Profiler shows Object.ElementAddr_3_8() called over a million times. What is it? How do I reduce this?

I'm working on a voxel game, and in the profiler, under ChunkBehavior.CreateMeshAndCollision(), I see that Object.ElementAddr_3_8() is called tens of thousand of times per call of CreateMeshAndCollision(). It's creating over 70ms of delay every time I create new chunks, making my game stutter. Any idea why Object.ElementAddr_3_8() is being called so many times?

I appreciate any help. I've dropped my CreateMeshAndCollision() method below, if you'd like to take a look at it. Thanks!

 public void CreateMeshAndCollision() {
     vertices = new List<Vector3>();
     triangles = new List<int>();

     ChunkBehavior topNeighbor = tb.GetChunk(transform.position.x, transform.position.y + SIZE, transform.position.z);
     ChunkBehavior bottomNeightbor = tb.GetChunk(transform.position.x, transform.position.y - SIZE, transform.position.z);
     ChunkBehavior posXNeighbor = tb.GetChunk(transform.position.x + SIZE, transform.position.y, transform.position.z);
     ChunkBehavior negXNeighbor = tb.GetChunk(transform.position.x - SIZE, transform.position.y, transform.position.z);
     ChunkBehavior posZNeighbor = tb.GetChunk(transform.position.x, transform.position.y, transform.position.z + SIZE);
     ChunkBehavior negZNeighbor = tb.GetChunk(transform.position.x, transform.position.y, transform.position.z - SIZE);

     for (int x = 0; x < SIZE; x++) {
         for (int y = 0; y < SIZE; y++) {
             for (int z = 0; z < SIZE; z++) {
                 if (blocks[x, y, z] != null) {

                     bool needsCollision = false;

                     if (y == SIZE - 1) {
                         if (topNeighbor != null) {
                             if (!topNeighbor.BlocksVew(x, 0, z)) {
                                 blocks[x, y, z].CreateTopFace(vertices, triangles);
                                 needsCollision = true;
                             }
                         } else {
                             blocks[x, y, z].CreateTopFace(vertices, triangles);
                             needsCollision = true;
                         }
                     } else if (blocks[x, y + 1, z] == null) {
                         blocks[x, y, z].CreateTopFace(vertices, triangles);
                         needsCollision = true;
                     }
                     
                     if (y == 0) {
                         if (bottomNeightbor != null && !bottomNeightbor.BlocksVew(x, SIZE - 1, z)) {
                             blocks[x, y, z].CreateBottomFace(vertices, triangles);
                             needsCollision = true;
                         }
                     } else if (blocks[x, y - 1, z] == null) {
                         blocks[x, y, z].CreateBottomFace(vertices, triangles);
                         needsCollision = true;
                     }

                     if (x == SIZE - 1) {
                         if (posXNeighbor != null && !posXNeighbor.BlocksVew(0, y, z)) {
                             blocks[x, y, z].CreatePosXFace(vertices, triangles);
                             needsCollision = true;
                         }
                     } else if (blocks[x + 1, y, z] == null) {
                         blocks[x, y, z].CreatePosXFace(vertices, triangles);
                         needsCollision = true;
                     }

                     if (x == 0) {
                         if (negXNeighbor != null && !negXNeighbor.BlocksVew(SIZE - 1, y, z)) {
                             blocks[x, y, z].CreateNegXFace(vertices, triangles);
                             needsCollision = true;
                         }
                     } else if (blocks[x - 1, y, z] == null) {
                         blocks[x, y, z].CreateNegXFace(vertices, triangles);
                         needsCollision = true;
                     }

                     if (z == SIZE - 1) {
                         if (posZNeighbor != null && !posZNeighbor.BlocksVew(x, y, 0)) {
                             blocks[x, y, z].CreatePosZFace(vertices, triangles);
                             needsCollision = true;
                         }
                     } else if (blocks[x, y, z + 1] == null) {
                         blocks[x, y, z].CreatePosZFace(vertices, triangles);
                         needsCollision = true;
                     }

                     if (z == 0) {
                         if (negZNeighbor != null && !negZNeighbor.BlocksVew(x, y, SIZE - 1)) {
                             blocks[x, y, z].CreateNegZFace(vertices, triangles);
                             needsCollision = true;
                         }
                     } else if (blocks[x, y, z - 1] == null) {
                         blocks[x, y, z].CreateNegZFace(vertices, triangles);
                         needsCollision = true;
                     }
                     /* Don't create collision until we've fixed this problem.
                     if (needsCollision) {
                         BoxCollider newBoxCollider = gameObject.AddComponent<BoxCollider>();
                         newBoxCollider.center = new Vector3(x + .5f, y + .5f, z + .5f);
                     }*/
                 }
             }
         }
     }

     mesh = new Mesh();
     mesh.vertices = vertices.ToArray();
     mesh.triangles = triangles.ToArray();
     mesh.RecalculateNormals();
     GetComponent<MeshFilter>().mesh = mesh;
 }