) increases in the risk of respiratory symptoms among teachers.

The effects of building-related factors on classroom relative humidity among North Carolina schools participating in the 'Free to Breathe, Free to Teach' study

Both high and low indoor relative humidity (RH) directly impact Indoor Air Quality (IAQ), an important school health concern. Prior school studies reported a high prevalence of mold, roaches, and water damage; however, few examined associations between modifiable classroom factors and RH, a quantitative indicator of dampness. We recorded RH longitudinally in 134 North Carolina classrooms (n = 9066 classroom-days) to quantify the relationships between modifiable classroom factors and average daily RH below, within, or above levels recommended to improve school IAQ (30-50% or 30-60% RH). The odds of having high RH (>60%) were 5.8 [95% Confidence Interval (CI): 2.9, 11.3] times higher in classrooms with annual compared to quarterly heating, ventilating, and air-conditioning (HVAC) system maintenance and 2.5 (95% CI: 1.5, 4.2) times higher in classrooms with HVAC economizers compared to those without economizers. Classrooms with direct-expansion split systems compared to chilled water systems had 2.7 (95% CI: 1.7, 4.4) times higher odds of low RH (<30%). When unoccupied, classrooms with thermostat setbacks had 3.7 (95% CI: 1.7, 8.3) times the odds of high RH (>60%) of those without setbacks. This research suggests actionable decision points for school design and maintenance to prevent high or low classroom RH.

PRACTICAL IMPLICATIONS

This study combines longitudinal measurements of classroom relative humidity with school inspection data from several schools to describe the problem of relative humidity control in schools. Our findings on how maintenance and mechanical factors affect classroom humidity provide suggestions on building operations policies and heating, ventilating, and air-conditioning (HVAC) design considerations that may improve classroom relative humidity control.

Inequalities in the nuclear age: impact of race and gender on radiation exposure at the Savannah River Site (1951-1999)

Changes in the workforce during the civil rights movement may have impacted occupational exposures in the United States. We examined Savannah River Site (SRS) employee records (1951-1999) for changes in radiation doses and monitoring practices, by race and sex. Segregation of jobs by race and sex diminished but remained pronounced in recent years. Female workers were less likely than males to be monitored for occupational radiation exposure [odds of being unmonitored = 3.11; 95% CI: (2.79, 3.47)] even after controlling for job and decade of employment. Black workers were more likely than non-black workers to have a detectable radiation dose [OR = 1.36 (95% CI: 1.28, 1.43)]. Female workers have incomplete dose histories that would hinder compensation for illnesses related to occupational exposures. The persistence of job segregation and excess radiation exposures of black workers shows the need for further action to address disparities in occupational opportunities and hazardous exposures in the U. S. South.