Spice Lead Levels and Blood Lead Levels in Maryland Children

Kyle Shannon

Rapid Response Team Coordinator

Maryland Department of Health and Mental Hygiene

International Food Protection Training Institute (IFPTI)

2017 Fellow in Applied Science, Law, and Policy: Fellowship in Food Protection

Author Note

Kyle Shannon, Rapid Response Team Coordinator, Maryland Department of Health and Mental Hygiene.

This research was conducted as part of the International Food Protection Training Institute’s Fellowship in Food Protection, Cohort VI.

Correspondence concerning this article should be addressed to Kyle Shannon, Maryland Department of Health and Mental Hygiene, 6 St. Paul Street, Suite 1301, Baltimore, MD 21202-1614; Email: kyle.shannon@maryland.gov

Abstract

This retrospective study examines the relationship between spice lead levels and blood lead levels in Maryland children based on case investigations conducted by the Maryland Department of the Environment (MDE) from January 1, 2013, through December 31, 2016. These cases were reviewed to determine the environmental antecedents associated with the elevated blood lead levels (EBLL). In 52 of 534 cases, spices were identified as an environmental antecedent. In the 42 cases in which spice samples were collected, 47% had detectable levels of lead. The study also found lead levels above the Food and Drug Administration’s (FDA) guidance level for lead in candy in over 62% of spice samples collected by the Maryland Department of Health and Mental Hygiene (MDHMH) between January 7, 2014, and May 5, 2016, and in over 71% collected by the New York State Department of Agriculture and Markets (NYSDAM) between February 15, 2011, and August 15, 2016. The study recommends: (1) evaluating and recording the consumption levels of spices if there is a suspect lead risk found during a childhood lead investigation; (2) creating a national regulatory or guidance level for lead in spices; (3) increasing educational outreach regarding “non-tradition sources” of lead exposure; (4) that Laboratories conducting analytical testing of lead in food use a method appropriate for solid matrices with a low “limit of detection” (LOD) and; (5) conducting a follow-on study to identify a baseline and further evaluate whether spices present a lead hazard.

Background

Lead is a naturally occurring element found in all parts of the environment such as in the air, soil, and water. Additional lead can enter the environment due to the release of lead by human activities such as past use of leaded gasoline and lead based paint; lead and lead compounds also have been used in household products such as ceramics, plumbing pipes and materials, batteries, ammunition, and cosmetics. The most common sources of exposure among children with blood lead levels above the Centers for Disease Control and Prevention (CDC) reference value of 5 ug/dL of blood are lead hazards in and around older housing, including deteriorated lead-based paint, lead-contaminated dust, and accessible lead contaminated soil (CDC, 2012). The main target for lead toxicity is the nervous system, both in adults and children. At high levels of exposure, lead can severely damage the brain and kidneys in adults or children and ultimately cause death. In pregnant women, high levels of exposure to lead may cause miscarriage. (Department of Health & Human Services [DHHS], 2007). Chronic exposure, particularly in children is associated with impaired cognitive function (CDC, 2012).

Dietary exposure to lead has received less attention than the traditional environmental antecedents such as deteriorated lead-based paint and lead contaminated dust. Only two federal regulatory limits for lead exist at present. The Environmental Protection Agency (EPA) has a limit of 0.015 ppm in drinking water (National Primary Drinking Water Regulations, 2010) and the FDA has a guidance level of 0.1 ppm in candy. (FDA, 2006). Contamination of food animals and crops does occur due to contaminated soil, heavy pesticide use, and industrial processes near food production areas.

Although there are few regulatory limits for lead in products, the FDA has set a Provisional Tolerable Total Intake Level (PTTIL) of 6 micrograms of lead per day for children 6 years of age and under. (FDA, 2006). The PTTIL is the total daily intake from all sources that provides a reasonable margin of protection against the known adverse effects of lead. When considering the PTTIL, other sources of lead must be considered as well.

However, there is still currently no recognized safe level of lead in products (CDC, 2007) nor is there a safe level of lead found in the blood (CDC, 2007). The CDC has set a “level of concern” for lead in blood of children under 6 years of age at 10ug/dL. In 2012, CDC recommended lowering this level to a “reference level” of 5 ug/dL. (CDC, 2012). The elimination of elevated blood lead levels (EBLL) (level of 10 ug/dL) in children age 6 and under also continues to be a national goal of the Healthy People 2020 initiative.

The Maryland Department of the Environment (MDE) carries out environmental investigations associated with cases where children are found to have EBLL, i.e. exceeding the CDC “level of concern.” Recent MDE investigation results suggested that EBLL in some cases may be associated with the consumption of certain spices. These investigations included a review of environmental antecedents such as household conditions including lead paint, spice, and other foods. As a result, in November 2013, MDE initiated a collaborative partnership with the Maryland Department of Health and Mental Hygiene (MDHMH) to conduct surveillance on lead levels found in spices purchased in Maryland retail facilities. This research project was designed to examine the strength of the relationship between elevated blood lead levels and consumption of certain spices by Maryland children as well as other potential sources of lead exposure.

Problem Statement

The relationship between childhood EBLL and consumption of spices in Maryland is unknown.

Research Questions

1.     What are the common lead contaminants found during Maryland Department of the Environment (MDE) lead Investigations?

2.     What are the lead levels found in certain spices consumed by children in Maryland?

3.     What is the relationship between dietary intake of certain spices by Maryland children and elevated blood lead levels?

Methodology

Data was collected during a review of MDE case investigations from January 1, 2013, through December 31, 2016. Because some data within the files were considered to be protected health information, the study methodology and data collection and analysis plan were required to be reviewed and approved by the MDHMH Institutional Review Board. Specific data of interest in the review were environmental antecedents that were discovered during the investigation, including traditional antecedents such as lead paint exposure and non-traditional exposures, particularly spices. Cases of interest were those in which MDE identified spices as a hazard, particularly those in which spices recovered from the home were tested and found to have detectable limits of lead and those in which no other antecedents were found during the investigation. For the cases in which MDE listed lead as a hazard, the files were reviewed in detail to examine whether cultural and dietary practices increased the likelihood of exposure; gather data regarding environmental sampling results particularly spices; and identify the blood lead concentrations of the children associated with these investigations. Data was also collected from spice surveillance activities performed by MDHMH between January 7, 2014, and May 5, 2016, and by New York State Department of Agriculture & Markets (NYSDAM) between February 15, 2011, and August 15, 2016, in order to examine the potential for lead in spice risks more broadly.

Four different methods were reported for the analysis based on the analytical laboratory, the reported methods were: EPA Method 6020, EPA Method 200.8, FDA Elemental Analysis Manual (EAM) Method 4.7 and NYSDAM Food Laboratory Division Method CHEM-MTH-428. The limit of detection (LOD) was reported for each spice analysis for the MDE samples using EPA Method 6020. (EPA, 2014). To allow statistical analysis of all the MDE data available, values that were reported as non-detects or below the limit of detection were reported as half the LOD. A limit of detection was provided for all MDHMH spice analysis using EPA Method 200.8 (EPA 2012) and FDA EAM Method 4.7 (FDA, 2015). A single LOD was reported for the NYSDAM Method. (NYSDAM, 2016). Values reported as less than the LOD were assigned a numeric value of half the LOD for statistical purposes. Mean lead levels were calculated for each of the sample sources. The interquartile range (IQR) was calculated to determine outliers.

Results

From January 1, 2013, through December 31, 2016, MDE conducted 534 Lead Poisoned Child Investigations. Spices were considered possible contributing factors in 52 (9.7%) of those cases by MDE investigators. In seven (1.3%) of the 534 cases only spices were found to be an antecedent during the MDE investigation after ruling out other potential sources such as lead based paint, household dust and other environmental sources.

Table 1 provides an overall summary of results by sample source. For all sample sources, the range, mean lead levels, IQR, and number of outliers were determined. The mean lead levels for all sample sources were above the FDA guidance level for lead in candy. Although the outliers were omitted in determining the mean, it is important to note the number of outliers since the lead levels in a number of the outliers were significant.

The study found that the laboratories conducting the analysis are using different methods to detect lead, which made comparing results from the various sources problematic. Reporting values depends on the method and specificity of the individual analysis. Although many samples in this study were reported as non-detects, the non-detects were assigned values of one-half of the LOD to allow statistical analysis of the data. When assigning replacement values for all “non-detects” and samples less than the LOD, all MDE data exceeded the 0.1ppm FDA guidance level. Of the MDHMH and NYSDAM values, 62%, and 71% exceeded 0.1ppm, respectively.

There appears to be a cultural component to this potential link of EBLL and spices. Of the 52 cases where MDE found spices as a potential antecedent, 39 identified a Country of Origin (CoO) of the child. Twelve different CoO were identified. Although the dataset was small, India was identified as the CoO in 14 cases which was 35.9% of the cases in which the CoO was identified. Seven cases had Pakistan identified as the CoO and five cases had Afghanistan identified as the CoO. Three cases had each Nepal and El Salvador identified as the CoO. Each of the following countries had one case: Zimbabwe, the U.S., the Republic of Congo, Uganda, Saudi Arabia, Liberia, and Iran.

Of the 202 spice samples collected by MDE investigators there were 52 different types of spices identified in which 53% of those spices were purchased in the U.S. As shown in Table 2, the ten most observed spice types and the mean lead levels associated with the spice. The table also shows the percentage of those spices that were purchased in the U.S. according to the case files.

In lieu of specific dietary intake and consumption data from the cases, when comparing the mean lead level of spices collected by MDE investigators of 0.548 ppm with FDA PTTIL of 6 micrograms per day, the estimated amount of spices needed to be consumed to reach the PTTIL is approximately ¾ of a Tablespoon.

Conclusions

The case reviews conducted as part of this research project found that there were 52 cases in which spices were identified as potential environmental antecedents. This study found that a large proportion of the samples collected as a direct result of the MDE case investigations as well as surveillance samples collected in Maryland and New York showed detectable levels of lead. For all of the samples collected in response to these cases, more than half had detectable limits of lead and for those samples with detectable lead levels the mean lead level was 0.549 ppm, when removing the larger outliers, which is significantly above the 0.1ppm guidance level in candy.

Recommendations

1.     Investigators should evaluate and record the consumption levels of spices if there is a suspect lead risk found during a childhood lead investigation.

2.     A national regulatory or guidance level for lead in spices should be created due to the percentage of products in which a detectable level of lead was found.

3.     Educational outreach to populations at a greater risk should be expanded by the CDC, FDA, and State lead prevention programs.

4.     Laboratories that conduct analytical testing of lead in food should use a method appropriate for solid matrices with a lower LOD allowing for comparison of results to the FDA guidance level in candy in lieu of a specific limit for lead in other foods.

5.     The methodology used in this study should be applied in a follow-up study by the MDE at some point in the future.

Acknowledgments

I would like to acknowledge the following individuals and their respective agencies for their assistance during this study. First and foremost, to Dr. D’Ann Williams for her constant guidance and contributions to the study. To the senior leadership within the Environmental Health Bureau at MDHMH particularly, Dr. Clifford Mitchell, Ms. Subha Chandar, Dr. Alan Brench, Mr. Alan Taylor, and Dr. Ann Liu. To Dr. Yingtoa Chai from MDHMH Laboratories Administration for his technical expertise. To the Lead Prevention Program Staff at MDE, particularly Ms. Paula Montgomery, Mr. Jonathan Klanderud, Mr. John Krupinsky, Mr. Wade McCord, Ms. Kirsten Held, and Mr. Nick Kyriacou, for their technical knowledge and assistance and access to their data without which this project would not have been possible. To Erin Sawyer from NYSDAM for her contributions to the study and to the IFPTI mentors particularly Mr. Joe Corby and Dr. Paul Dezendorf for all their guidance throughout the project. Finally, I would like to thank my fellow Cohort VI members, I have gained a lot professionally from sharing this experience with all of you. 

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